Sign of tunneling magnetoresistance in CrO2-based magnetic tunnel junctions

被引：24

作者：

Leo, Titus ^{[1
]}

Kaiser, Christian ^{[2
]}

Yang, Hyunsoo ^{[2
]}

Parkin, Stuart S. P. ^{[2
]}

Sperlich, Martin ^{[3
]}

Guetherodt, Gernot ^{[3
]}

Smith, David J. ^{[4
]}

机构：

[1] Arizona State Univ, Sch Mat, Tempe, AZ 85287 USA

[2] IBM Almaden Res Ctr, San Jose, CA 95120 USA

[3] Univ Aachen, Rhein Westfal TH Aachen, Inst Phys, D-52056 Aachen, Germany

[4] Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA

来源：

APPLIED PHYSICS LETTERS | 2007年 / 91卷 / 25期

关键词：

D O I：

10.1063/1.2825475

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Half-metallic ferromagnets are potentially useful as electrodes in magnetic tunnel junctions (MTJs) because of the possibility for 100% spin polarization near the Fermi energy. We report tunneling magnetoresistance (TMR) behavior of MTJs having epitaxial CrO2(100) as one electrode, CoFe as second electrode, and MgO as tunnel barrier, i.e., TiO2(100)/CrO2(100)/MgO/CoFe. When CrO2 is exposed to air, several monolayers of oxide surface decompose and negative MR is observed. Conversely, sample surfaces protected by thin Mg layers show small but positive MR consistent with intrinsic spin polarization. Thus, the TMR sign can be reversed simply by subtle modifications to the CrO2/MgO interface.

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页数：3

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