Exchange Interactions in Bcc Co: Implications for Temperature Dependence of TMR

Author

Oset, Shawn J. ; Butler, W.H.

Author_Institution

Dept. of Phys., Univ. of South Alabama, Mobile, AL

Volume

43

Issue

6

fYear

2007

fDate

6/1/2007 12:00:00 AM

Firstpage

2794

Lastpage

2796

Abstract

Yuasa recently constructed Co/MgO/Co magnetic tunneling junctions (MTJs) with bcc Co(100) electrodes. These MTJs exhibited a magnetoresistance ratio of 410% at room temperature, and 507% at 20 K. The weak temperature dependence in comparison to Fe based electrodes led them to speculate that the weak temperature dependence may be due to exceptionally strong exchange interactions in bcc Co. Here we report on a theoretical investigation of the nearest neighbour exchange interactions in bcc Co

Keywords

antiferromagnetic materials; cobalt; exchange interactions (electron); ferrimagnetic materials; ferromagnetic materials; magnesium compounds; magnetic moments; tunnelling magnetoresistance; Co-MgO; Co-MgO(100) MTJ; TMR; antiferromagnetic state; bcc cobalt electrodes; ferrimagnetic state; magnetic moments; nearest neighbour exchange interactions; tunneling magnetoresistance; Atomic measurements; Electrodes; Electrons; Elementary particle exchange interactions; Iron; Magnetic moments; Magnetic tunneling; Nearest neighbor searches; Temperature dependence; Tunneling magnetoresistance; Curie temperature; bcc Co; exchange interaction;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2007.894141

Filename

4202662