Intergranular magnetoresistance in Sr2FeMoO6 from a magnetic tunnel barrier mechanism across grain boundaries

被引：126

作者：

Sarma, D. D. ^{[1
]}

Ray, Sugata

Tanaka, K.

Kobayashi, M.

Fujimori, A.

Sanyal, P.

Krishnamurthy, H. R.

Dasgupta, C.

机构：

[1] Indian Inst Sci, Solid State & Struct Chem Unit, Bangalore 560012, Karnataka, India

[2] Indian Inst Sci, Dept Phys, Ctr Condensed Matter Theory, Bangalore 560012, Karnataka, India

[3] Indian Assoc Cultivat Sci, Ctr Adv Mat, Kolkata 700032, W Bengal, India

[4] Tokyo Inst Technol, Mat & Stuct Lab, Yokohama, Kanagawa 2268503, Japan

[5] Univ Tokyo, Dept Phys, Tokyo 1130033, Japan

[6] Univ Tokyo, Dept Complex Sci & Engn, Bunkyo Ku, Tokyo 1130033, Japan

[7] Jawaharlal Nehru Ctr Adv Sci Res, Bangalore, Karnataka, India

来源：

PHYSICAL REVIEW LETTERS | 2007年 / 98卷 / 15期

关键词：

D O I：

10.1103/PhysRevLett.98.157205

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We present magnetization (M) and magnetoresistance (MR) data for a series of Sr2FeMoO6 samples with independent control on antisite defect and grain-boundary densities, which reveal several unexpected features, including a novel switching-like behavior of MR with M. These, in conjunction with model calculations, establish that the MR in Sr2FeMoO6 is dominantly controlled by a new mechanism, derived from the magnetic polarization of grain-boundary regions acting like spin valves, leading to behavior qualitatively different from that usually encountered in tunneling MR. We show that a simple and useful experimental signature for the presence of this spin-valve-type MR (SVMR) is a wider hysteresis in MR compared to that in M.

引用

页数：4