Observation of Intermediate States in Magnetic Tunnel Junctions With Composite Free Layer

Author

Yao, Xiaofeng ; Malmhall, Roger ; Ranjan, Rajiv ; Wang, Jian-Ping

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Minnesota, Minneapolis, MN

Volume

44

Issue

11

fYear

2008

Firstpage

2496

Lastpage

2499

Abstract

The current-induced magnetization switching was studied in the MTJ devices with composite free layer (CoFeB/CoFeB-oxide/CoFeB). The stable intermediate state was observed due to the multi-domain structure induced by the dipole field and large device size. Two different stable intermediate states were observed in different applied current direction. The switching mechanisms of those two intermediate states are different, which is also indicated by the switching current distribution. Reversible intermediate state was also observed at low applied current, which may be due to the domain nucleation.

Keywords

boron alloys; cobalt alloys; iron alloys; magnetic domains; magnetic multilayers; magnetic switching; magnetic tunnelling; nucleation; silicon compounds; CoFeB-CoFeB-SiO₂-CoFeB; MTJ devices; current-induced magnetization switching; dipole field; domain nucleation; magnetic tunnel junctions; multidomain structure; Composite free layer; current-induced magnetization switching; intermediate state; magnetic random-access memory (MRAM); magnetic tunnel junction; spin transfer;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2008.2003072

Filename

4717497