Defect-manipulated magnetoresistance and above-room-temperature ferromagnetism in two-dimensional BaNi_(2)V_(2)O_(8)  

作　　者：Pengfei Tan Chuanhui Zhu Jinjin Yang Shuang Zhao Tao Xia Mei-Huan Zhao Tao Han Zheng Deng Man-Rong Li 

机构地区：[1]Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education,School of Chemistry,Sun Yat-sen University,Guangzhou 510006,China [2]School of Science and Engineering,The Chinese University of Hong Kong,Shenzhen 518172,China [3]Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [4]School of Science,Hainan University,Haikou 570228,China

出　　处：《Chinese Chemical Letters》2024年第3期523-527,共5页中国化学快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(NSFC,Nos.21875287,22090041);the Guangdong Basic and Applied Basic Research Foundation(No.2022B1515120014)。

摘　　要：The intricate correlation between multiple degrees of freedom and physical properties is a fascinating area in solid state chemistry and condensed matter physics.Here,we report a quantum-magnetic system BaNi_(2)V_(2)O_(8)(BNVO),in which the spin correlation was modulated by unusual oxidation state,leading to different magnetic behavior.The BNVO was modified with topochemical reduction(TR)to yield TR-BNVO with partially reduced valance state of Ni^(+)in the two-dimensional NiO_(6)-honeycomb lattice.Accordingly,the antiferromagnetic order is suppressed by the introduction of locally interposed Ni^(+)and oxygen vacancies,resulting in a ferromagnetic ground state with the transition temperature up to 710 K.A positive magnetoresistance(7.5%)was observed in the TR-BNVO at 40 K under 7 T.These findings show that topological reduction is a powerful approach to engineer low-dimensional materials and accelerate the discovery of new quantum magnetism.

关 键 词：Layered honeycomb oxide Topochemical reduction Oxygen vacancies FERROMAGNETISM MAGNETORESISTANCE 

分 类 号：TB34[一般工业技术—材料科学与工程]