High exchange-coupling field and thermal stability of antiferromagnetic Ir-Mn pinned spin-valve films

Author

Hwang, J.Y. ; Kim, M.Y. ; Rhee, J.R. ; Lee, S.S. ; Hwang, D.G. ; Lee, S.H. ; Yu, S.C.

Author_Institution

Sookmyung Women´´s Univ., Seoul, South Korea

Volume

38

Issue

5

fYear

2002

fDate

9/1/2002 12:00:00 AM

Firstpage

2764

Lastpage

2766

Abstract

IrMn pinned spin-valve (SV) films with stacks of Ta-NiFe-IrMn-CoFe-Cu-CoFe-NiFe-Ta were prepared by dc sputtering onto thermally oxidized Si[111] substrates at room temperature under a magnetic field of about 100 Oe. The annealing cycle number and temperature dependence of the exchange-coupling field (H_ex), magnetoresistance (MR) ratio, and coercivity (H_c) were investigated. By optimizing the process of deposition and the post-thermal annealing condition, we obtained the IrMn-based SV films with MR ratio of 3.6%, H_ex of 1180 Oe for the pinned layer. The H_ex is stabilized after the second annealing cycle, and it is thought that this SV reveals high thermal stability. The H_ex maintained its strength of 600 Oe in operation up to 240°C and decreased monotonically to zero at 270°C.

Keywords

antiferromagnetic materials; coercive force; exchange interactions (electron); iridium alloys; magnetic annealing; magnetic thin films; manganese alloys; spin valves; sputtered coatings; thermal stability; 240 to 270 degC; DC sputtering; Si; Si[111] substrate; Ta-NiFe-IrMn-CoFe-Cu-CoFe-NiFe-Ta; annealing cycle number; antiferromagnetic Ir-Mn pinned spin valve film; coercivity; exchange coupling field; magnetic field; magnetoresistance ratio; temperature dependence; thermal stability; Annealing; Antiferromagnetic materials; Giant magnetoresistance; Iron; Magnetic field measurement; Magnetic films; Sputtering; Temperature; Thermal stability; X-ray diffraction;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2002.803161

Filename

1042348