Spin-dependent tunneling in double tunnel junctions with a discontinuous intermediate layer

Author

Saito, Y. ; Nakajima, K. ; Tanaka, K. ; Inomata, K.

Author_Institution

R&D Center, Toshiba Corp., Kawasaki, Japan

Volume

35

Issue

5

fYear

1999

fDate

9/1/1999 12:00:00 AM

Firstpage

2904

Lastpage

2906

Abstract

Detailed characteristics and tunnel magnetoresistance (TMR) properties of the double tunnel junctions (DTJs) through Co₈₀Pt₂₀ hard magnetic particles were investigated in the low barrier height regime. Significant difference in current distribution effect was observed in DTJs through discontinuous particles. No geometrically enhanced magnetoresistance occurs in the cross-shaped 0.01 mm² size junctions when the measured junction resistance is 10 times smaller than the electrode resistance due to the decrease in the effective junction area in DTJs with discontinuous ferromagnetic particles. Moreover, temperature independent TMR ratio and enhancement of the TMR ratio in a low bias voltage regime were observed in DTJs through Co₈₀Pt₂₀ hard magnetic particles in low barrier height regime

Keywords

cobalt alloys; ferromagnetic materials; magnetic multilayers; magnetic particles; magnetoresistance; permanent magnets; platinum alloys; tunnelling; Co₈₀Pt₂₀; Co₈₀Pt₂₀ hard magnetic particles; current distribution effect; discontinuous ferromagnetic particles; discontinuous intermediate layer; discontinuous particles; double tunnel junctions; effective junction area; electrode resistance; junction resistance; low barrier height regime; low bias voltage regime; spin-dependent tunneling; tunnel magnetoresistance; Area measurement; Current distribution; Electrical resistance measurement; Enhanced magnetoresistance; Magnetic particles; Magnetic properties; Magnetic tunneling; Particle measurements; Size measurement; Tunneling magnetoresistance;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.801020

Filename

801020