Coexistence of large positive and negative magnetoresistance in Cr_(2)Si_(2)Te_(6) ferromagnetic semiconductor  

Cr_(2)Si_(2)Te_(6)铁磁半导体中大的正、负磁阻共存现象

作　　者：Zhou Li Wei Bai Yuliang Li Yuanlong Li Sheng Wang Weihui Zhang Jiyin Zhao Zhe Sun Chong Xiao Yi Xie 李周;白巍;李昱良;李渊龙;王盛;张炜辉;赵继印;孙喆;肖翀;谢毅(Hefei National Laboratory for Physical Sciences at the Microscale,CAS Center for Excellence in Nanoscience,University of Science and Technology of China,Hefei 230026,China;Institute of Energy,Hefei Comprehensive National Science Center,Hefei 230031,China;National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,China)

机构地区：[1]Hefei National Laboratory for Physical Sciences at the Microscale,CAS Center for Excellence in Nanoscience,University of Science and Technology of China,Hefei 230026,China [2]Institute of Energy,Hefei Comprehensive National Science Center,Hefei 230031,China [3]National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,China

出　　处：《Science China Materials》2022年第3期780-787,共8页中国科学（材料科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(U1832142 and 21805269);the National Key R&D Program of China(2018YFB0703602 and 2017YFA0303500);the Youth Innovation Promotion Association,CAS(Y202092);the Fundamental Research Funds for the Central Universities(WK2340000094);The University Synergy Innovation Program of Anhui Province(GXXT-2020-003);Anhui Provincial Natural Science Foundation(1808085QA08);the Key Research Program of Frontier Sciences(QYZDYSSW-SLH011);China Postdoctoral Science Foundation(2017M620261,2019TQ0293 and 2020M671868);the National Synchrotron Radiation Laboratory Joint funds of University of Science and Technology of China(KY2060000156 and KY2340000114)。

摘　　要：Magnetoresistance(MR)phenomenon couples the electron transport with magnetic field,which has been at the forefront of condensed matter physics and materials science.Large-MR behaviors are of particularly importance for magnetic sensor and information memory applications,and their scarcity has aroused intensive research.Moreover,due to the different physical origins,combination of large positive and negative MR(pMR and nMR)in one single compound has rarely been reported.In present work,we achieved a coexistence of large pMR and nMR in Cr_(2)Si_(2)Te_(6) ferromagnetic semiconductor single crystal with different field configurations.Specifically,a large nMR of about -60% was obtained under the in-plane field,while a large pMR higher than 1000% took over in the out-of-plane direction.We attribute this field direction-sensitive dualistic large MR behavior to the competition and cooperation effect from the ferromagnetic interaction,orbital scattering and electronic correlation that coexist in Cr_(2)Si_(2)Te_(6),which contribute to n MR,pMR,and nMR,respectively,in dominated temperature and field ranges,and show different weights under different field directions.The elucidated multiple MR mechanism in this ferromagnetic semiconductor will shed light on the pursuit of coexistence of large p MR and nMR for field-sensitive device applications.磁阻(MR)作为一种电子输运与磁场耦合的宏观现象,一直是凝聚态物理和材料科学的研究前沿.其中,大的磁阻现象及材料对磁传感器和信息存储应用尤为重要,而这种材料的稀缺也引起了人们的广泛关注.此外,由于物理起源不同,在一种化合物中同时存在大的正、负磁阻少见报道.本工作中,我们在Cr_(2)Si_(2)Te_(6)铁磁半导体单晶中实现了不同磁场方向下大的正磁阻(pMR)和负磁阻(nMR)共存.具体而言,在面内场方向获得了约-60%的大的nMR,在面外场方向获得了高于1000%的大的pMR.我们将这种磁场方向依赖的磁阻行为归因于Cr_(2)Si_(2)Te_(6)中的铁磁相互作用、轨道散射和电子关联作用的竞争和合作效应,它们在相应温度和磁场范围内分别使Cr_(2)Si_(2)Te_(6)表现出nMR,pMR和nMR.阐明这种铁磁半导体中的磁阻机制将为寻求大的pMR和nMR共存的磁场敏感器件提供指导.

关 键 词：large pMR and nMR dualistic magnetoresistance Cr_(2)Si_(2)Te_(6) ferromagnetic semiconductor single crystal 

分 类 号：O469[理学—凝聚态物理]