Effect of polarizer dynamics on current-induced behaviors in magnetic nanopillars

被引：8

作者：

Urazhdin, Sergei ^{[1
]}

Lim, Weng Lee ^{[1
]}

Higgins, Andrew ^{[1
]}

机构：

[1] W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA

来源：

PHYSICAL REVIEW B | 2009年 / 80卷 / 14期

基金：

美国国家科学基金会;

关键词：

PHASE-LOCKING; DRIVEN; MAGNETORESISTANCE;

D O I：

10.1103/PhysRevB.80.144411

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Magnetoelectronic nanodevices such as magnetic random access memory include two essential magnetic layers: a polarizing reference layer and a free layer whose configuration can be changed by spin-polarized current via spin-transfer effect. We present measurements of current-induced behaviors in nanodevices with fixed dimensions of the free layer, and varied dimensions of the polarizer. Current-induced precession occurs only at positive current for sufficiently thick polarizer, and only at negative current for thin polarizer, with an abrupt transition between these regimes. Bipolar current-induced precession was observed for a small range of extended polarizer thickness but the amplitude of precession in these devices is reduced. These behaviors are interpreted in terms of the coupling between magnetic layers caused by spin transfer. We suggest a device architecture utilizing the coupling for improved efficiency.

引用

页数：10

共 22 条

[1] Controlled normal and inverse current-induced magnetization switching and magnetoresistance in magnetic nanopillars [J].

AlHajDarwish, M ;

Kurt, H ;

Urazhdin, S ;

Fert, A ;

Loloee, R ;

Pratt, WP ;

Bass, J .

PHYSICAL REVIEW LETTERS, 2004, 93 (15) :157203-1

[2] Spin-torque driven magnetization dynamics: Micromagnetic modeling [J].

Berkov, D. V. ;

Miltat, J. .

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 2008, 320 (07) :1238-1259

[3] Spin-torque ferromagnetic resonance measurements of damping in nanomagnets [J].

Fuchs, G. D. ;

Sankey, J. C. ;

Pribiag, V. S. ;

Qian, L. ;

Braganca, P. M. ;

Garcia, A. G. F. ;

Ryan, E. M. ;

Li, Zhi-Pan ;

Ozatay, O. ;

Ralph, D. C. ;

Buhrman, R. A. .

APPLIED PHYSICS LETTERS, 2007, 91 (06)

[4] Adjustable spin torque in magnetic tunnel junctions with two fixed layers [J].

Fuchs, GD ;

Krivorotov, IN ;

Braganca, PM ;

Emley, NC ;

Garcia, AGF ;

Ralph, DC ;

Buhrman, RA .

APPLIED PHYSICS LETTERS, 2005, 86 (15) :1-3

[5] Angular dependence of the microwave-generation threshold in a nanoscale spin-torque oscillator [J].

Gerhart, G. ;

Bankowski, E. ;

Melkov, G. A. ;

Tiberkevich, V. S. ;

Slavin, A. N. .

PHYSICAL REVIEW B, 2007, 76 (02)

[6]

HANDLEY RC, 2000, MODERN MAGNETIC MAT, P61601

[7] Mutual phase-locking of microwave spin torque nano-oscillators [J].

Kaka, S ;

Pufall, MR ;

Rippard, WH ;

Silva, TJ ;

Russek, SE ;

Katine, JA .

NATURE, 2005, 437 (7057) :389-392

[8] Microwave oscillations of a nanomagnet driven by a spin-polarized current [J].

Kiselev, SI ;

Sankey, JC ;

Krivorotov, IN ;

Emley, NC ;

Schoelkopf, RJ ;

Buhrman, RA ;

Ralph, DC .

NATURE, 2003, 425 (6956) :380-383

[9] Measurements of out-of-plane dynamics induced in magnetic nanopillars by spin transfer [J].

Lim, Weng Lee ;

Higgins, Andrew ;

Urazhdin, Sergei .

PHYSICAL REVIEW B, 2009, 80 (10)

[10] NOISE IN SEMICONDUCTORS - SPECTRUM OF A 2-PARAMETER RANDOM SIGNAL [J].

MACHLUP, S .

JOURNAL OF APPLIED PHYSICS, 1954, 25 (03) :341-343

← 1 2 3 →