Tunneling magnetotransport in nanogranular-in-gap structure

Author

Jalil, M.B.A.

Author_Institution

Electr. & Comput. Eng. Dept., Nat. Univ. of Singapore, Singapore

Volume

38

Issue

5

fYear

2002

fDate

9/1/2002 12:00:00 AM

Firstpage

2613

Lastpage

2615

Abstract

Monte Carlo modeling was performed to investigate the combined effect of Coulomb blockade and spin-dependent tunneling on charge transport in a granular-in-gap structure, consisting of superparamagnetic Co grains embedded in an insulating matrix between contact electrodes. The tunneling magnetoresistance (TMR) response shows distinct temperature and field dependence, for different types of contacts - nonmagnetic, soft or hard ferromagnetic. These results contrast sharply with predictions by Inoue and Maekawa (1996) based on an infinite granular array, and can be explained by the role of the contacts in the initial rate-determining step.

Keywords

Coulomb blockade; MIM structures; Monte Carlo methods; cobalt; discontinuous metallic thin films; ferromagnetic materials; interface magnetism; magnetisation; magnetoresistance; nanostructured materials; superparamagnetism; tunnelling; Co; Coulomb blockade; Langevin function; Monte Carlo modeling; charge transport; contact electrodes; field dependence; free energy; insulating matrix; intergranular magnetization; nanogranular-in-gap structure; single-charge tunneling; spin-dependent tunneling; superparamagnetic grains; temperature dependence; tunneling magnetoresistance response; tunneling magnetotransport; Electrodes; Insulation; Magnetic films; Magnetic heads; Magnetic tunneling; Material storage; Monte Carlo methods; Nanostructures; Temperature dependence; Tunneling magnetoresistance;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2002.803202

Filename

1042288