Frequency regulation in alternation-current transports across metal to insulator transitions of thin film correlated perovskite nickelates  

作　　者：Haifan Li Fanqi Meng Yi Bian Xuanchi Zhou Jiaou Wang Xiaoguang Xu Yong Jiang Nuofu Chen Jikun Chen 

机构地区：[1]School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China [2]School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China [3]Beijing Synchrotron Radiation Facility,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China [4]School of Renewable Energy,North China Electric Power University,Beijing 102206,China

出　　处：《Journal of Materials Science & Technology》2023年第17期235-241,共7页材料科学技术（英文版）

基　　金：financially supported by the National Key Re-search and Development Program of China(No.2021YFA0718900);the National Natural Science Foundation of China(Nos.62074014 and 52073090);the Beijing New-star Plan of Science and Tech-nology(No.Z191100001119071).

摘　　要：Although the metal to insulator transition(MIT)observed in d-band correlated metal oxides enables promising applications(e.g.,correlated logical devices and Mottronic devices),its present recognition is mainly limited on the direct current(DC)electrical transports.Up to date,the MIT from the perspective of alternation current(AC)transport and its potential electronic applications remains yet unclear.Herein,we demonstrate the frequency(f_(AC))dependence in the impedance(Z=Z’+iZ″)of typical MIT materials,such as thin film rare-earth nickelates(Re NiO_(3)),across the critical MIT temperature(T_(MIT)).Apart from the abrupt change in the impedance modulus(|Z|)across the critical temperature(T_(MIT))similar to the DC transport,the MIT also triggers non-continuous variation in the impedance phase(θ),and this enables the f_(AC)-regulations in the Z’-T tendencies(Z’=|Z|cosθ).At the critical f_(AC) range(e.g.,104-106 Hz),the con-versing variations in|Z|-T and cosθ-T across T_(MIT) result in non-monotonic delta-shape Z’-T tendency in Sm_(x) Nd_(1-x) NiO_(3),the full width half maximum of which is effectively narrowed compared to the situation with the absence of MIT.Further imparting lower or higher f_(AC) elevate the domination in|Z|-T and cosθ-T,respectively,but also enables abrupt Z’-T tendencies across T_(MIT) showing negative temperature coefficient of resistance(NTCR)or positive temperature coefficient of resistance(PTCR).By introducing f_(AC) as a new freedom,the MIT behavior can be more comprehensively regulated electronically,and this extends the vision in exploring the new electronic applications based on the correlated MIT materials from the AC perspective.

关 键 词：Metal to insulator transition Rare earth nickelates Electrical transportations Impedance Perovskite oxide Electronic correlation 

分 类 号：TB34[一般工业技术—材料科学与工程]