Current-dependent positive magnetoresistance in La_(0.8)Ba_(0.2)MnO_(3)ultrathin films

作     者：Guankai Lin Haoru Wang Xuhui Cai Wei Tong Hong Zhu 林冠凯;王昊儒;蔡旭晖;童伟;朱弘

作者机构：Department of PhysicsUniversity of Science and Technology of ChinaHefei 230026China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme ConditionsHigh Magnetic Field Laboratory of the Chinese Academy of SciencesHefei 230031China Key Laboratory of Strongly-Coupled Quantum Matter PhysicsChinese Academy of SciencesHefei 230026China 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2021年第30卷第9期

页      面：513-519页

核心收录：

学科分类：08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.11674298) the National Key Research and Development Program of China(Grant No.2017YFA0403502) the Users with Excellence Project of Hefei Science Center CAS(Grant No.2018HSC-UE013) 

主　　题：positive magnetoresistance electroresistance Joule self-heating conductive filament 

摘      要：We report an investigation into the magnetoresistance(MR)of La_(0.8)Ba_(0.2)MnO_(3)ultrathin films with various *** the 13 nm-thick film shows the commonly reported negative magnetoresistive effect,the 6 nm-and 4 nm-thick films display unconventional positive magnetoresistive(PMR)behavior under certain *** well as the dependence on the film s thickness,it has been found that the electrical resistivity and the PMR effect of the thinner films are very dependent on the test *** example,the magnetoresistive ratio of the 4 nm-thick film changes from+46%to-37%when the current is increased from 10 nA to 100 nA under 15 kOe at 40 *** addition,the two thinner films present opposite changes in electrical resistivity with respect to the test current,i.e.,the electroresistive(ER)effect,at low *** discuss the complex magnetoresistive and ER behaviors by taking account of the weak contacts at grain boundaries between ferromagnetic metallic(FMM)*** PMR effect can be attributed to the breaking of the weak contacts due to the giant magnetostriction of the FMM grains under a magnetic *** the competing effects of the conductive filament and local Joule self-heating at grain boundaries on the transport properties,the dissimilar ER effects in the two thinner films are also *** experimental findings provide an additional approach for tuning the magnetoresistive effect in manganite films.