Giant magnetoresistance in a low-temperature GaAs/MnAs nanoscale ferromagnet hybrid structure

被引：54

作者：

Wellmann, PJ ^{[1
]}

Garcia, JM ^{[1
]}

Feng, JL ^{[1
]}

Petroff, PM ^{[1
]}

机构：

[1] Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA

来源：

APPLIED PHYSICS LETTERS | 1998年 / 73卷 / 22期

关键词：

D O I：

10.1063/1.122748

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We report the observation of a giant magnetoresistance effect in a low-temperature (LT)-GaAs/MnAs nanoscale ferromagnet hybrid structure. The MnAs nanomagnets are formed by ion implantation of Mn into LT GaAs and subsequent annealing. We have studied the magnetotransport using a vertically biased p(+)-GaAs/LT-GaAs:MnAs/p(+)-GaAs structure. A negative magneto-resistance (Delta rho/rho = [rho(B) - rho(0)]/rho(0)) of up to -80% (B = 7 T) is observed at low temperatures (T < 20 K), which changes its sign from negative to positive between T = 15 K and T = 20 K. The value of the positive magnetoresistance decreases with increasing temperature from +115% (20 K) to +1.4% (300 K). The magnetoresistance variations with B and T are correlated with the nanomagnet spacing in the structure. (C) 1998 American Institute of Physics. [S0003-6951(98)03148-9].

引用

页码：3291 / 3293

页数：3

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