Temperature dependence of tunneling magnetoresistance in epitaxial magnetic tunnel junctions using a Co2FeAl Heusler alloy electrode

被引：77

作者：

Wang, Wenhong ^{[1
,2
]}

Sukegawa, Hiroaki ^{[1
]}

Inomata, Koichiro ^{[1
]}

机构：

[1] Natl Inst Mat Sci, Magnet Mat Ctr, Tsukuba, Ibaraki 3050047, Japan

[2] Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter Phys, Beijing 100080, Peoples R China

来源：

PHYSICAL REVIEW B | 2010年 / 82卷 / 09期

关键词：

ROOM-TEMPERATURE;

D O I：

10.1103/PhysRevB.82.092402

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Spin-valve-type epitaxial magnetic tunnel junctions (MTJs) consisting of a full-Heusler alloy Co2FeAl (CFA) and a MgO tunnel barrier were fabricated on a single-crystal MgO(001) substrate using sputtering method for all the layers. Experimental temperature-dependent tunnel magnetoresistance in the MTJs was revealed to be fitted well using spin wave excitation model for tunneling spin polarization, P(T) = P-0(1-alpha T-3/2) up to room temperature, where P-0 is the spin polarization at 0 K and alpha is a fitting parameter. The determined P and alpha are shown to be significantly different between bottom and top CFA electrodes facing a MgO barrier. It is demonstrated that the bottom CFA deposited on a Cr buffer has a low alpha and behaves as a half-metal with P similar to 1 in terms of the Delta(1) symmetry due to the coherent tunneling through a MgO barrier.

引用

页数：4

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