We report the thickness dependence of critical current density （Jc） in YBa2Cu3O7-x （YBCO） films with BaZrO3 （BZO） and Y2O3 additions grown on single crystal LaAlO3 substrates by metalorganic deposition using tri...We report the thickness dependence of critical current density （Jc） in YBa2Cu3O7-x （YBCO） films with BaZrO3 （BZO） and Y2O3 additions grown on single crystal LaAlO3 substrates by metalorganic deposition using trifluoroacetates （TFA-MOD）. Comparing with pttre YBCO films, the Jc of BZO/Y2O3-doped YBCO films was significantly enhanced. It was also found that with the increase of the thickness of YBCO film from 0.25 μm to 1.5 μm, the Ic of BZO/Y2O3-doped YBCO film increased from 130 A/cm to 250 A/cm and yet Jc of YBCO film decreased from 6.5 MA/cm2 to 2.5 M A/cm2. The thick BZO/Y2O3-doped MOD-YBCO film showed lower Jc, which is mainly attributed to the formation of a-axis grains and pores.展开更多
To simulate the effects of burnable poison doping in nuclear fuel UO2,Er2O3(or Gd2O3)-doped CeO2 pellets were prepared. Changes in lattice constant and atomic disordering for CeO2 due to the Er2O3 and Gd2O3 doping wer...To simulate the effects of burnable poison doping in nuclear fuel UO2,Er2O3(or Gd2O3)-doped CeO2 pellets were prepared. Changes in lattice constant and atomic disordering for CeO2 due to the Er2O3 and Gd2O3 doping were measured by means of XRD and XAFS. By the Er2O3 doping,the lattice constant decreased,and a disordering of lattice structure was induced in the samples. The doping with Er2O3 also induced the disordering of atomic arrangement around Er atoms,which was observed through the change in XAFS spectra. In contrast,the effect of Gd2O3 doping was smaller than that of Er2O3 doping. The result was discussed in terms of ionic size of dopants in CeO2 crystal.展开更多
Mg PSZ ceramics doped with Y 2O 3 and CeO 2 was prepared using traditional processing method. The fine grain PSZ ceramics( d c10 μm) sintered at low temperature(1550 ℃) was obtained by means of composition ...Mg PSZ ceramics doped with Y 2O 3 and CeO 2 was prepared using traditional processing method. The fine grain PSZ ceramics( d c10 μm) sintered at low temperature(1550 ℃) was obtained by means of composition design. The effects of co stabilization of Y 2O 3, CeO 2 and annealing at 1100 ℃ on material composition, microstructure and mechanical properties were studied. The results show that Y 2O 3 and CeO 2 during annealing at 1100 ℃ can inhibit subeutectoid decomposition reaction effectively, and optimize nucleation and growth of t ZrO 2 precipitates in c ZrO 2 matrix phase. The materials show transgranular and intergranular fracture characteristics, and exhibit better mechanical properties owing to the cooperative effect of stress induced transformation toughening and microcrack toughening.展开更多
The In 2 O 3 : W (IWO) films with different W content were deposited on glass substrate using direct current sputtering method. The structure, surface morphology, and optical and electrical properties were investigate...The In 2 O 3 : W (IWO) films with different W content were deposited on glass substrate using direct current sputtering method. The structure, surface morphology, and optical and electrical properties were investigated. Results showed that both the carrier concentration and carrier mobility were increased with the doping of W. The IWO film with the lowest resistivity of 1.0×10 3 cm, highest carrier mobilityof 43.7 cm 2 V 1 s 1 and carrier concentration of 1.4×10 20 cm 3 was obtained at the content of 2.8 wt.%. The average optical transmittance from 300 nm to 900 nm reached 87.6%.展开更多
The Mn doping effects on the gate-tunable transport properties of topological Dirac semimetal Cd3As2 films have been investigated.Mn-doped Cd3As2 films are directly grown on GaAs(111)B substrates by molecular-beam epi...The Mn doping effects on the gate-tunable transport properties of topological Dirac semimetal Cd3As2 films have been investigated.Mn-doped Cd3As2 films are directly grown on GaAs(111)B substrates by molecular-beam epitaxy,during which the single crystal phase can be obtained with Mn concentration less than 2%.Shubnikov-de Haas oscillation and quantum Hall effect are observed at low temperatures,and electrons are found to be the dominant carrier in the whole temperature range.Higher Mn content results in smaller lattice constant,lower electron mobility and larger effective band gap,while the carrier density seems to be unaffected by Mn-doping.Gating experiments show that Shubnikov-de Haas oscillation and quantum Hall effect are slightly modulated by electric field,which can be explained by the variation of electron density.Our results provide useful information for understanding the magnetic element doping effects on the transport properties of Cd3As2 films.展开更多
Ag- and Sn-doped In2S3 thin films were deposited on glass substrates using the thermal evaporation technique. The doping was realized by thermal diffusion. The influences of Ag and Sn impurities on the electrical, str...Ag- and Sn-doped In2S3 thin films were deposited on glass substrates using the thermal evaporation technique. The doping was realized by thermal diffusion. The influences of Ag and Sn impurities on the electrical, structural, morphological, and optical properties of the In2S3 films were investigated. In all deposited samples, the x-ray diffraction spectra revealed the formation of cubic In2S3 phase. A significant increase in the crystallite size was observed after Ag doping,while the doping of Sn slightly decreased the crystallite size. The x-ray photoelectron spectroscopy verified the diffusion of Ag and Sn into the In2S3 films after annealing. The optical study illustrated that Ag doping resulted in a reduction of the optical band gap while Sn doping led to a widening of the gap. Optical properties were investigated to determine the optical constants. Besides, it was found that the resistivity decreases significantly either after Ag or Sn incorporation. The study demonstrates that the Sn-doped In2S3 thin films are more suitable for buffer layer application in solar cells than the Ag-doped In2S3 thin films.展开更多
Thermally stable Zr4+, Al3+, and Si4+ cations were incorporated into the lattice of CeO2 nano‐rods (i.e., CeO2‐NR) in order to improve the specific surface area. The undoped and Zr4+, Al3+, and Si4+ doped nano‐rods...Thermally stable Zr4+, Al3+, and Si4+ cations were incorporated into the lattice of CeO2 nano‐rods (i.e., CeO2‐NR) in order to improve the specific surface area. The undoped and Zr4+, Al3+, and Si4+ doped nano‐rods were used as supports to prepare MnOx/CeO2‐NR, MnOx/CZ‐NR, MnOx/CA‐NR, and MnOx/CS‐NR catalysts, respectively. The prepared supports and catalysts were comprehensively characterized by transmission electron microscopy (TEM), high‐resolution TEM, X‐ray diffraction, Raman and N2‐physisorption analyses, hydrogen temperature‐programmed reduction, ammonia temperature‐programmed desorption, in situ diffuse reflectance infrared Fourier‐transform spectroscopic analysis of the NH3 adsorption, and X‐ray photoelectron spectroscopy. Moreover, the catalytic performance and H2O+SO2 tolerance of these samples were evaluated through NH3‐selective catalytic reduction (NH3‐SCR) in the absence or presence of H2O and SO2. The obtained results show that the MnOx/CS‐NR catalyst exhibits the highest NOx conversion and the lowest N2O concentration, which result from the largest number of oxygen vacancies and acid sites, the highest Mn4+ content, and the lowest redox ability. The MnOx/CS‐NR catalyst also presents excellent resistance to H2O and SO2. All of these phenomena suggest that Si4+ is the optimal dopant for the MnOx/CeO2‐NR catalyst.展开更多
Sb_(2)Te_(3)-based thermoelectric(TE)thin-film generators are an attractive option for wearable electronics.Band engineering can effectively modulate TE performance.However,modulating the band structure of Sb_(2)Te_(3...Sb_(2)Te_(3)-based thermoelectric(TE)thin-film generators are an attractive option for wearable electronics.Band engineering can effectively modulate TE performance.However,modulating the band structure of Sb_(2)Te_(3)thin film remains a challenging task.In this work,titanium(Ti)doping effectively modifies the electronic band structure in Sb_(2)Te_(3),optimizing both carrier transport and phonon transport performance.Ti-doping optimizes carrier concentration and resulting in an increase in electrical conductivity from 1420.0 S/cm to 1694.8 S/cm at 300 K.Additionally,Ti doping modulates the balance between the effective mass of charge carriers and carrier concentration,increasing Seebeck coefficient from 106.0μV/K to 114.8μV/K.Both enhancements lead to a peak power factor of 20.9μW·cm^(−1)·K^(−2).Moreover,Ti-induced vibrational modes have reduced the lattice thermal conductivity from 0.62 W·m^(−1)·K^(−1)to 0.22 W·m^(−1)·K^(−1),improving zT from 0.33 to 0.52 at 300 K.The films exhibit excellent flexibility,with an ultralow resistance change ratio(ΔR/R_(0))of less than 7%after 1000 cycles at a 6 mm bending radius.The device achieves a maximum output power of 178.8 nW with a temperature gradient of 30 K in agreement with the finite element analysis,indicating significant potential for wearable electronics.展开更多
Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg va...Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg vacancies easily leads to deterioration of electrical properties,especially for p-type Mg_(3)Bi_(2) flm.And the optimization of thermal conductivity of the Mg_(3)Bi_(2)-based flms is barely investigated.In this work,we demonstrate the improved thermoelectric performances of p-type Mg_(3)Bi_(2) through Ag doping by magnetron sputtering.This doping successfully reduces the hole concentration and broadens the band gap of Mg_(3)Bi_(2),thus resulting in a peak power factor of 442μW m^(−1) K^(−2) at 525 K.At the same time,Ag doping-induced fuctuations in mass and microscopic strain efectively enhanced the phonon scattering to reduce the lattice thermal conductivity.Consequently,a maximum thermoelectric fgure of merit of 0.22 is achieved at 525 K.Its near-roomtemperature thermoelectric performances demonstrate superior performance compared to many Mg_(3)Bi_(2)-based flms.To further evaluate its potential for thermoelectric power generation,we fabricated a thermoelectric device using Ag-doped Mg_(3)Bi_(2) flms,which achieved a power density of 864μW cm^(⁻2) at 35 K temperature diference.This study presents an efective strategy for the advancement of Mg_(3)Bi_(2)-based flms for application in micro-thermoelectric devices.展开更多
采用磁控溅射法制备不同含量Er掺杂Sb_(2)Te_(3)硫系相变存储薄膜,并利用原子力显微镜、X射线衍射仪、X射线光电子能谱仪、分光光度计、红外椭圆偏振仪等对其形貌、结构、电学性能、光学性能等进行表征分析.结果表明:Er掺杂可以有效抑制...采用磁控溅射法制备不同含量Er掺杂Sb_(2)Te_(3)硫系相变存储薄膜,并利用原子力显微镜、X射线衍射仪、X射线光电子能谱仪、分光光度计、红外椭圆偏振仪等对其形貌、结构、电学性能、光学性能等进行表征分析.结果表明:Er掺杂可以有效抑制Sb_(2)Te_(3)结晶生长、减小晶粒尺寸,从而显著增加结晶温度、降低电阻漂移系数(从0.01590降至0.00241),提升该相变存储薄膜整体的非晶态热稳定性.此外,随着Er掺杂含量的增加,Sb_(2)Te_(3)薄膜的短波截止吸收边出现蓝移,其光学带隙从1.40 e V分别提升至1.76 e V和1.94 e V,同时其红外波段的折射率明显降低.X射线衍射数据证实:Er掺杂会细化晶粒,引起Sb_(2)Te_(3)结晶相发生晶格畸变;X射线光电子能谱分析发现:相变性能提升的内在原因是高含量Er掺杂引起高结合能的Er-Te成键,表明Er掺杂有助于提高Sb_(2)Te_(3)相变材料在光电存储器件中的数据存储可靠性.这可为相变存储器用于大规模神经形态计算的下一代存算一体技术提供材料支撑.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51272250)the National Basic Research Program of China(Grant No.2011CBA00105)+1 种基金the National High Technology Research and Development Program of China(Grant No.2014AA032702)the Beijing Natural Science Foundation,China(Grant No.2152035)
文摘We report the thickness dependence of critical current density （Jc） in YBa2Cu3O7-x （YBCO） films with BaZrO3 （BZO） and Y2O3 additions grown on single crystal LaAlO3 substrates by metalorganic deposition using trifluoroacetates （TFA-MOD）. Comparing with pttre YBCO films, the Jc of BZO/Y2O3-doped YBCO films was significantly enhanced. It was also found that with the increase of the thickness of YBCO film from 0.25 μm to 1.5 μm, the Ic of BZO/Y2O3-doped YBCO film increased from 130 A/cm to 250 A/cm and yet Jc of YBCO film decreased from 6.5 MA/cm2 to 2.5 M A/cm2. The thick BZO/Y2O3-doped MOD-YBCO film showed lower Jc, which is mainly attributed to the formation of a-axis grains and pores.
基金Project supported by Japan Society for the Promotion of Science (JSPS) Research (Grant-in-aid for Scientific Research B No. 21360469)the Osaka Nuclear Science Association (ONSA),the XAFS Measurements at KEK-PF were Performed with the Approval of KEK (2009G536)
文摘To simulate the effects of burnable poison doping in nuclear fuel UO2,Er2O3(or Gd2O3)-doped CeO2 pellets were prepared. Changes in lattice constant and atomic disordering for CeO2 due to the Er2O3 and Gd2O3 doping were measured by means of XRD and XAFS. By the Er2O3 doping,the lattice constant decreased,and a disordering of lattice structure was induced in the samples. The doping with Er2O3 also induced the disordering of atomic arrangement around Er atoms,which was observed through the change in XAFS spectra. In contrast,the effect of Gd2O3 doping was smaller than that of Er2O3 doping. The result was discussed in terms of ionic size of dopants in CeO2 crystal.
文摘Mg PSZ ceramics doped with Y 2O 3 and CeO 2 was prepared using traditional processing method. The fine grain PSZ ceramics( d c10 μm) sintered at low temperature(1550 ℃) was obtained by means of composition design. The effects of co stabilization of Y 2O 3, CeO 2 and annealing at 1100 ℃ on material composition, microstructure and mechanical properties were studied. The results show that Y 2O 3 and CeO 2 during annealing at 1100 ℃ can inhibit subeutectoid decomposition reaction effectively, and optimize nucleation and growth of t ZrO 2 precipitates in c ZrO 2 matrix phase. The materials show transgranular and intergranular fracture characteristics, and exhibit better mechanical properties owing to the cooperative effect of stress induced transformation toughening and microcrack toughening.
基金financially supported by the National Natural Science Foundation of China (No. 50902006)the National High Technology Development 863 Program of China (No. 2009AA03Z428)National Student Innovative Experiment Plan
文摘The In 2 O 3 : W (IWO) films with different W content were deposited on glass substrate using direct current sputtering method. The structure, surface morphology, and optical and electrical properties were investigated. Results showed that both the carrier concentration and carrier mobility were increased with the doping of W. The IWO film with the lowest resistivity of 1.0×10 3 cm, highest carrier mobilityof 43.7 cm 2 V 1 s 1 and carrier concentration of 1.4×10 20 cm 3 was obtained at the content of 2.8 wt.%. The average optical transmittance from 300 nm to 900 nm reached 87.6%.
基金supported by NSFC(Grants Nos.U1632264 and 11704374)the the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB44000000 and QYZDY-SSW-JSC015)。
文摘The Mn doping effects on the gate-tunable transport properties of topological Dirac semimetal Cd3As2 films have been investigated.Mn-doped Cd3As2 films are directly grown on GaAs(111)B substrates by molecular-beam epitaxy,during which the single crystal phase can be obtained with Mn concentration less than 2%.Shubnikov-de Haas oscillation and quantum Hall effect are observed at low temperatures,and electrons are found to be the dominant carrier in the whole temperature range.Higher Mn content results in smaller lattice constant,lower electron mobility and larger effective band gap,while the carrier density seems to be unaffected by Mn-doping.Gating experiments show that Shubnikov-de Haas oscillation and quantum Hall effect are slightly modulated by electric field,which can be explained by the variation of electron density.Our results provide useful information for understanding the magnetic element doping effects on the transport properties of Cd3As2 films.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61076063,61340051,and 61306120)the Natural Science Foundation of Fujian Province,China(Grant No.2014J05073)
文摘Ag- and Sn-doped In2S3 thin films were deposited on glass substrates using the thermal evaporation technique. The doping was realized by thermal diffusion. The influences of Ag and Sn impurities on the electrical, structural, morphological, and optical properties of the In2S3 films were investigated. In all deposited samples, the x-ray diffraction spectra revealed the formation of cubic In2S3 phase. A significant increase in the crystallite size was observed after Ag doping,while the doping of Sn slightly decreased the crystallite size. The x-ray photoelectron spectroscopy verified the diffusion of Ag and Sn into the In2S3 films after annealing. The optical study illustrated that Ag doping resulted in a reduction of the optical band gap while Sn doping led to a widening of the gap. Optical properties were investigated to determine the optical constants. Besides, it was found that the resistivity decreases significantly either after Ag or Sn incorporation. The study demonstrates that the Sn-doped In2S3 thin films are more suitable for buffer layer application in solar cells than the Ag-doped In2S3 thin films.
基金supported by National Natural Science Foundation of China (21876168, 21507130)Youth Innovation Promotion Association of CAS (2019376)the Chongqing Science & Technology Commission (cstc2016jcyjA0070, cstckjcxljrc13)~~
文摘Thermally stable Zr4+, Al3+, and Si4+ cations were incorporated into the lattice of CeO2 nano‐rods (i.e., CeO2‐NR) in order to improve the specific surface area. The undoped and Zr4+, Al3+, and Si4+ doped nano‐rods were used as supports to prepare MnOx/CeO2‐NR, MnOx/CZ‐NR, MnOx/CA‐NR, and MnOx/CS‐NR catalysts, respectively. The prepared supports and catalysts were comprehensively characterized by transmission electron microscopy (TEM), high‐resolution TEM, X‐ray diffraction, Raman and N2‐physisorption analyses, hydrogen temperature‐programmed reduction, ammonia temperature‐programmed desorption, in situ diffuse reflectance infrared Fourier‐transform spectroscopic analysis of the NH3 adsorption, and X‐ray photoelectron spectroscopy. Moreover, the catalytic performance and H2O+SO2 tolerance of these samples were evaluated through NH3‐selective catalytic reduction (NH3‐SCR) in the absence or presence of H2O and SO2. The obtained results show that the MnOx/CS‐NR catalyst exhibits the highest NOx conversion and the lowest N2O concentration, which result from the largest number of oxygen vacancies and acid sites, the highest Mn4+ content, and the lowest redox ability. The MnOx/CS‐NR catalyst also presents excellent resistance to H2O and SO2. All of these phenomena suggest that Si4+ is the optimal dopant for the MnOx/CeO2‐NR catalyst.
基金supported by the National Natural Science Foundation of China(62274112)the National Natural Science Foundation of Guangdong province of China(2024B1515020119 and 2022A1515010929)+3 种基金the Science and Technology Plan Project of Shenzhen(JCYJ20220531103601003)Natural Science Foundation of Shandong Province(Nos.ZR2023ME001)the China Postdoctoral Science Foundation(Nos.2023M732609)Doctoral Research Initiation Fund of Weifang University(Nos.2023BS01).
文摘Sb_(2)Te_(3)-based thermoelectric(TE)thin-film generators are an attractive option for wearable electronics.Band engineering can effectively modulate TE performance.However,modulating the band structure of Sb_(2)Te_(3)thin film remains a challenging task.In this work,titanium(Ti)doping effectively modifies the electronic band structure in Sb_(2)Te_(3),optimizing both carrier transport and phonon transport performance.Ti-doping optimizes carrier concentration and resulting in an increase in electrical conductivity from 1420.0 S/cm to 1694.8 S/cm at 300 K.Additionally,Ti doping modulates the balance between the effective mass of charge carriers and carrier concentration,increasing Seebeck coefficient from 106.0μV/K to 114.8μV/K.Both enhancements lead to a peak power factor of 20.9μW·cm^(−1)·K^(−2).Moreover,Ti-induced vibrational modes have reduced the lattice thermal conductivity from 0.62 W·m^(−1)·K^(−1)to 0.22 W·m^(−1)·K^(−1),improving zT from 0.33 to 0.52 at 300 K.The films exhibit excellent flexibility,with an ultralow resistance change ratio(ΔR/R_(0))of less than 7%after 1000 cycles at a 6 mm bending radius.The device achieves a maximum output power of 178.8 nW with a temperature gradient of 30 K in agreement with the finite element analysis,indicating significant potential for wearable electronics.
基金supported by the National Natural Science Foundation of China(Nos.52073290 and 51927803)the Science Fund for Distinguished Young Scholars of Liaoning Province(No.2023JH6/100500004)the Shenyang Science and Technology Plan Project(No.23-407-3-23).
文摘Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg vacancies easily leads to deterioration of electrical properties,especially for p-type Mg_(3)Bi_(2) flm.And the optimization of thermal conductivity of the Mg_(3)Bi_(2)-based flms is barely investigated.In this work,we demonstrate the improved thermoelectric performances of p-type Mg_(3)Bi_(2) through Ag doping by magnetron sputtering.This doping successfully reduces the hole concentration and broadens the band gap of Mg_(3)Bi_(2),thus resulting in a peak power factor of 442μW m^(−1) K^(−2) at 525 K.At the same time,Ag doping-induced fuctuations in mass and microscopic strain efectively enhanced the phonon scattering to reduce the lattice thermal conductivity.Consequently,a maximum thermoelectric fgure of merit of 0.22 is achieved at 525 K.Its near-roomtemperature thermoelectric performances demonstrate superior performance compared to many Mg_(3)Bi_(2)-based flms.To further evaluate its potential for thermoelectric power generation,we fabricated a thermoelectric device using Ag-doped Mg_(3)Bi_(2) flms,which achieved a power density of 864μW cm^(⁻2) at 35 K temperature diference.This study presents an efective strategy for the advancement of Mg_(3)Bi_(2)-based flms for application in micro-thermoelectric devices.
文摘采用磁控溅射法制备不同含量Er掺杂Sb_(2)Te_(3)硫系相变存储薄膜,并利用原子力显微镜、X射线衍射仪、X射线光电子能谱仪、分光光度计、红外椭圆偏振仪等对其形貌、结构、电学性能、光学性能等进行表征分析.结果表明:Er掺杂可以有效抑制Sb_(2)Te_(3)结晶生长、减小晶粒尺寸,从而显著增加结晶温度、降低电阻漂移系数(从0.01590降至0.00241),提升该相变存储薄膜整体的非晶态热稳定性.此外,随着Er掺杂含量的增加,Sb_(2)Te_(3)薄膜的短波截止吸收边出现蓝移,其光学带隙从1.40 e V分别提升至1.76 e V和1.94 e V,同时其红外波段的折射率明显降低.X射线衍射数据证实:Er掺杂会细化晶粒,引起Sb_(2)Te_(3)结晶相发生晶格畸变;X射线光电子能谱分析发现:相变性能提升的内在原因是高含量Er掺杂引起高结合能的Er-Te成键,表明Er掺杂有助于提高Sb_(2)Te_(3)相变材料在光电存储器件中的数据存储可靠性.这可为相变存储器用于大规模神经形态计算的下一代存算一体技术提供材料支撑.
