本文采用电弧离子镀(Arc ion plating,AIP)和高功率脉冲磁控溅射(High power impulse magnetron sputtering,HiPIMS)复合方法,通过调控HiPIMS占空比在M2高速钢基体和单晶硅片上沉积TiZrN/TiN纳米多层膜,探究HiPIMS占空比对TiZrN/TiN纳...本文采用电弧离子镀(Arc ion plating,AIP)和高功率脉冲磁控溅射(High power impulse magnetron sputtering,HiPIMS)复合方法,通过调控HiPIMS占空比在M2高速钢基体和单晶硅片上沉积TiZrN/TiN纳米多层膜,探究HiPIMS占空比对TiZrN/TiN纳米多层膜微观结构和性能的影响规律。结果表明:随着HiPIMS占空比的增加,TiZrN/TiN纳米多层膜表面大颗粒数量呈先减少后增加趋势,同时薄膜厚度呈先减小后增大趋势。随着HiPIMS占空比从2%增加10%,TiZrN/TiN纳米多层膜择优取向从(111)晶面转变为(220)晶面,膜基结合力等级均为HF1级,硬度均在33 GPa以上,稳定摩擦因数在0.79左右。当HiPIMS占空比为2%时,TiZrN/TiN纳米多层膜的磨损率达到最小,为1.73×10^(-8) mm^(3)/(N·mm),薄膜的耐磨损性能最好。当HiPIMS占空比为6%时,TiZrN/TiN纳米多层膜的硬度和弹性模量分别增加到43.73GPa和362.98 GPa,自腐蚀电位可达到-0.39 V(vs SCE),自腐蚀电流密度为0.731μA/cm^(2),薄膜耐腐蚀性能最强,腐蚀速率较低。综合对比可知,HiPIMS占空比为6%,是TiZrN/TiN纳米多层膜制备的最佳工艺参数。展开更多
The CrN and Cr-Al-Si-N films were deposited on Si wafer and SUS 304 substrates by a hybrid coating system with high power impulse magnetron sputtering (HIPIMS) and a DC pulse sputtering using Cr and AlSi targets under...The CrN and Cr-Al-Si-N films were deposited on Si wafer and SUS 304 substrates by a hybrid coating system with high power impulse magnetron sputtering (HIPIMS) and a DC pulse sputtering using Cr and AlSi targets under N2/Ar atmosphere.By varying the sputtering current of the AlSi target in the range of 0-2.5 A,both the Al and Si contents in the films increased gradually from 0 to 19.1% and 11.1% (mole fraction),respectively.The influences of the AlSi cathode DC pulse current on the microstructure,phase constituents,mechanical properties,and oxidation behaviors of the Cr-Al-Si-N films were investigated systematically.The results indicate that the as-deposited Cr-Al-Si-N films possess the typical nanocomposite structure,namely the face centered cubic (Cr,Al)N nano-crystallites are embedded in the amorphous Si3N4 matrix.With increasing the Al and Si contents,the hardness of the film first increases from 20.8 GPa for the CrN film to the peak value of 29.4 GPa for the Cr0.23Al0.14Si0.07 N film,and then decreases gradually.In the meanwhile,the Cr0.23Al0.14Si0.07N film also possesses excellent high-temperature oxidation resistance that is much better than that of the CrN film at 900 or 1000 °C.展开更多
The Cr–Si–N coatings were prepared by combining system of high-power impulse magnetron sputtering and pulsed DC magnetron sputtering. The Si content in the coating was adjusted by changing the sputtering power of th...The Cr–Si–N coatings were prepared by combining system of high-power impulse magnetron sputtering and pulsed DC magnetron sputtering. The Si content in the coating was adjusted by changing the sputtering power of the Si target.By virtue of electron-probe microanalysis, X-ray diffraction analysis and scanning electron microscopy, the influence of the Si content on the coating composition, phase constituents, deposition rate, surface morphology and microstructure was investigated systematically. In addition, the change rules of micro-hardness, internal stress, adhesion, friction coefficient and wear rate with increasing Si content were also obtained. In this work, the precipitation of silicon in the coating was found.With increasing Si content, the coating microstructure gradually evolved from continuous columnar to discontinuous columnar and quasi-equiaxed crystals; accordingly, the coating inner stress first declined sharply and then kept almost constant. Both the coating hardness and the friction coefficient have the same change tendency with the increase of the Si content, namely increasing at first and then decreasing. The Cr–Si–N coating presented the highest hardness and average friction coefficient for an Si content of about 9.7 at.%, but the wear resistance decreased slightly due to the high brittleness.The above phenomenon was attributed to a microstructural evolution of the Cr–Si–N coatings induced by the silicon addition.展开更多
Perovskite solar cells(PSCs) have become a hot topic in the field of renewable energy due to their excellent power conversion efficiency and potential for low-cost manufacturing. The hole transport layer(HTL), as a ke...Perovskite solar cells(PSCs) have become a hot topic in the field of renewable energy due to their excellent power conversion efficiency and potential for low-cost manufacturing. The hole transport layer(HTL), as a key component of PSCs,plays a crucial role in the cell's overall performance. Magnetron sputtering NiO_(x) has attracted widespread attention due to its high carrier mobility, excellent stability, and suitability for large-scale production. Herein, an insightful summary of the recent progress of magnetron sputtering NiO_(x) as the HTL of PSCs is presented to promote its further development. This review summarized the basic properties of magnetron sputtering NiO_(x) thin film, the key parameters affecting the optoelectronic properties of NiO_(x) thin films during the magnetron-sputtering process, and the performance of the corresponding PSCs. Special attention was paid to the interfacial issues between NiO_(x) and perovskites, and the modification strategies were systematically summarized. Finally, the challenges of sputtering NiO_(x) technology and the possible development opportunities were concluded and discussed.展开更多
By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering met...By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering method in pure argon and pure oxygen gas,respectively.The crystal structure,morphological characteristics,composition and optical properties of the obtained films were compared by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ultraviolet(UV)-visible spectrophotometer.The properties of the thin films deposited in different sputtering gases are quite different.For the films deposited in pure argon gas,it is a polycrystalline thin film with(200)preferred orientation,while the film deposited in pure oxygen has no preferred orientation.The grain size,molar ratio of Mg to Ni atoms and optical bandgap are larger for the films deposited in pure argon gas than those deposited in oxygen gas.展开更多
The discharge and plasma characteristics of Ag magnetron sputtering discharge operated near the electron series resonance(ESR)oscillation,which was excited using the driving frequency of 27.12 MHz,was investigated.The...The discharge and plasma characteristics of Ag magnetron sputtering discharge operated near the electron series resonance(ESR)oscillation,which was excited using the driving frequency of 27.12 MHz,was investigated.The imaginary part of impedance was found to undergo a transition from capacitive to inductive on varying radio-frequency(RF)power,and the conditions for the ESR excitation were satisfied.The current–voltage(I–V)characteristic of discharge showed that the lower discharge voltage with higher current was an important feature of RF magnetron sputtering operated near the ESR oscillation,which was caused by the small impedance Z originated from the mutual compensation between the sheath capacitive reactance and the plasma inductive reactance.The higher electron temperature,ion flux density and ion energy as well as the moderate electron density were obtained.The interaction of higher energy ions on substrate surface improved the crystallographic quality of Ag films.Therefore,the 27.12 MHz magnetron sputtering operated near the ESR oscillation has better deposition characteristics than that of commercial 13.56 MHz RF magnetron sputtering.展开更多
Silver is an elegant white precious metal,but it is easily oxidized by O3,SO2,and H2S in the air,turning yellow or dark,which affects its decorative effect.The existing silver coating,primarily prepared through the el...Silver is an elegant white precious metal,but it is easily oxidized by O3,SO2,and H2S in the air,turning yellow or dark,which affects its decorative effect.The existing silver coating,primarily prepared through the electroplating process,poses serious environmental pollution problems.It is necessary to seek new,green,and environmentally friendly coating processes while also enhancing the color palette of silver jewelry coatings.Titanium film layers were deposited on Ag925 and Ag999 surfaces using magnetron sputtering coating technology.The effects of sputtering time,substrate surface state,reaction gas type and time,and film thickness on the color of the film layers were studied,and the anti discoloration performance of the obtained film layers under the optimal process was tested.The experimental results show that when the sputtering time varies from 5 to 10 minutes,injecting argon,oxygen,and nitrogen into the coating chamber yields rich colors such as purple with a red tint,blue,yellow green,yellowish purple,and blue purple.The precise control of gas injection time has a significant impact on the color of the film layer.In terms of anti tarnish performance,the film showed good stability in the artificial sweat immersion test.From an environmental perspective,the magnetron sputtering titanium film process has no harmful gas or liquid emissions,which aligns with the sustainable development trend of the jewelry industry and holds great promise for application.This study has improved the visual effect and practical performance of the product,providing important theoretical basis and experimental data support for the application of environmentally friendly silver surface vacuum magnetron sputtering titanium thin film coating technology.展开更多
Ammonium dinitramide(ADN),as a high-energy oxidizer widely applied in the field of rocket and missile propellants,has a prominent issue of high hygroscopicity due to its strong polarity.The previous coating encapsulat...Ammonium dinitramide(ADN),as a high-energy oxidizer widely applied in the field of rocket and missile propellants,has a prominent issue of high hygroscopicity due to its strong polarity.The previous coating encapsulation methods have struggled to address the problems of uneven coating and polarity mismatch.This research innovatively introduces perfluorooctanoic acid(PFOA)as a polar transition intermediate layer.Utilizing the polarity of one end of it to adsorb on the surface of ADN through hydrogen bonds,the problem of polarity mismatch is effectively overcome.Meanwhile,the vibrational magnetron sputtering process has been first applied in the energetic field,with a special vibrating abutment enhancing ADN particle fluidity to solve coating non-uniformity,thus preparing prilled ADN@PFOA@PTFE core-dual-shell composites.Performance tests reveal that this composite material possesses excellent hydrophobic and anti-hygroscopic properties.When left at 25℃and 75%RH for 3 days,moisture absorption was reduced by more than 90%compared to pure ADN.Simultaneously,its thermal stability,heat release performance,and combustion performance have been improved.The research achievements optimize the storage conditions of ADN in the application of rocket and missile propellants,providing solid support and broad development prospects for technological innovation in military fields.展开更多
Ensuring high electrocatalytic performance simultaneously with low or even no precious-metal usage is still a big challenge for the development of electrocatalysts toward oxygen evolution reaction(OER)in anion exchang...Ensuring high electrocatalytic performance simultaneously with low or even no precious-metal usage is still a big challenge for the development of electrocatalysts toward oxygen evolution reaction(OER)in anion exchange membrane water electrolysis.Here,homogeneous high entropy oxide(HEO)film is in-situ fabricated on nickel foam(NF)substrate via magnetron sputtering technology without annealing process in air,which is composed of many spinel-structured(FeCoNiCrMo)_(3)O_(4) grains with an average particle size of 2.5 nm.The resulting HEO film(abbreviated as(FeCoNiCr-Mo)_(3)O_(4))exhibits a superior OER performance with a low OER overpotential of 216 mV at 10 mA cm^(–2) and steadily operates at 100 mA cm^(–2) for 200 h with a decay of only 272μV h^(–1),which is far better than that of commercial IrO_(2) catalyst(290 mV,1090μV h^(–1)).Tetramethylammonium cation(TMA^(+))probe experiment,activation energy analysis and theoretical calculations unveil that the OER on(FeCoNiCrMo)_(3)O_(4) follows an adsorbate evolution mechanism pathway,where the energy barrier of rate-determining step for OER on(FeCoNiCrMo)_(3)O_(4) is substantially lowered.Also,methanol molecular probe experiment suggests that a weakened ^(*)OH bonding on the(FeCoNiCrMo)_(3)O_(4) surface and a rapid deprotonation of ^(*)OH,further enhancing its OER performance.This work provides a feasible solution for designing efficient high entropy oxides electrocatalysts for OER,accelerating the practical process of water electrolysis for H2 production.展开更多
In the past few decades,ion engines have been widely used in deep-space propulsion and satellite station-keeping.The aim of extending the thruster lifetime is still one of the most important parts during the design st...In the past few decades,ion engines have been widely used in deep-space propulsion and satellite station-keeping.The aim of extending the thruster lifetime is still one of the most important parts during the design stage of ion engine.As one of the core components of ion engine,the grid assembly of ion optic systems may experience long-term ion sputtering in extreme electro-thermal environments,which will eventually lead to its structural and electron-backstreaming failures.In this paper,the current studies of the grid assembly erosion process are systematically analyzed from the aspects of sputtering damage process of grid materials,numerical simulations,and measurements of erosion characteristics of grid assembly.The advantages and disadvantages of various erosion prediction models are highlighted,and the key factors and processes affecting the prediction accuracy of grid assembly erosion patterns are analyzed.Three different types of experimental methods of grid assembly erosion patterns are compared.The analysis in this paper is of great importance for selecting the sputter-resistant grid materials,as well as establishing the erosion models and measurement methods to accurately determine the erosion rate and failure modes of grid assembly.Consequently,the working conditions and structure parameters of ion optic systems could be optimized based on erosion models to promote the ion engine lifetime.展开更多
Ta-doped SnO_(2)(TTO)is a suitable candidate to replace transparent conductive oxide(TCO)composed of expensive indium used for optoelectronics and silicon heterojunction solar cells fabricated below 200℃.However,TTO ...Ta-doped SnO_(2)(TTO)is a suitable candidate to replace transparent conductive oxide(TCO)composed of expensive indium used for optoelectronics and silicon heterojunction solar cells fabricated below 200℃.However,TTO films fabricated by sputtering at low temperature still demonstrate too high resistance and optical absorptance for application in industry.In this study,we investigate the influence of sputtering ambient on the optoelectrical properties of TTO films.The addition of hydrogen and oxygen to argon during sputtering leads to a large improvement in the optoelectrical properties of TTO films.The best TTO film has a low average absorptance of 1.9%and a low resistance of 3.8×10^(-3)Ω·cm with a high carrier density of 9.3×10^(19)cm^(-3)and mobility of 17.8 cm^(2)·V^(-1)·s^(-1).The micros tructural and compositional properties of TTO films were characterized using x-ray diffraction,x-ray photoelectron spectroscopy and UV-Vis spectrophotometry.A proper ratio of hydrogen to oxygen in the sputtering gas improves the crystallinity and the doping efficiency of Ta.Optical absorptance is also reduced with suppressed formation of Sn(Ⅱ)in the TTO films.Therefore,our findings exhibit remarkable potential for the industrial application of TTO as a low-cost TCO.展开更多
Atmospheric escape plays a critical role in shaping the long-term climate evolution of Mars.Among the various escape mechanisms,energetic neutral atoms(ENAs)generated through charge exchange between solar wind ions an...Atmospheric escape plays a critical role in shaping the long-term climate evolution of Mars.Among the various escape mechanisms,energetic neutral atoms(ENAs)generated through charge exchange between solar wind ions and exospheric neutrals serve as an important diagnostic for ion-neutral interactions and upper atmospheric loss.This study presents direct observations of hydrogen ENAs(H-ENAs)on the dayside of Mars by using the Mars Ion and Neutral Particle Analyzer(MINPA)onboard China’s Tianwen-1 orbiter.By analyzing H-ENA data during a coronal mass ejection and a stream interaction region from December 29,2021,to January 1,2022,and comparing these data with MAVEN/SWIA(Mars Atmosphere and Volatile EvolutioN/Solar Wind Ion Analyzer)solar wind measurements,we examine the temporal evolution of H-ENA flux and the associated sputtered escape of atmospheric constituents.The observed H-ENA velocity is consistent with upstream solar wind ions,and the H-ENA-to-ion intensity ratio is used to infer variations in exospheric density,revealing a delayed response to enhanced solar wind activity.Penetrating H-ENA intensities reach up to 5.3×10^(6)s^(−1) cm^(−2),with energy fluxes on the order of(0.5-8.1)×10^(−3) mW/m^(2).The estimated oxygen sputtered escape rate driven by penetrating H-ENAs ranges from 5.5×10^(23)s^(−1) to 5.2×10^(24)s^(−1),comparable to or exceeding previous estimates based on penetrating ions.The findings highlight the need for low-altitude H-ENA observations to better quantify their atmospheric interactions and refine our understanding of nonthermal escape processes at Mars.展开更多
基金supported by a 2-Year Research Grant of Pusan National University,Korea
文摘The CrN and Cr-Al-Si-N films were deposited on Si wafer and SUS 304 substrates by a hybrid coating system with high power impulse magnetron sputtering (HIPIMS) and a DC pulse sputtering using Cr and AlSi targets under N2/Ar atmosphere.By varying the sputtering current of the AlSi target in the range of 0-2.5 A,both the Al and Si contents in the films increased gradually from 0 to 19.1% and 11.1% (mole fraction),respectively.The influences of the AlSi cathode DC pulse current on the microstructure,phase constituents,mechanical properties,and oxidation behaviors of the Cr-Al-Si-N films were investigated systematically.The results indicate that the as-deposited Cr-Al-Si-N films possess the typical nanocomposite structure,namely the face centered cubic (Cr,Al)N nano-crystallites are embedded in the amorphous Si3N4 matrix.With increasing the Al and Si contents,the hardness of the film first increases from 20.8 GPa for the CrN film to the peak value of 29.4 GPa for the Cr0.23Al0.14Si0.07 N film,and then decreases gradually.In the meanwhile,the Cr0.23Al0.14Si0.07N film also possesses excellent high-temperature oxidation resistance that is much better than that of the CrN film at 900 or 1000 °C.
基金supported by the Global Frontier Program through the Global Frontier Hybrid Interface Materials(GFHIM)of the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT&Future Planning(No.2013M3A6B1078874)funded by the National Nature Science Foundation of China(No.51301181)+2 种基金the Tianjin Key Research Program of Application Foundation and Advanced Technology(No.15JCZDJC39700)the Tianjin Science and Technology correspondent project(No.16JCTPJC49500)the Innovation Team Training Plan of Tianjin Universities and colleges(No.TD12-5043)
文摘The Cr–Si–N coatings were prepared by combining system of high-power impulse magnetron sputtering and pulsed DC magnetron sputtering. The Si content in the coating was adjusted by changing the sputtering power of the Si target.By virtue of electron-probe microanalysis, X-ray diffraction analysis and scanning electron microscopy, the influence of the Si content on the coating composition, phase constituents, deposition rate, surface morphology and microstructure was investigated systematically. In addition, the change rules of micro-hardness, internal stress, adhesion, friction coefficient and wear rate with increasing Si content were also obtained. In this work, the precipitation of silicon in the coating was found.With increasing Si content, the coating microstructure gradually evolved from continuous columnar to discontinuous columnar and quasi-equiaxed crystals; accordingly, the coating inner stress first declined sharply and then kept almost constant. Both the coating hardness and the friction coefficient have the same change tendency with the increase of the Si content, namely increasing at first and then decreasing. The Cr–Si–N coating presented the highest hardness and average friction coefficient for an Si content of about 9.7 at.%, but the wear resistance decreased slightly due to the high brittleness.The above phenomenon was attributed to a microstructural evolution of the Cr–Si–N coatings induced by the silicon addition.
基金financially supported by the Natural Science Foundation of China (62288102, 22379067, T2441002, 6220514, and 5230226)the National Key Research and Development Program of China (2023YFB4204500)+1 种基金the Jiangsu Provincial Departments of Science and Technology (BE2022023, BK20220010, and BZ2023060)the Open Project Program of Wuhan National Laboratory for Optoelectronics (2021WNLOKF003)。
文摘Perovskite solar cells(PSCs) have become a hot topic in the field of renewable energy due to their excellent power conversion efficiency and potential for low-cost manufacturing. The hole transport layer(HTL), as a key component of PSCs,plays a crucial role in the cell's overall performance. Magnetron sputtering NiO_(x) has attracted widespread attention due to its high carrier mobility, excellent stability, and suitability for large-scale production. Herein, an insightful summary of the recent progress of magnetron sputtering NiO_(x) as the HTL of PSCs is presented to promote its further development. This review summarized the basic properties of magnetron sputtering NiO_(x) thin film, the key parameters affecting the optoelectronic properties of NiO_(x) thin films during the magnetron-sputtering process, and the performance of the corresponding PSCs. Special attention was paid to the interfacial issues between NiO_(x) and perovskites, and the modification strategies were systematically summarized. Finally, the challenges of sputtering NiO_(x) technology and the possible development opportunities were concluded and discussed.
基金supported by the Jilin Provincial Scientific and Technological Development Program(No.20220101036JC)。
文摘By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering method in pure argon and pure oxygen gas,respectively.The crystal structure,morphological characteristics,composition and optical properties of the obtained films were compared by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ultraviolet(UV)-visible spectrophotometer.The properties of the thin films deposited in different sputtering gases are quite different.For the films deposited in pure argon gas,it is a polycrystalline thin film with(200)preferred orientation,while the film deposited in pure oxygen has no preferred orientation.The grain size,molar ratio of Mg to Ni atoms and optical bandgap are larger for the films deposited in pure argon gas than those deposited in oxygen gas.
基金supported by National Natural Science Foundation of China (No.11275136)。
文摘The discharge and plasma characteristics of Ag magnetron sputtering discharge operated near the electron series resonance(ESR)oscillation,which was excited using the driving frequency of 27.12 MHz,was investigated.The imaginary part of impedance was found to undergo a transition from capacitive to inductive on varying radio-frequency(RF)power,and the conditions for the ESR excitation were satisfied.The current–voltage(I–V)characteristic of discharge showed that the lower discharge voltage with higher current was an important feature of RF magnetron sputtering operated near the ESR oscillation,which was caused by the small impedance Z originated from the mutual compensation between the sheath capacitive reactance and the plasma inductive reactance.The higher electron temperature,ion flux density and ion energy as well as the moderate electron density were obtained.The interaction of higher energy ions on substrate surface improved the crystallographic quality of Ag films.Therefore,the 27.12 MHz magnetron sputtering operated near the ESR oscillation has better deposition characteristics than that of commercial 13.56 MHz RF magnetron sputtering.
文摘Silver is an elegant white precious metal,but it is easily oxidized by O3,SO2,and H2S in the air,turning yellow or dark,which affects its decorative effect.The existing silver coating,primarily prepared through the electroplating process,poses serious environmental pollution problems.It is necessary to seek new,green,and environmentally friendly coating processes while also enhancing the color palette of silver jewelry coatings.Titanium film layers were deposited on Ag925 and Ag999 surfaces using magnetron sputtering coating technology.The effects of sputtering time,substrate surface state,reaction gas type and time,and film thickness on the color of the film layers were studied,and the anti discoloration performance of the obtained film layers under the optimal process was tested.The experimental results show that when the sputtering time varies from 5 to 10 minutes,injecting argon,oxygen,and nitrogen into the coating chamber yields rich colors such as purple with a red tint,blue,yellow green,yellowish purple,and blue purple.The precise control of gas injection time has a significant impact on the color of the film layer.In terms of anti tarnish performance,the film showed good stability in the artificial sweat immersion test.From an environmental perspective,the magnetron sputtering titanium film process has no harmful gas or liquid emissions,which aligns with the sustainable development trend of the jewelry industry and holds great promise for application.This study has improved the visual effect and practical performance of the product,providing important theoretical basis and experimental data support for the application of environmentally friendly silver surface vacuum magnetron sputtering titanium thin film coating technology.
基金funded by Open Research Fund Program of National Key Laboratory of Aerospace Chemical Power(NKLACP120241B04)National Natural Science Foundation of China Youth Science Foundation(12402450)。
文摘Ammonium dinitramide(ADN),as a high-energy oxidizer widely applied in the field of rocket and missile propellants,has a prominent issue of high hygroscopicity due to its strong polarity.The previous coating encapsulation methods have struggled to address the problems of uneven coating and polarity mismatch.This research innovatively introduces perfluorooctanoic acid(PFOA)as a polar transition intermediate layer.Utilizing the polarity of one end of it to adsorb on the surface of ADN through hydrogen bonds,the problem of polarity mismatch is effectively overcome.Meanwhile,the vibrational magnetron sputtering process has been first applied in the energetic field,with a special vibrating abutment enhancing ADN particle fluidity to solve coating non-uniformity,thus preparing prilled ADN@PFOA@PTFE core-dual-shell composites.Performance tests reveal that this composite material possesses excellent hydrophobic and anti-hygroscopic properties.When left at 25℃and 75%RH for 3 days,moisture absorption was reduced by more than 90%compared to pure ADN.Simultaneously,its thermal stability,heat release performance,and combustion performance have been improved.The research achievements optimize the storage conditions of ADN in the application of rocket and missile propellants,providing solid support and broad development prospects for technological innovation in military fields.
文摘Ensuring high electrocatalytic performance simultaneously with low or even no precious-metal usage is still a big challenge for the development of electrocatalysts toward oxygen evolution reaction(OER)in anion exchange membrane water electrolysis.Here,homogeneous high entropy oxide(HEO)film is in-situ fabricated on nickel foam(NF)substrate via magnetron sputtering technology without annealing process in air,which is composed of many spinel-structured(FeCoNiCrMo)_(3)O_(4) grains with an average particle size of 2.5 nm.The resulting HEO film(abbreviated as(FeCoNiCr-Mo)_(3)O_(4))exhibits a superior OER performance with a low OER overpotential of 216 mV at 10 mA cm^(–2) and steadily operates at 100 mA cm^(–2) for 200 h with a decay of only 272μV h^(–1),which is far better than that of commercial IrO_(2) catalyst(290 mV,1090μV h^(–1)).Tetramethylammonium cation(TMA^(+))probe experiment,activation energy analysis and theoretical calculations unveil that the OER on(FeCoNiCrMo)_(3)O_(4) follows an adsorbate evolution mechanism pathway,where the energy barrier of rate-determining step for OER on(FeCoNiCrMo)_(3)O_(4) is substantially lowered.Also,methanol molecular probe experiment suggests that a weakened ^(*)OH bonding on the(FeCoNiCrMo)_(3)O_(4) surface and a rapid deprotonation of ^(*)OH,further enhancing its OER performance.This work provides a feasible solution for designing efficient high entropy oxides electrocatalysts for OER,accelerating the practical process of water electrolysis for H2 production.
基金co-supported by the National Key R&D Program of China(No.2022YFB3403500)the National Natural Science Foundation of China(No.NSFC52202460)the China Postdoctoral Science Foundation(Nos.2021M690392,2021TQ0036,and 2023TQ0031)。
文摘In the past few decades,ion engines have been widely used in deep-space propulsion and satellite station-keeping.The aim of extending the thruster lifetime is still one of the most important parts during the design stage of ion engine.As one of the core components of ion engine,the grid assembly of ion optic systems may experience long-term ion sputtering in extreme electro-thermal environments,which will eventually lead to its structural and electron-backstreaming failures.In this paper,the current studies of the grid assembly erosion process are systematically analyzed from the aspects of sputtering damage process of grid materials,numerical simulations,and measurements of erosion characteristics of grid assembly.The advantages and disadvantages of various erosion prediction models are highlighted,and the key factors and processes affecting the prediction accuracy of grid assembly erosion patterns are analyzed.Three different types of experimental methods of grid assembly erosion patterns are compared.The analysis in this paper is of great importance for selecting the sputter-resistant grid materials,as well as establishing the erosion models and measurement methods to accurately determine the erosion rate and failure modes of grid assembly.Consequently,the working conditions and structure parameters of ion optic systems could be optimized based on erosion models to promote the ion engine lifetime.
基金Project supported by the Key-Area Research and Development Program of Guangdong Province,China(Grant No.2021B0101260001)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2019A1515110411)。
文摘Ta-doped SnO_(2)(TTO)is a suitable candidate to replace transparent conductive oxide(TCO)composed of expensive indium used for optoelectronics and silicon heterojunction solar cells fabricated below 200℃.However,TTO films fabricated by sputtering at low temperature still demonstrate too high resistance and optical absorptance for application in industry.In this study,we investigate the influence of sputtering ambient on the optoelectrical properties of TTO films.The addition of hydrogen and oxygen to argon during sputtering leads to a large improvement in the optoelectrical properties of TTO films.The best TTO film has a low average absorptance of 1.9%and a low resistance of 3.8×10^(-3)Ω·cm with a high carrier density of 9.3×10^(19)cm^(-3)and mobility of 17.8 cm^(2)·V^(-1)·s^(-1).The micros tructural and compositional properties of TTO films were characterized using x-ray diffraction,x-ray photoelectron spectroscopy and UV-Vis spectrophotometry.A proper ratio of hydrogen to oxygen in the sputtering gas improves the crystallinity and the doping efficiency of Ta.Optical absorptance is also reduced with suppressed formation of Sn(Ⅱ)in the TTO films.Therefore,our findings exhibit remarkable potential for the industrial application of TTO as a low-cost TCO.
基金supported by the National Natural Science Foundation of China (Grant Nos. 42188101, 42274211, 41974170, 42374184, 42122032, and 41974196)the Chinese Academy of Sciences (Grant Nos. QYZDJSSW-JSC028, XDA15052500, XDA17010301, and XDB41000000)+3 种基金the CNSA (Grant No. D050103)the Specialized Research Fund for State Key Laboratories of Chinathe Specialized Research Fund for Laboratory of Geospace Environment of the University of Science and Technology of Chinasupported by the International Space Science Institute (ISSI) in Bern and Beijing through the ISSI/ISSI-BJ International Team Project titled “Understanding the Mars Space Environment Through Multi-Spacecraft Measurements” (ISSI Team Project No. 23-582 and ISSI-BJ Team Project No. 58)
文摘Atmospheric escape plays a critical role in shaping the long-term climate evolution of Mars.Among the various escape mechanisms,energetic neutral atoms(ENAs)generated through charge exchange between solar wind ions and exospheric neutrals serve as an important diagnostic for ion-neutral interactions and upper atmospheric loss.This study presents direct observations of hydrogen ENAs(H-ENAs)on the dayside of Mars by using the Mars Ion and Neutral Particle Analyzer(MINPA)onboard China’s Tianwen-1 orbiter.By analyzing H-ENA data during a coronal mass ejection and a stream interaction region from December 29,2021,to January 1,2022,and comparing these data with MAVEN/SWIA(Mars Atmosphere and Volatile EvolutioN/Solar Wind Ion Analyzer)solar wind measurements,we examine the temporal evolution of H-ENA flux and the associated sputtered escape of atmospheric constituents.The observed H-ENA velocity is consistent with upstream solar wind ions,and the H-ENA-to-ion intensity ratio is used to infer variations in exospheric density,revealing a delayed response to enhanced solar wind activity.Penetrating H-ENA intensities reach up to 5.3×10^(6)s^(−1) cm^(−2),with energy fluxes on the order of(0.5-8.1)×10^(−3) mW/m^(2).The estimated oxygen sputtered escape rate driven by penetrating H-ENAs ranges from 5.5×10^(23)s^(−1) to 5.2×10^(24)s^(−1),comparable to or exceeding previous estimates based on penetrating ions.The findings highlight the need for low-altitude H-ENA observations to better quantify their atmospheric interactions and refine our understanding of nonthermal escape processes at Mars.
