Current-dependent positive magnetoresistance in La0.8Ba0.2MnO3 ultrathin films*

doi:10.1088/1674-1056/ac012d

	Current-dependent positive magnetoresistance in La0.8Ba0.2MnO3 ultrathin films*
	Lin, Guankai 1; Wang, Haoru 1; Cai, Xuhui 1; Tong, Wei 2; Zhu, Hong 1,3
刊名	CHINESE PHYSICS B
	2021-09-01
卷号	30
关键词	positive magnetoresistance electroresistance Joule self-heating conductive filament
ISSN号	1674-1056
DOI	10.1088/1674-1056/ac012d
通讯作者	Zhu, Hong(zhuh@ustc.edu.cn)
英文摘要	We report an investigation into the magnetoresistance (MR) of La0.8Ba0.2MnO3 ultrathin films with various thicknesses. While 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 conditions. As 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 current. For 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 K. In 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 temperatures. We discuss the complex magnetoresistive and ER behaviors by taking account of the weak contacts at grain boundaries between ferromagnetic metallic (FMM) grains. The PMR effect can be attributed to the breaking of the weak contacts due to the giant magnetostriction of the FMM grains under a magnetic field. Considering 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 understandable. These experimental findings provide an additional approach for tuning the magnetoresistive effect in manganite films.
资助项目	National Natural Science Foundation of China[11674298] ; National Key Research and Development Program of China[2017YFA0403502] ; Users with Excellence Project of Hefei Science Center CAS[2018HSC-UE013]
WOS关键词	ELECTRICAL-TRANSPORT ; ELECTRORESISTANCE ; MAGNETOSTRICTION ; MAGNETOTRANSPORT ; BEHAVIOR
WOS研究方向	Physics
语种	英语
出版者	IOP PUBLISHING LTD
WOS记录号	WOS:000692241200001
资助机构	National Natural Science Foundation of China ; National Key Research and Development Program of China ; Users with Excellence Project of Hefei Science Center CAS
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/125261]
专题	中国科学院合肥物质科学研究院
通讯作者	Zhu, Hong
作者单位	1.Univ Sci & Technol China, Dept Phys, Hefei 230026, Peoples R China 2.Chinese Acad Sci, High Magnet Field Lab, Anlitu Prov Key Lab Condensed Matter Phys Extreme, Hefei 230031, Peoples R China 3.Chinese Acad Sci, Key Lab Strongly Coupled Quantum Matter Phys, Hefei 230026, Peoples R China
推荐引用方式 GB/T 7714	Lin, Guankai,Wang, Haoru,Cai, Xuhui,et al. Current-dependent positive magnetoresistance in La0.8Ba0.2MnO3 ultrathin films*[J]. CHINESE PHYSICS B,2021,30.
APA	Lin, Guankai,Wang, Haoru,Cai, Xuhui,Tong, Wei,&Zhu, Hong.(2021).Current-dependent positive magnetoresistance in La0.8Ba0.2MnO3 ultrathin films*.CHINESE PHYSICS B,30.
MLA	Lin, Guankai,et al."Current-dependent positive magnetoresistance in La0.8Ba0.2MnO3 ultrathin films*".CHINESE PHYSICS B 30(2021).