High quality Nb films were successfully prepared on both flexible polyimide(PI)and rigid Al2O3substrates and their transport properties were systematically studied at various applied currents,external magnetic fields,...High quality Nb films were successfully prepared on both flexible polyimide(PI)and rigid Al2O3substrates and their transport properties were systematically studied at various applied currents,external magnetic fields,and sample orientations.It is found that a curved Nb/PI film exhibits quite different superconducting transition and vortex dynamics compared to the flat Nb/Al2O3film.For the curved Nb/PI film,smooth superconducting transitions were obtained at low currents,while unexpected cascade structures were revealed in theρ(T)curves at high currents.We attribute this phenomenon to the gradient distribution of vortex density together with a variation of superconductivity along the curved film.In addition,reentrant superconductivity was induced in the curved Nb/PI thin film by properly choosing the measurement conditions.We attribute this effect to the vortex pinning from both in-plane vortices and out-of-plane vortices.This work reveals the complex transport properties of curved superconducting thin films,providing important insights for further theoretical investigations and practical developments of flexible superconductors.展开更多
Ta As,the first experimentally discovered Weyl semimetal material,has attracted a lot of attention due to its high carrier mobility,high anisotropy,nonmagnetic properties and strong interaction with light.These make i...Ta As,the first experimentally discovered Weyl semimetal material,has attracted a lot of attention due to its high carrier mobility,high anisotropy,nonmagnetic properties and strong interaction with light.These make it an ideal candidate for the study of Weyl fermions and applications in quantum computation,thermoelectric devices,and photodetection.For further basic physics studies and potential applications,large-size and high-quality Ta As films are urgently needed.However,it is difficult to grow As-stoichiometry Ta As films due to the volatilization of As during the growth.To solve this problem,we attempted to grow Ta As films on different substrates using targets with different As stoichiometric ratios via pulsed laser deposition(PLD).In this work,we found that partial As ions of the Ga As substrate are likely to diffuse into the Ta As films during growth,which was preliminarily confirmed by structural characterization,surface topography and composition analysis.As a result,the As content in the Ta As film was improved and the Ta As phase was achieved.Our work presents an effective method for the fabrication of Ta As films using PLD,enabling possible use of the Weyl semimetal film for functional devices.展开更多
We studied the role of oxygen in Pr2 CuO_(4±δ) thin films fabricated by the polymer assisted deposition method. The magnetoresistance and Hall resistivity of Pr2 CuO_(4±δ) samples were systematically inves...We studied the role of oxygen in Pr2 CuO_(4±δ) thin films fabricated by the polymer assisted deposition method. The magnetoresistance and Hall resistivity of Pr2 CuO_(4±δ) samples were systematically investigated. It was found that with decreasing oxygen content, the low-temperature Hall coefficient(RH) and magnetoresistance changed from negative to positive, similar to those with the increase of Ce-doped concentration in R_(2-x)Ce_x CuO_4 (R = La, Nd, Pr, Sm, Eu). In addition, we observed that the dependence of the superconducting critical temperature Tc with RH for the Pr_(2-x) Ce_x CuO_4 perfectly overlapped with that of Pr_2 CuO_(4±δ) . These findings point to the fact that the doped electrons induced by the oxygen removal are responsible for the superconductivity of the T-phase parent compounds.展开更多
As an essential component of the Materials Genome Initiative aiming to shorten the period of materials research and development, combinatorial synthesis and rapid characterization technologies have been playing a more...As an essential component of the Materials Genome Initiative aiming to shorten the period of materials research and development, combinatorial synthesis and rapid characterization technologies have been playing a more and more important role in exploring new materials and comprehensively understanding materials properties. In this review, we discuss the advantages of high-throughput experimental techniques in researches on superconductors. The evolution of combinatorial thin-film technology and several high-speed screening devices are briefly introduced. We emphasize the necessity to develop new high-throughput research modes such as a combination of high-throughput techniques and conventional methods.展开更多
The high-throughput strategy has widely developed in bioinformatics and pharmaceutical industry[1].The combinatorial method is the most crucial experimental technique to put this strategy into practical application[2]...The high-throughput strategy has widely developed in bioinformatics and pharmaceutical industry[1].The combinatorial method is the most crucial experimental technique to put this strategy into practical application[2].The main idea is synthesizing samples with various physical or chemical展开更多
We report systematic in-plane magnetoresistance measurements on the electron-doped cuprate La_(2.x)Ce_xCuO_(4±δ) thin films as a function of Ce doping and oxygen content in the magnetic field up to 14 T. A cross...We report systematic in-plane magnetoresistance measurements on the electron-doped cuprate La_(2.x)Ce_xCuO_(4±δ) thin films as a function of Ce doping and oxygen content in the magnetic field up to 14 T. A crossover from negative to positive magnetoresistance occurs between the doping level x = 0.07 and 0.08. Above x = 0.08, the positive magnetoresistance effect appears, and is almost indiscernible at x = 0.15. By tuning the oxygen content, the as-grown samples show negative magnetoresistance effect, whereas the optimally annealed ones display positive magnetoresistance effect at the doping level x = 0.15. Intriguingly, a linear-field dependence of in-plane magnetoresistance is observed at the underdoping level x = 0.06, the optimal doping level x = 0.1 and slightly overdoping level x = 0.11. These anomalies of in-plane magnetoresistance may be related to the intrinsic inhomogeneity in the cuprates, which is discussed in the framework of network model.展开更多
基金Project supported by the National Key Basic Research Program of China(Grant Nos.2021YFA0718700,2018YFB0704102,2017YFA0303003,2017YFA0302902,2016YFA0300301,and 2021YFA0718802)the National Natural Science Foundation of China(Grant Nos.11927808,11834016,118115301,119611410,11961141008,61727805+5 种基金11961141002)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(CAS)(Grant Nos.QYZDB-SSW-SLH008 and QYZDY-SSW-SLH001)CAS Interdisciplinary Innovation Team,the Strategic Priority Research Program(B)of CAS(Grant Nos.XDB25000000and XDB33000000)the Beijing Natural Science Foundation(Grant No.Z190008)the Key-Area Research and Development Program of Guangdong Province,China(Grant No.2020B0101340002)the support from the China Postdoctoral Science Foundation(Grant No.2022M711497)。
文摘High quality Nb films were successfully prepared on both flexible polyimide(PI)and rigid Al2O3substrates and their transport properties were systematically studied at various applied currents,external magnetic fields,and sample orientations.It is found that a curved Nb/PI film exhibits quite different superconducting transition and vortex dynamics compared to the flat Nb/Al2O3film.For the curved Nb/PI film,smooth superconducting transitions were obtained at low currents,while unexpected cascade structures were revealed in theρ(T)curves at high currents.We attribute this phenomenon to the gradient distribution of vortex density together with a variation of superconductivity along the curved film.In addition,reentrant superconductivity was induced in the curved Nb/PI thin film by properly choosing the measurement conditions.We attribute this effect to the vortex pinning from both in-plane vortices and out-of-plane vortices.This work reveals the complex transport properties of curved superconducting thin films,providing important insights for further theoretical investigations and practical developments of flexible superconductors.
基金Project supported by the National Key Research and Development Program of China(Grant No.2021YFA0718700)the National Natural Science Foundation of China(Grant No.12174347)+1 种基金the Synergetic Extreme Condition User Facility(SECUF)the Center for Materials Genome。
文摘Ta As,the first experimentally discovered Weyl semimetal material,has attracted a lot of attention due to its high carrier mobility,high anisotropy,nonmagnetic properties and strong interaction with light.These make it an ideal candidate for the study of Weyl fermions and applications in quantum computation,thermoelectric devices,and photodetection.For further basic physics studies and potential applications,large-size and high-quality Ta As films are urgently needed.However,it is difficult to grow As-stoichiometry Ta As films due to the volatilization of As during the growth.To solve this problem,we attempted to grow Ta As films on different substrates using targets with different As stoichiometric ratios via pulsed laser deposition(PLD).In this work,we found that partial As ions of the Ga As substrate are likely to diffuse into the Ta As films during growth,which was preliminarily confirmed by structural characterization,surface topography and composition analysis.As a result,the As content in the Ta As film was improved and the Ta As phase was achieved.Our work presents an effective method for the fabrication of Ta As films using PLD,enabling possible use of the Weyl semimetal film for functional devices.
基金Project supported by the National Key Basic Research Program of China(Grant Nos.2015CB921000,2016YFA0300301,2017YFA0303003,and2018YFB0704100)the National Natural Science Foundation of China(Grant Nos.11674374 and 11474338)+2 种基金the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH008)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grants Nos.XDB07020100 and XDB07030200)the Beijing Municipal Science and Technology Project,China(Grant No.Z161100002116011)
文摘We studied the role of oxygen in Pr2 CuO_(4±δ) thin films fabricated by the polymer assisted deposition method. The magnetoresistance and Hall resistivity of Pr2 CuO_(4±δ) samples were systematically investigated. It was found that with decreasing oxygen content, the low-temperature Hall coefficient(RH) and magnetoresistance changed from negative to positive, similar to those with the increase of Ce-doped concentration in R_(2-x)Ce_x CuO_4 (R = La, Nd, Pr, Sm, Eu). In addition, we observed that the dependence of the superconducting critical temperature Tc with RH for the Pr_(2-x) Ce_x CuO_4 perfectly overlapped with that of Pr_2 CuO_(4±δ) . These findings point to the fact that the doped electrons induced by the oxygen removal are responsible for the superconductivity of the T-phase parent compounds.
基金Project supported by the National Key Basic Research Program of China(Grant Nos.2015CB921000,2016YFA0300301,2017YFA0303003,and 2017YFA0302902)the National Natural Science Foundation of China(Grant Nos.11674374,11804378,and 11574372)+3 种基金the Beijing Municipal Science and Technology Project(Grant No.Z161100002116011)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant Nos.QYZDB-SSW-SLH008 and QYZDY-SSW-SLH001)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB07020100)the Opening Project of Wuhan National High Magnetic Field Center(Grant No.PHMFF2015008)
文摘As an essential component of the Materials Genome Initiative aiming to shorten the period of materials research and development, combinatorial synthesis and rapid characterization technologies have been playing a more and more important role in exploring new materials and comprehensively understanding materials properties. In this review, we discuss the advantages of high-throughput experimental techniques in researches on superconductors. The evolution of combinatorial thin-film technology and several high-speed screening devices are briefly introduced. We emphasize the necessity to develop new high-throughput research modes such as a combination of high-throughput techniques and conventional methods.
基金This work was supported by the National Key Basic Research Program of China(2021YFA0718700,2017YFA0302900,2017YFA0303003,2018YFB0704102,and 2018YFA0305800)the National Natural Science Foundation of China(11888101,11927808,11834016,11961141008,12174428,and 12274439)+4 种基金the Strategic Priority Research Program(B)of Chinese Academy of Sciences(XDB25000000,XDB33000000)CAS Interdisciplinary Innovation Team,Beijing Natural Science Foundation(Z190008)CAS through the Youth Innovation Promotion Association(2022YSBR-048)Key-Area Research and Development Program of Guangdong Province(2020B0101340002)the Center for Materials Genome.
基金supported by the National Key Basic Research Program of China(2015CB921000,2016YFA0300301,2017YFA0302902,2017YFA0303003 and 2018YFB0704102)the National Natural Science Foundation of China(11674374 and 11834016)+3 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB25000000)the Key Research Program of Frontier Sciences,CAS(QYZDB-SSW-SLH008 and QYZDY-SSW-SLH001)CAS Interdisciplinary Innovation Teambenefited from the bilateral collaboration F.R.S.-FNRS/NSFC(V4/345-DeM-229)。
基金supported by the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH008)the National Natural Science Foundation of China(Grant Nos.11474338,and11674374)the National Key Basic Research Program of China(Grant Nos.2015CB921000,and 2016YFA0300301)
文摘The high-throughput strategy has widely developed in bioinformatics and pharmaceutical industry[1].The combinatorial method is the most crucial experimental technique to put this strategy into practical application[2].The main idea is synthesizing samples with various physical or chemical
基金supported by the National Key R&D Program of China(2021YFA0718700,2017YFA0302902,2017YFA0303003,and 2018YFB0704102)the National Natural Science Foundation of China(11834016,11961141008,11927808,and 12174428)+3 种基金the Strategic Priority Research Program(B)of Chinese Academy of Sciences(XDB25000000 and XDB33000000)the Beijing Natural Science Foundation(Z190008)CAS Interdisciplinary Innovation Team,Key-Area Research and Development Program of Guangdong Province(2020B0101340002)the Center for Materials Genome。
基金supported by the National Key Basic Research Program of China (Grant Nos. 2015CB921000, and 2016YFA0300301)the National Natural Science Foundation of China (Grant Nos. 11674374, and 11474338)the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (Grant No. QYZDB-SSW-SLH008)
文摘We report systematic in-plane magnetoresistance measurements on the electron-doped cuprate La_(2.x)Ce_xCuO_(4±δ) thin films as a function of Ce doping and oxygen content in the magnetic field up to 14 T. A crossover from negative to positive magnetoresistance occurs between the doping level x = 0.07 and 0.08. Above x = 0.08, the positive magnetoresistance effect appears, and is almost indiscernible at x = 0.15. By tuning the oxygen content, the as-grown samples show negative magnetoresistance effect, whereas the optimally annealed ones display positive magnetoresistance effect at the doping level x = 0.15. Intriguingly, a linear-field dependence of in-plane magnetoresistance is observed at the underdoping level x = 0.06, the optimal doping level x = 0.1 and slightly overdoping level x = 0.11. These anomalies of in-plane magnetoresistance may be related to the intrinsic inhomogeneity in the cuprates, which is discussed in the framework of network model.
