Conventional Fe-C alloy parts used in mechanical transmission and braking systems exposed to the external environment often suffer from wear and corrosion failures.Surface coating strengthening technologies have been ...Conventional Fe-C alloy parts used in mechanical transmission and braking systems exposed to the external environment often suffer from wear and corrosion failures.Surface coating strengthening technologies have been explored to improve the surface performance and prolong service life of these parts.Among these technologies,laser cladding has shown promise in producing Fe-based alloy coatings with superior interfacial bonding properties to the Fe-C alloy substrate.Additionally,the microstructure of the Fe-based alloy coating is more uniform and the grain size is finer than that of surfacing welding,thermal spraying,and plasma cladding,and the oxide film of alloying elements on the coating surface can improve the coating performance.However,Fe-based alloy coatings produced by laser cladding typically exhibit lower hardness,lower wear resistance,corrosion resistance,and oxidation resistance compared to coatings based on Co and Ni alloys.Moreover,these coatings are susceptible to defects such as pores and cracks.To address these limitations,the incorporation of rare-earth oxides through doping in the laser cladding process has garnered significant attention.This approach has demonstrated substantial improvements in the microstructure and properties of Fe-based alloy coatings.This paper reviewed recent research on the structure and properties of laser-cladded Fe-based alloy coatings doped with various rare earth oxides,including La_(2)O_(3),CeO_(2),and Y_(2)O_(3).Specifically,it discussed the effects of rare earth oxides and their concentrations on the structure,hardness,friction,wear,corrosion,and oxidation characteristics of these coatings.Furthermore,the mechanisms by which rare earth oxides influence the coating’s structure and properties were summarized.This review aimed to serve as a valuable reference for the application and advancement of laser cladding technology for rare earth modified Fe-based alloy coatings.展开更多
The kagome lattice,characterized by a hexagonal arrangement of corner-sharing equilateral triangles,has garnered significant attention as a fascinating quantum material system that hosts exotic magnetic and electronic...The kagome lattice,characterized by a hexagonal arrangement of corner-sharing equilateral triangles,has garnered significant attention as a fascinating quantum material system that hosts exotic magnetic and electronic properties.The identification and characterization of this class of materials are critical for advancing our understanding of their role in emergent phenomena such as superconductivity.In this study,we developed a high-throughput screening framework for the systematic identification and classification of superconducting materials with kagome lattices,integrating them into established materials databases.Leveraging the Materials Project(MP)database and the MDR Super Con dataset,we analyzed over 150000 inorganic compounds and cross-referenced 26000 known superconductors.Using geometry-based structural modeling and experimental validation,we identified 129 kagome superconductors belonging to 17 distinct structural families,many of which had not previously been recognized as kagome systems.The materials are further classified into three categories in terms of topological flat bands,clean band structures,and coexisting magnetic or charge density wave(CDW)orderings.Based on these results,we established a database comprising 129 kagome superconductors,including the detailed crystallographic,electronic,and superconducting properties of these materials.展开更多
The discovery of high-temperature superconducting materials holds great significance for human industry and daily life.In recent years,research on predicting superconducting transition temperatures using artificial in...The discovery of high-temperature superconducting materials holds great significance for human industry and daily life.In recent years,research on predicting superconducting transition temperatures using artificial intelligence(AI)has gained popularity,with most of these tools claiming to achieve remarkable accuracy.However,the lack of widely accepted benchmark datasets in this field has severely hindered fair comparisons between different AI algorithms and impeded further advancement of these methods.In this work,we present HTSC-2025,an ambient-pressure high-temperature superconducting benchmark dataset.This comprehensive compilation encompasses theoretically predicted superconducting materials discovered by theoretical physicists from 2023 to 2025 based on BCS superconductivity theory,including the renowned X_(2)YH_(6)system,perovskite MXH_(3)system,M_(3)H_(8)system,cage-like BCN-doped metal atomic systems derived from LaH_(10)structural evolution,and two-dimensional honeycomb-structured systems evolving from MgB_(2).In addition,we note a range of approaches inspired by physical intuition for designing high-temperature superconductors,such as hole doping,the introduction of light elements to form strong covalent bonds,and the tuning of spin-orbit coupling.The dataset presented in this paper is openly available at Science DB.The HTSC-2025 benchmark has been open-sourced on Hugging Face at https://huggingface.co/datasets/xiao-qi/HTSC-2025 and will be continuously updated,while the Electronic Laboratory for Material Science platform is available at https://in.iphy.ac.cn/eln/link.html#/124/V2s4.展开更多
The effects of deep cryogenic-cycling treatment(DCT)on the mechanical properties,soft magnetic properties,and atomic scale structure of the Fe_(73.5)Si_(13.5)B_(9)Nb_(3)Cu_(1)amorphous nanocrystalline alloy were inves...The effects of deep cryogenic-cycling treatment(DCT)on the mechanical properties,soft magnetic properties,and atomic scale structure of the Fe_(73.5)Si_(13.5)B_(9)Nb_(3)Cu_(1)amorphous nanocrystalline alloy were investigated.The DCT samples were obtained by subjecting the as-annealed samples to a thermal cycling process between the temperature of the supercooled liquid zone and the temperature of liquid nitrogen.Through flat plate bending testing,hardness measurements,and nanoindentation experiment,it is found that the bending toughness of the DCT samples is improved and the soft magnetic properties are also slightly enhanced.These are attributed to the rejuvenation behavior of the DCT samples,which demonstrate a higher enthalpy of relaxation.Therefore,DCT is an effective method to enhance the bending toughness of Fe-based amorphous nanocrystalline alloys without degrading the soft magnetic properties.展开更多
Annealing has been a popular method to improve the soft magnetism of metallic glasses (MGs), which however usually makes MGs brittle and difficult to process. Here, it is demonstrated that the embrittled Fe-based MG c...Annealing has been a popular method to improve the soft magnetism of metallic glasses (MGs), which however usually makes MGs brittle and difficult to process. Here, it is demonstrated that the embrittled Fe-based MG can be reductilized and the coercivity can be further lowered through the rejuvenation of memory effect. The synchronous improvement in the plasticity and soft magnetic properties is attributed to the combination effects of releasing much residual stress, decreasing the magnetic anisotropy, and homogenizing the glasses during the rejuvenation process. The current work opens a new perspective to improve the properties of MGs by utilizing the memory effect and holds promising commercial application potential.展开更多
Sodium-ion batteries(SIBs)have the advantages of environmental friendliness,cost-effectiveness,and high energy density,which are considered one of the most promising candidates for lithium-ion batteries(LIBs).The cath...Sodium-ion batteries(SIBs)have the advantages of environmental friendliness,cost-effectiveness,and high energy density,which are considered one of the most promising candidates for lithium-ion batteries(LIBs).The cathode materials influence the cost and energy output of SIBs.Therefore,the development of advanced cathode materials is crucial for the practical application of SIBs.Among various cathode materials,layered transition metal oxides(LTMOs)have received widespread attention owing to their straightforward preparation,abundant availability,and cost-competitiveness.Notably,layered Fe-based oxide cathodes are deemed to be one of the most promising candidates for the lowest price and easy-to-improve performance.Nevertheless,the challenges such as severe phase transitions,sluggish diffusion kinetics and interfacial degradation pose significant hurdles in achieving high-performance cathodes for SIBs.This review first briefly outlines the classification of layered structures and the working principle of layered oxides.Then,recent advances in modification strategies employed to address current issues with layered iron-based oxide cathodes are systematically reviewed,including ion doping,biphasic engineering and surface modification.Furthermore,the review not only outlines the prospects and development directions for layered Fe-based oxide cathodes but also provides novel insights and directions for future research endeavors for SIBs.展开更多
Large-grain REBa_(2)Cu_(3)O_(7-δ)(REBCO,RE=rare earth)bulk superconductors offer promising magnetic field trapping capabilities due to their high critical current density,making them ideal for many important applicat...Large-grain REBa_(2)Cu_(3)O_(7-δ)(REBCO,RE=rare earth)bulk superconductors offer promising magnetic field trapping capabilities due to their high critical current density,making them ideal for many important applications such as trapped field magnets.However,for such large-grain superconductor bulks,there are lots of voids and cracks forming during the process of melting preparation,and some of them can be up to hundreds of microns or even millimeters in size.Consequently,these larger size voids/cracks pose a great threat to the strength of the bulks due to the inherent brittleness of superconductor REBCO materials.In order to ensure the operational safety of related superconducting devices with bulk superconductors,it is firstly important to accurately detect these voids/cracks in them.In this paper,we proposed a method for quantitatively evaluating multiple voids/cracks in bulk superconductors through the magnetic field and displacement response signals at superconductor bulk surface.The proposed method utilizes a damage index constructed from the magnetic field signals and displacement responses to identify the number and preliminary location of multiple defects.By dividing the detection area into subdomains and combining the magnetic field signals with displacement responses within each subdomain,a particle swarm algorithm was employed to evaluate the location and size parameters of the defects.In contrast to other evaluation methods using only magnetic field or displacement response signals,the combined evaluation method using both signals can identify the number of cracks effectively.Numerical studies demonstrate that the morphology of voids and cracks reconstructed using the proposed algorithm ideally matches real defects and is applicable to cases where voids and cracks coexist.This study provides a theoretical basis for the quantitative detection of voids/cracks in bulk superconductors.展开更多
The discovery of new superconducting materials,particularly those exhibiting high critical temperature(Tc),has been a vibrant area of study within the field of condensed matter physics.Conventional approaches primaril...The discovery of new superconducting materials,particularly those exhibiting high critical temperature(Tc),has been a vibrant area of study within the field of condensed matter physics.Conventional approaches primarily rely on physical intuition to search for potential superconductors within the existing databases.However,the known materials only scratch the surface of the extensive array of possibilities within the realm of materials.展开更多
Compared to traditional superhard materials with high electron density and short,strong covalent bonds,alloy materials mainly composed of metallic bonding structures typically have great toughness and lower hardness.B...Compared to traditional superhard materials with high electron density and short,strong covalent bonds,alloy materials mainly composed of metallic bonding structures typically have great toughness and lower hardness.Breaking through the limits of alloy materials is a preface and long-term topic,which is of great significance and value for improving the comprehensive mechanical properties of alloy materials.Here,we report on the discovery of a cubic alloy semiconducting material Ti_(2)Co with a large Vickers of hardness K_(v)^(exp)∼6.7GPa and low fracture toughness of K_(IC)^(exp)∼1.51MPa·m^(1/2).Unexpectedly,the K_(v)^(exp)∼6.7GPa is nearly triple of the K_(v)^(cal)∼2.66GPa predicted by density functional theory(DFT)calculations and theK_(IC)^(exp)∼1.51MPa·m^(1/2)is about one or two orders of magnitude smaller than that of ordinary titanium alloy materials(K_(IC)^(exp)∼30-120MPa·m^(1/2)).These specifications place Ti_(2)Co far from the phase space of the known alloy materials.Upon incorporation of oxygen into structural void positions,both values were simultaneously improved for Ti_(4)Co_(2)O to∼9.7GPa and∼2.19MPa·m^(1/2),respectively.Further DFT calculations on the electron localization function of Ti_(4)Co_(2)X(X=B,C,N,O)vs.the interstitial elements indicate that these simultaneous improvements originate from the coexistence of Ti-Co metallic bonds,the emergence of newly oriented Ti-X covalent bonds,and the increase of electron concentration.Moreover,the large difference between K_(v)^(exp)and K_(v)^(cal)of Ti_(2)Co suggests underlying mechanism concerning the absence of the O(16d)or Ti_(2)-O bonds in the O-(Ti_(2))_(6) octahedron.This discovery proposes a new pathway to simultaneously improve the comprehensive mechanical performances and illuminates the path of exploring superconducting materials with excellent mechanical performances.展开更多
The discovered in 2008 Fe-based superconductors (SC) are a paramagnetic semimetal at ambient temperature and in some cases they become superconductor upon doping. In spite of so many years since its discovery it is st...The discovered in 2008 Fe-based superconductors (SC) are a paramagnetic semimetal at ambient temperature and in some cases they become superconductor upon doping. In spite of so many years since its discovery it is still not known the mechanism that leads to superconductivity. The electronic structure study is used for determining key features of the SC mechanism in these materials. The calculations were performed using the modern suite of programs MOLPRO 2021. We performed quantum calculations of a cluster embedded in a background charge distribution that represents the infinite crystal. The Natural Population Analysis was used for determining the charge and spin distribution in the studied materials. As follows from our results, the possible mechanism for superconductivity corresponds to the RVB theory proposed by Anderson for high T<sub>c</sub> superconductivity in cuprates.展开更多
What factors fundamentally determine the value of superconducting transition temperature Tc in high temperature superconductors has been the subject of intense debate.Following the establishment of an empirical law kn...What factors fundamentally determine the value of superconducting transition temperature Tc in high temperature superconductors has been the subject of intense debate.Following the establishment of an empirical law known as Homes'law,there is a growing consensus in the community that the Tc value of the cuprate superconductors is closely linked to the superfluid density(ρ_(s))of its ground state and the conductivity(σ)of its normal state.However,all the data supporting this empirical law(ρ_(s)=AσT_(c))have been obtained from the ambientpressure superconductors.In this study,we present the first high-pressure results about the connection of the quantities ofρ_(s)andσwith T_(c),through the studies on the Bi_(1.74)Pb_(0.38)Sr_(1.88)CuO_(6+δ)and Bi_(2)Sr_(2)CaCu_(2)O_(8+δ),in which the value of their high-pressure resistivity(ρ=1/σ)is achieved by adopting our newly established method,while the quantity ofρs is extracted using Homes'law.We highlight that the Tc values are strongly linked to the joint response factors of magnetic field and electric field,i.e.,ρ_(s)andσ,respectively,implying that the physics determining T_(c)is governed by the intrinsic electromagnetic fields of the system.展开更多
Fe-based metallic glasses have garnered significant attention due to their low coercivity force and core loss.Enhancing the saturation magnetic flux density(Bs)of Fe-based metallic glasses is crucial for their industr...Fe-based metallic glasses have garnered significant attention due to their low coercivity force and core loss.Enhancing the saturation magnetic flux density(Bs)of Fe-based metallic glasses is crucial for their industry applications.This work constructed a dataset comprising330 training data and 157 test data.The support vector regression model surpassed the tree-based ensemble models in the test set and demonstrated comparable accuracy to the tree-based ensemble models in the training set.Additionally,we proposed an indicator for Bsbased on symbolic regression.This newly proposed indicator exhibits a Pearson correlation coefficient exceeding 0.92 with Bs.The present work provides a simple and accurate formula for predicting the Bsof Fe-based amorphous alloys,demonstrating the effectiveness of machine learning approaches in discovering novel soft magnetic materials.展开更多
Since the discovery of hydride superconductors,a significant challenge has been to reduce the pressure required for their stabilization.In this context,we propose that alloying could be an effective strategy to achiev...Since the discovery of hydride superconductors,a significant challenge has been to reduce the pressure required for their stabilization.In this context,we propose that alloying could be an effective strategy to achieve this.We focus on a series of alloyed hydrides with the AMH_(6)composition,which can be made via alloying A15 AH_(3)(A=Al or Ga)with M(M=a group IIIB or IVB metal),and study their behavior under pressure.Seven of them are predicted to maintain the A15-type structure,similar to AH_(3)under pressure,providing a platform for studying the effects of alloying on the stability and superconductivity of AH_(3).Among these,the A15-type phases of AlZrH_(6)and AlHfH_(6)are found to be thermodynamically stable in the pressure ranges of 40–150 and 30–181 GPa,respectively.Furthermore,they remain dynamically stable at even lower pressures,as low as 13 GPa for AlZrH_(6)and 6 GPa for AlHfH_(6).These pressures are significantly lower than that required for stabilizing A15 AlH3.Additionally,the introduction of Zr or Hf increases the electronic density of states at the Fermi level compared with AlH3.This enhancement leads to higher critical temperatures(Tc)of 75 and 76 K for AlZrH_(6)and AlHfH_(6)at 20 and 10 GPa,respectively.In the case of GaMH_(6)alloys,where M represents Sc,Ti,Zr,or Hf,these metals reinforce the stability of the A15-type structure and reduce the lowest thermodynamically stable pressure for GaH_(3) from 160 GPa to 116,95,80,and 85 GPa,respectively.Particularly noteworthy are the A15-type GaMH_(6)alloys,which remain dynamically stable at low pressures of 97,28,5,and 6 GPa,simultaneously exhibiting high Tc of 88,39,70,and 49 K at 100,35,10,and 10 GPa,respectively.Overall,these findings enrich the family of A15-type superconductors and provide insights for the future exploration of high-temperature hydride superconductors that can be stabilized at lower pressures.展开更多
Fe-based Prussian blue(Fe-PB)cathode material shows great application potential in sodium(Na)-ion batteries due to its high theoretical capacity,long cycle life,low cost,and simple preparation process.However,the crys...Fe-based Prussian blue(Fe-PB)cathode material shows great application potential in sodium(Na)-ion batteries due to its high theoretical capacity,long cycle life,low cost,and simple preparation process.However,the crystalline water and vacancies of Fe-PB lattice,the low electrical conductivity,and the dissolution of metal ions lead to limited capacity and poor cycling stability.In this work,a perylene tetracarboxylic dianhydride amine(PTCDA)coating layer is successfully fabricated on the surface of Fe-PB by a liquid-phase method.The aminated PTCDA(PTCA)coating not only increases the specific surface area and electronic conductivity but also effectively reduces the crystalline water and vacancies,which avoids the erosion of Fe-PB by electrolyte.Consequently,the PTCA layer reduces the charge transfer resistance,enhances the Na-ion diffusion coefficient,and improves the structure stability.The PTCA-coated Fe-PB exhibits superior Na storage performance with a first discharge capacity of 145.2 mAh g^(−1)at 100 mA g^(−1).Long cycling tests exhibit minimal capacity decay of 0.027%per cycle over 1000 cycles at 1 A g^(−1).Therefore,this PTCA coating strategy has shown promising competence in enhancing the electrochemical performance of Fe-PB,which can potentially serve as a universal electrode coating strategy for Na-ion batteries.展开更多
The high-entropy alloy(HEA)superconductor,Ta_(1/6)Nb_(2/6)Hf_(1/6)Zr_(1/6)Ti_(1/6)(Ta-Nb-Hf-Zr-Ti),is systematically studied to examine changes in superconducting critical properties,critical temperature(T_(c)),critic...The high-entropy alloy(HEA)superconductor,Ta_(1/6)Nb_(2/6)Hf_(1/6)Zr_(1/6)Ti_(1/6)(Ta-Nb-Hf-Zr-Ti),is systematically studied to examine changes in superconducting critical properties,critical temperature(T_(c)),critical cur-rent density(J_(c)),and upper critical field(H_(c2)),concerning thermal treatment conditions.Annealing condi-tion affects Jc more significantly than T_(c)and H_(c2),with a large improvement of flux pinning force density(F_(p)).The Jc of bare sample is reduced to 10 A cm^(-2)at an applied magnetic field of approximately 1.5 T,whereas the sample annealed at 550℃for 12 h exhibits J_(c)>100 kA cm^(-2)up to around 4 T.Furthermore,the Vickers hardness(HVIT)of the Ta-Nb-Hf-Zr-Ti HEA superconductor notably increases from∼384 to 528 HVIT following a 24-h annealing at 500℃.These results demonstrate that thermal annealing is a powerful process to optimize both the superconducting and mechanical properties of high-entropy alloy superconductors.展开更多
In 1937, Italian theoretical physicist Ettore Majorana published a paper, in which he made a brilliant discovery by decomposing Dirac equation into the real and imaginary parts. That is the famous equation describing ...In 1937, Italian theoretical physicist Ettore Majorana published a paper, in which he made a brilliant discovery by decomposing Dirac equation into the real and imaginary parts. That is the famous equation describing the motion of a Majorana fermion whose antiparticle is itself.展开更多
We design two new layered indium halide compounds LaOInF_(2)and LaOInCl_(2)by means of first-principles calculations and evolutionary crystal structure prediction.We find both compounds crystallize in a tetragonal str...We design two new layered indium halide compounds LaOInF_(2)and LaOInCl_(2)by means of first-principles calculations and evolutionary crystal structure prediction.We find both compounds crystallize in a tetragonal structure with P4/nmm space group and have indirect band gaps of 2.58 eV and 3.21 eV,respectively.By substituting O with F,both of them become metallic and superconducting at low temperature.The F-doping leads to strong electron-phonon coupling in the low-energy acoustic phonon modes which is mainly responsible for the induced superconductivity.The total electron-phonon coupling strength are 1.86 and 1.48,while the superconducting transition temperature(T_(c))are about 7.2 K and 6.5 K with 10%and 5%F doping for LaOInF_(2)and LaOInCl_(2),respectively.展开更多
We construct a doped holographic superconductor in the Gubser–Rocha model,and realize a superconducting dome in the middle of the temperature-doping phase diagram.It is worth noting that unlike in previous research,t...We construct a doped holographic superconductor in the Gubser–Rocha model,and realize a superconducting dome in the middle of the temperature-doping phase diagram.It is worth noting that unlike in previous research,the profile of our dome shrinks inward near to zero temperature.From the numerical observation for the coupling dependence of the phase diagram,we find that the coupling between the two gauge fields plays a crucial role in the formation of the dome.We also analytically calculate the DC conductivity of the normal phase of the system in the momentum dissipation and obtain resistivity which is proportional to the temperature.The AC conductivity is calculated numerically.展开更多
We construct a three-dimensional topological superconductor Bogoliubov–de Gennes(BdG)Hamiltonian with the normal state being a three-dimensional topological insulator.By introducing inter-orbital spin-triplet pairing...We construct a three-dimensional topological superconductor Bogoliubov–de Gennes(BdG)Hamiltonian with the normal state being a three-dimensional topological insulator.By introducing inter-orbital spin-triplet pairings term△3,there are topological Majorana nodes in the bulk and they are connected by Majorana Fermi arcs on the surface,similar to the case of Weyl semimetal.Furthermore,by adding an inversion-breaking term to the normal state,momentum-independent pairing terms with different parities can coexist in the Bd G Hamiltonian,which creates more Majorana modes similar to Andreev bound states and a richer phase diagram.展开更多
Metallurgical dust(MD)was used as raw material to prepare rare earth Ce-doped Fe-based catalysts.The results show that the Ce_(0.1)/AMD-300℃catalyst prepared from acid-modified diatomite(AMD)with mCe/mMD=0.1(m_(Ce)an...Metallurgical dust(MD)was used as raw material to prepare rare earth Ce-doped Fe-based catalysts.The results show that the Ce_(0.1)/AMD-300℃catalyst prepared from acid-modified diatomite(AMD)with mCe/mMD=0.1(m_(Ce)and m_(MD)are the mass of Ce and MD,respectively)after being roasted at 300℃can reach 99%NO_(x)removal rate in the wide temperature range of 230–430℃and exhibits excellent So_(2)and H_(2)o resistance.The MD effectively removes alkali metal elements by the modification process,increases the specific surface area and optimizes the pore structure of MD.The doping of Ce element makes Fe-based catalysts have more surface adsorbed oxygen O_(α)and a higher Ce^(3+)/Ce^(4+)ratio.Through ammonia temperature-programmed desorption and hydrogen temperature-programmed reduction,it was found that the strong interaction between cerium and iron promotes the formation of more oxygen cavities in the catalyst,thereby generating more active and easily reducible oxygen species and promoting the transformation of Brønsted acid site to Lewis acid site.The research results provide a theoretical basis for the preparation of efficient and inexpensive Fe-based catalysts from MD.展开更多
基金supported by the Jiangxi Provincial Natural Science Foundation of China(Grant number 20224BAB204049)the National Natural Science Foundation of China(Grant number 52205194)the Fund Project of Jiangxi Provincial Department of Education(Grant number GJJ2200602)。
文摘Conventional Fe-C alloy parts used in mechanical transmission and braking systems exposed to the external environment often suffer from wear and corrosion failures.Surface coating strengthening technologies have been explored to improve the surface performance and prolong service life of these parts.Among these technologies,laser cladding has shown promise in producing Fe-based alloy coatings with superior interfacial bonding properties to the Fe-C alloy substrate.Additionally,the microstructure of the Fe-based alloy coating is more uniform and the grain size is finer than that of surfacing welding,thermal spraying,and plasma cladding,and the oxide film of alloying elements on the coating surface can improve the coating performance.However,Fe-based alloy coatings produced by laser cladding typically exhibit lower hardness,lower wear resistance,corrosion resistance,and oxidation resistance compared to coatings based on Co and Ni alloys.Moreover,these coatings are susceptible to defects such as pores and cracks.To address these limitations,the incorporation of rare-earth oxides through doping in the laser cladding process has garnered significant attention.This approach has demonstrated substantial improvements in the microstructure and properties of Fe-based alloy coatings.This paper reviewed recent research on the structure and properties of laser-cladded Fe-based alloy coatings doped with various rare earth oxides,including La_(2)O_(3),CeO_(2),and Y_(2)O_(3).Specifically,it discussed the effects of rare earth oxides and their concentrations on the structure,hardness,friction,wear,corrosion,and oxidation characteristics of these coatings.Furthermore,the mechanisms by which rare earth oxides influence the coating’s structure and properties were summarized.This review aimed to serve as a valuable reference for the application and advancement of laser cladding technology for rare earth modified Fe-based alloy coatings.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFE0202600)the National Natural Science Foundation of China(Grant No.52272268)+3 种基金the Key Research Program of Frontier SciencesCAS(Grant No.QYZDJ-SSWSLH013)the Informatization Plan of Chinese Academy of Sciences(Grant No.CAS-WX2021SF-0102)the Youth Innovation Promotion Association of CAS(Grant No.2019005)。
文摘The kagome lattice,characterized by a hexagonal arrangement of corner-sharing equilateral triangles,has garnered significant attention as a fascinating quantum material system that hosts exotic magnetic and electronic properties.The identification and characterization of this class of materials are critical for advancing our understanding of their role in emergent phenomena such as superconductivity.In this study,we developed a high-throughput screening framework for the systematic identification and classification of superconducting materials with kagome lattices,integrating them into established materials databases.Leveraging the Materials Project(MP)database and the MDR Super Con dataset,we analyzed over 150000 inorganic compounds and cross-referenced 26000 known superconductors.Using geometry-based structural modeling and experimental validation,we identified 129 kagome superconductors belonging to 17 distinct structural families,many of which had not previously been recognized as kagome systems.The materials are further classified into three categories in terms of topological flat bands,clean band structures,and coexisting magnetic or charge density wave(CDW)orderings.Based on these results,we established a database comprising 129 kagome superconductors,including the detailed crystallographic,electronic,and superconducting properties of these materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.62476278,12434009,12204533)the National Key R&D Program of China(Grant No.2024YFA1408601)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302402)。
文摘The discovery of high-temperature superconducting materials holds great significance for human industry and daily life.In recent years,research on predicting superconducting transition temperatures using artificial intelligence(AI)has gained popularity,with most of these tools claiming to achieve remarkable accuracy.However,the lack of widely accepted benchmark datasets in this field has severely hindered fair comparisons between different AI algorithms and impeded further advancement of these methods.In this work,we present HTSC-2025,an ambient-pressure high-temperature superconducting benchmark dataset.This comprehensive compilation encompasses theoretically predicted superconducting materials discovered by theoretical physicists from 2023 to 2025 based on BCS superconductivity theory,including the renowned X_(2)YH_(6)system,perovskite MXH_(3)system,M_(3)H_(8)system,cage-like BCN-doped metal atomic systems derived from LaH_(10)structural evolution,and two-dimensional honeycomb-structured systems evolving from MgB_(2).In addition,we note a range of approaches inspired by physical intuition for designing high-temperature superconductors,such as hole doping,the introduction of light elements to form strong covalent bonds,and the tuning of spin-orbit coupling.The dataset presented in this paper is openly available at Science DB.The HTSC-2025 benchmark has been open-sourced on Hugging Face at https://huggingface.co/datasets/xiao-qi/HTSC-2025 and will be continuously updated,while the Electronic Laboratory for Material Science platform is available at https://in.iphy.ac.cn/eln/link.html#/124/V2s4.
基金supported by Liaoning Joint Fund of NSFC(No.U1908219)。
文摘The effects of deep cryogenic-cycling treatment(DCT)on the mechanical properties,soft magnetic properties,and atomic scale structure of the Fe_(73.5)Si_(13.5)B_(9)Nb_(3)Cu_(1)amorphous nanocrystalline alloy were investigated.The DCT samples were obtained by subjecting the as-annealed samples to a thermal cycling process between the temperature of the supercooled liquid zone and the temperature of liquid nitrogen.Through flat plate bending testing,hardness measurements,and nanoindentation experiment,it is found that the bending toughness of the DCT samples is improved and the soft magnetic properties are also slightly enhanced.These are attributed to the rejuvenation behavior of the DCT samples,which demonstrate a higher enthalpy of relaxation.Therefore,DCT is an effective method to enhance the bending toughness of Fe-based amorphous nanocrystalline alloys without degrading the soft magnetic properties.
基金support from the National Natural Science Foundation of China(No.52231006)Junqiang Wang acknowledges financial support from the National Key R&D Program of China(No.2018YFA0703600)the National Natural Science Foundation of China(Nos.92163108 and 52222105).
文摘Annealing has been a popular method to improve the soft magnetism of metallic glasses (MGs), which however usually makes MGs brittle and difficult to process. Here, it is demonstrated that the embrittled Fe-based MG can be reductilized and the coercivity can be further lowered through the rejuvenation of memory effect. The synchronous improvement in the plasticity and soft magnetic properties is attributed to the combination effects of releasing much residual stress, decreasing the magnetic anisotropy, and homogenizing the glasses during the rejuvenation process. The current work opens a new perspective to improve the properties of MGs by utilizing the memory effect and holds promising commercial application potential.
基金supported by the National Natural Science Foundation of China(no.52374301)the Open Project of Guangxi Key Laboratory of Electrochemical Energy Materials(no.GXUEEM2024001)+2 种基金the Hebei Provincial Natural Science Foundation(no.E2024501010)the Shijiazhuang Basic Research Project(no.241790667A)the Performance subsidy fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province(no.22567627H)。
文摘Sodium-ion batteries(SIBs)have the advantages of environmental friendliness,cost-effectiveness,and high energy density,which are considered one of the most promising candidates for lithium-ion batteries(LIBs).The cathode materials influence the cost and energy output of SIBs.Therefore,the development of advanced cathode materials is crucial for the practical application of SIBs.Among various cathode materials,layered transition metal oxides(LTMOs)have received widespread attention owing to their straightforward preparation,abundant availability,and cost-competitiveness.Notably,layered Fe-based oxide cathodes are deemed to be one of the most promising candidates for the lowest price and easy-to-improve performance.Nevertheless,the challenges such as severe phase transitions,sluggish diffusion kinetics and interfacial degradation pose significant hurdles in achieving high-performance cathodes for SIBs.This review first briefly outlines the classification of layered structures and the working principle of layered oxides.Then,recent advances in modification strategies employed to address current issues with layered iron-based oxide cathodes are systematically reviewed,including ion doping,biphasic engineering and surface modification.Furthermore,the review not only outlines the prospects and development directions for layered Fe-based oxide cathodes but also provides novel insights and directions for future research endeavors for SIBs.
基金supported by the National Natural Science Foundation of China(Grant Nos.12232005 and 12072101).
文摘Large-grain REBa_(2)Cu_(3)O_(7-δ)(REBCO,RE=rare earth)bulk superconductors offer promising magnetic field trapping capabilities due to their high critical current density,making them ideal for many important applications such as trapped field magnets.However,for such large-grain superconductor bulks,there are lots of voids and cracks forming during the process of melting preparation,and some of them can be up to hundreds of microns or even millimeters in size.Consequently,these larger size voids/cracks pose a great threat to the strength of the bulks due to the inherent brittleness of superconductor REBCO materials.In order to ensure the operational safety of related superconducting devices with bulk superconductors,it is firstly important to accurately detect these voids/cracks in them.In this paper,we proposed a method for quantitatively evaluating multiple voids/cracks in bulk superconductors through the magnetic field and displacement response signals at superconductor bulk surface.The proposed method utilizes a damage index constructed from the magnetic field signals and displacement responses to identify the number and preliminary location of multiple defects.By dividing the detection area into subdomains and combining the magnetic field signals with displacement responses within each subdomain,a particle swarm algorithm was employed to evaluate the location and size parameters of the defects.In contrast to other evaluation methods using only magnetic field or displacement response signals,the combined evaluation method using both signals can identify the number of cracks effectively.Numerical studies demonstrate that the morphology of voids and cracks reconstructed using the proposed algorithm ideally matches real defects and is applicable to cases where voids and cracks coexist.This study provides a theoretical basis for the quantitative detection of voids/cracks in bulk superconductors.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.62476278,12434009,and 12204533)the National Key R&D Program of China(Grant No.2024YFA1408601)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302402)。
文摘The discovery of new superconducting materials,particularly those exhibiting high critical temperature(Tc),has been a vibrant area of study within the field of condensed matter physics.Conventional approaches primarily rely on physical intuition to search for potential superconductors within the existing databases.However,the known materials only scratch the surface of the extensive array of possibilities within the realm of materials.
基金supported by the National Key Research and Development Program of China(Grant Nos.2024YFA1408400,2023YFA1406100,2023YFA1607400,2022YFA1403800,and 2022YFA1403203)the National Natural Science Foundation of China(Grant Nos.12474055,12404067,12025408,52025026,and U23A6003)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB33000000)the Chinese Academy of Sciences President’s International Fellowship Initiative(Grant No.2024PG0003)the Outstanding Member of Youth Promotion Association of Chinese Academy of Sciences(Grant No.Y2022004)supported by the CAC station of Synergetic Extreme Condition User Facility(SECUF,https://cstr.cn/31123.02.SECUF)。
文摘Compared to traditional superhard materials with high electron density and short,strong covalent bonds,alloy materials mainly composed of metallic bonding structures typically have great toughness and lower hardness.Breaking through the limits of alloy materials is a preface and long-term topic,which is of great significance and value for improving the comprehensive mechanical properties of alloy materials.Here,we report on the discovery of a cubic alloy semiconducting material Ti_(2)Co with a large Vickers of hardness K_(v)^(exp)∼6.7GPa and low fracture toughness of K_(IC)^(exp)∼1.51MPa·m^(1/2).Unexpectedly,the K_(v)^(exp)∼6.7GPa is nearly triple of the K_(v)^(cal)∼2.66GPa predicted by density functional theory(DFT)calculations and theK_(IC)^(exp)∼1.51MPa·m^(1/2)is about one or two orders of magnitude smaller than that of ordinary titanium alloy materials(K_(IC)^(exp)∼30-120MPa·m^(1/2)).These specifications place Ti_(2)Co far from the phase space of the known alloy materials.Upon incorporation of oxygen into structural void positions,both values were simultaneously improved for Ti_(4)Co_(2)O to∼9.7GPa and∼2.19MPa·m^(1/2),respectively.Further DFT calculations on the electron localization function of Ti_(4)Co_(2)X(X=B,C,N,O)vs.the interstitial elements indicate that these simultaneous improvements originate from the coexistence of Ti-Co metallic bonds,the emergence of newly oriented Ti-X covalent bonds,and the increase of electron concentration.Moreover,the large difference between K_(v)^(exp)and K_(v)^(cal)of Ti_(2)Co suggests underlying mechanism concerning the absence of the O(16d)or Ti_(2)-O bonds in the O-(Ti_(2))_(6) octahedron.This discovery proposes a new pathway to simultaneously improve the comprehensive mechanical performances and illuminates the path of exploring superconducting materials with excellent mechanical performances.
文摘The discovered in 2008 Fe-based superconductors (SC) are a paramagnetic semimetal at ambient temperature and in some cases they become superconductor upon doping. In spite of so many years since its discovery it is still not known the mechanism that leads to superconductivity. The electronic structure study is used for determining key features of the SC mechanism in these materials. The calculations were performed using the modern suite of programs MOLPRO 2021. We performed quantum calculations of a cluster embedded in a background charge distribution that represents the infinite crystal. The Natural Population Analysis was used for determining the charge and spin distribution in the studied materials. As follows from our results, the possible mechanism for superconductivity corresponds to the RVB theory proposed by Anderson for high T<sub>c</sub> superconductivity in cuprates.
基金supported by the National Key Research and Development Program of China(Grant Nos.2021YFA1401800 and 2022YFA1403900)the National Natural Science Foundation of China(Grant Nos.U2032214,12122414,12104487,and 12004419)+1 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB25000000)supported by the US Department of Energy,Office of Basic Energy Sciences(Grant No.DOE-sc0012704)。
文摘What factors fundamentally determine the value of superconducting transition temperature Tc in high temperature superconductors has been the subject of intense debate.Following the establishment of an empirical law known as Homes'law,there is a growing consensus in the community that the Tc value of the cuprate superconductors is closely linked to the superfluid density(ρ_(s))of its ground state and the conductivity(σ)of its normal state.However,all the data supporting this empirical law(ρ_(s)=AσT_(c))have been obtained from the ambientpressure superconductors.In this study,we present the first high-pressure results about the connection of the quantities ofρ_(s)andσwith T_(c),through the studies on the Bi_(1.74)Pb_(0.38)Sr_(1.88)CuO_(6+δ)and Bi_(2)Sr_(2)CaCu_(2)O_(8+δ),in which the value of their high-pressure resistivity(ρ=1/σ)is achieved by adopting our newly established method,while the quantity ofρs is extracted using Homes'law.We highlight that the Tc values are strongly linked to the joint response factors of magnetic field and electric field,i.e.,ρ_(s)andσ,respectively,implying that the physics determining T_(c)is governed by the intrinsic electromagnetic fields of the system.
基金financially supported by Shanghai Pujiang Program(No.23PJ1403500)GuangDong Basic and Applied Basic Research Foundation(No.2023A1515110901)+2 种基金Shenzhen Pengcheng Peacock Project(No.NA11409004)the National Natural Science Foundation of China(Nos.U22B2064 and 51105102)and Shanghai Rising-Star Program Yangfan Project(No.23YF1411900)。
文摘Fe-based metallic glasses have garnered significant attention due to their low coercivity force and core loss.Enhancing the saturation magnetic flux density(Bs)of Fe-based metallic glasses is crucial for their industry applications.This work constructed a dataset comprising330 training data and 157 test data.The support vector regression model surpassed the tree-based ensemble models in the test set and demonstrated comparable accuracy to the tree-based ensemble models in the training set.Additionally,we proposed an indicator for Bsbased on symbolic regression.This newly proposed indicator exhibits a Pearson correlation coefficient exceeding 0.92 with Bs.The present work provides a simple and accurate formula for predicting the Bsof Fe-based amorphous alloys,demonstrating the effectiveness of machine learning approaches in discovering novel soft magnetic materials.
基金supported by the Natural Science Foundation of China(Grant Nos.52022089,52372261,52288102,and 11964026)the National Key R&D Program of China(Grant No.2022YFA1402300)+5 种基金the Natural Science Foundation of Hebei Province(Grant No.E2022203109)the Doctoral Fund of Henan University of Technology(Grant No.31401579)P.L.thanks the Science and Technology Leading Talents and Innovation Team Building Projects of the Inner Mongolia Autonomous Region(Grant No.GXKY22060)financial support from the Spanish Ministry of Science and Innovation(Grant No.FIS2019-105488GB-I00)the Department of Education,Universities and Research of the Basque Government and the University of the Basque Country(Grant No.IT1707-22)the National Science Foundation(Grant No.DMR-2136038)for financial support.
文摘Since the discovery of hydride superconductors,a significant challenge has been to reduce the pressure required for their stabilization.In this context,we propose that alloying could be an effective strategy to achieve this.We focus on a series of alloyed hydrides with the AMH_(6)composition,which can be made via alloying A15 AH_(3)(A=Al or Ga)with M(M=a group IIIB or IVB metal),and study their behavior under pressure.Seven of them are predicted to maintain the A15-type structure,similar to AH_(3)under pressure,providing a platform for studying the effects of alloying on the stability and superconductivity of AH_(3).Among these,the A15-type phases of AlZrH_(6)and AlHfH_(6)are found to be thermodynamically stable in the pressure ranges of 40–150 and 30–181 GPa,respectively.Furthermore,they remain dynamically stable at even lower pressures,as low as 13 GPa for AlZrH_(6)and 6 GPa for AlHfH_(6).These pressures are significantly lower than that required for stabilizing A15 AlH3.Additionally,the introduction of Zr or Hf increases the electronic density of states at the Fermi level compared with AlH3.This enhancement leads to higher critical temperatures(Tc)of 75 and 76 K for AlZrH_(6)and AlHfH_(6)at 20 and 10 GPa,respectively.In the case of GaMH_(6)alloys,where M represents Sc,Ti,Zr,or Hf,these metals reinforce the stability of the A15-type structure and reduce the lowest thermodynamically stable pressure for GaH_(3) from 160 GPa to 116,95,80,and 85 GPa,respectively.Particularly noteworthy are the A15-type GaMH_(6)alloys,which remain dynamically stable at low pressures of 97,28,5,and 6 GPa,simultaneously exhibiting high Tc of 88,39,70,and 49 K at 100,35,10,and 10 GPa,respectively.Overall,these findings enrich the family of A15-type superconductors and provide insights for the future exploration of high-temperature hydride superconductors that can be stabilized at lower pressures.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFB3807700Hubei Natural Science Foundation Innovation Group Project,Grant/Award Number:2022CFA020+2 种基金Joint Funds of the Hubei Natural Science Foundation Innovation and Development,Grant/Award Number:2022CFD034Major Technological Innovation Project of Hubei Science and Technology Department,Grant/Award Number:2019AAA164National Natural Science Foundation of China,Grant/Award Number:2022CFD034。
文摘Fe-based Prussian blue(Fe-PB)cathode material shows great application potential in sodium(Na)-ion batteries due to its high theoretical capacity,long cycle life,low cost,and simple preparation process.However,the crystalline water and vacancies of Fe-PB lattice,the low electrical conductivity,and the dissolution of metal ions lead to limited capacity and poor cycling stability.In this work,a perylene tetracarboxylic dianhydride amine(PTCDA)coating layer is successfully fabricated on the surface of Fe-PB by a liquid-phase method.The aminated PTCDA(PTCA)coating not only increases the specific surface area and electronic conductivity but also effectively reduces the crystalline water and vacancies,which avoids the erosion of Fe-PB by electrolyte.Consequently,the PTCA layer reduces the charge transfer resistance,enhances the Na-ion diffusion coefficient,and improves the structure stability.The PTCA-coated Fe-PB exhibits superior Na storage performance with a first discharge capacity of 145.2 mAh g^(−1)at 100 mA g^(−1).Long cycling tests exhibit minimal capacity decay of 0.027%per cycle over 1000 cycles at 1 A g^(−1).Therefore,this PTCA coating strategy has shown promising competence in enhancing the electrochemical performance of Fe-PB,which can potentially serve as a universal electrode coating strategy for Na-ion batteries.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MIST)(Nos.2021R1A2C2010925,RS-2023-00240326,and RS-2023-00220471)Basic Science Research Program through the NRF of Korea funded by the Ministry of Education(Nos.NRF-2019R1F1A1055284 and NRF-2021R1I1A1A01043885).
文摘The high-entropy alloy(HEA)superconductor,Ta_(1/6)Nb_(2/6)Hf_(1/6)Zr_(1/6)Ti_(1/6)(Ta-Nb-Hf-Zr-Ti),is systematically studied to examine changes in superconducting critical properties,critical temperature(T_(c)),critical cur-rent density(J_(c)),and upper critical field(H_(c2)),concerning thermal treatment conditions.Annealing condi-tion affects Jc more significantly than T_(c)and H_(c2),with a large improvement of flux pinning force density(F_(p)).The Jc of bare sample is reduced to 10 A cm^(-2)at an applied magnetic field of approximately 1.5 T,whereas the sample annealed at 550℃for 12 h exhibits J_(c)>100 kA cm^(-2)up to around 4 T.Furthermore,the Vickers hardness(HVIT)of the Ta-Nb-Hf-Zr-Ti HEA superconductor notably increases from∼384 to 528 HVIT following a 24-h annealing at 500℃.These results demonstrate that thermal annealing is a powerful process to optimize both the superconducting and mechanical properties of high-entropy alloy superconductors.
基金supported by grants from the Ministry of Science and Technology of China(2013CBA01600,2015CB921000,2015CB921300,2016YFA0202300)the National Natural Science Foundation of China(11234014,11574371,61390501)CAS(XDPB08-1,XDB07000000,XDPB0601)
文摘In 1937, Italian theoretical physicist Ettore Majorana published a paper, in which he made a brilliant discovery by decomposing Dirac equation into the real and imaginary parts. That is the famous equation describing the motion of a Majorana fermion whose antiparticle is itself.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2243300003)the National Natural Science Foundation of China(Grant No.12074041)the Fundamental Research Program of Shanxi Province,China(Grant No.202203021222228).The calculations were carried out with high performance computing cluster of Beijing Normal University in Zhuhai.
文摘We design two new layered indium halide compounds LaOInF_(2)and LaOInCl_(2)by means of first-principles calculations and evolutionary crystal structure prediction.We find both compounds crystallize in a tetragonal structure with P4/nmm space group and have indirect band gaps of 2.58 eV and 3.21 eV,respectively.By substituting O with F,both of them become metallic and superconducting at low temperature.The F-doping leads to strong electron-phonon coupling in the low-energy acoustic phonon modes which is mainly responsible for the induced superconductivity.The total electron-phonon coupling strength are 1.86 and 1.48,while the superconducting transition temperature(T_(c))are about 7.2 K and 6.5 K with 10%and 5%F doping for LaOInF_(2)and LaOInCl_(2),respectively.
基金supported by the National Natural Science Foundation of China(Grant Nos.12275166,11875184,12147158 and 11805117)the NFSC-NFR joint program 12311540141.
文摘We construct a doped holographic superconductor in the Gubser–Rocha model,and realize a superconducting dome in the middle of the temperature-doping phase diagram.It is worth noting that unlike in previous research,the profile of our dome shrinks inward near to zero temperature.From the numerical observation for the coupling dependence of the phase diagram,we find that the coupling between the two gauge fields plays a crucial role in the formation of the dome.We also analytically calculate the DC conductivity of the normal phase of the system in the momentum dissipation and obtain resistivity which is proportional to the temperature.The AC conductivity is calculated numerically.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12174067 and 11804223)。
文摘We construct a three-dimensional topological superconductor Bogoliubov–de Gennes(BdG)Hamiltonian with the normal state being a three-dimensional topological insulator.By introducing inter-orbital spin-triplet pairings term△3,there are topological Majorana nodes in the bulk and they are connected by Majorana Fermi arcs on the surface,similar to the case of Weyl semimetal.Furthermore,by adding an inversion-breaking term to the normal state,momentum-independent pairing terms with different parities can coexist in the Bd G Hamiltonian,which creates more Majorana modes similar to Andreev bound states and a richer phase diagram.
基金The research was financially sponsored by the Major Scientific Research Planning Project of Colleges and Universities in Anhui Province(Grant No.2023AH040147)the National Natural Science Foundation of China(Grant No.52074093)the Outstanding Youth Scientific Research Project of Colleges and Universities in Anhui Province(Grant No.2022AH030044).
文摘Metallurgical dust(MD)was used as raw material to prepare rare earth Ce-doped Fe-based catalysts.The results show that the Ce_(0.1)/AMD-300℃catalyst prepared from acid-modified diatomite(AMD)with mCe/mMD=0.1(m_(Ce)and m_(MD)are the mass of Ce and MD,respectively)after being roasted at 300℃can reach 99%NO_(x)removal rate in the wide temperature range of 230–430℃and exhibits excellent So_(2)and H_(2)o resistance.The MD effectively removes alkali metal elements by the modification process,increases the specific surface area and optimizes the pore structure of MD.The doping of Ce element makes Fe-based catalysts have more surface adsorbed oxygen O_(α)and a higher Ce^(3+)/Ce^(4+)ratio.Through ammonia temperature-programmed desorption and hydrogen temperature-programmed reduction,it was found that the strong interaction between cerium and iron promotes the formation of more oxygen cavities in the catalyst,thereby generating more active and easily reducible oxygen species and promoting the transformation of Brønsted acid site to Lewis acid site.The research results provide a theoretical basis for the preparation of efficient and inexpensive Fe-based catalysts from MD.
