Effects of interface oxidization in ferromagnetic tunnel junctions

Author

Sato, Masashige ; Kikuchi, Hideyuki ; Kobayashi, Kazuo

Author_Institution

Fujitsu Labs. Ltd., Atsugi, Japan

Volume

35

Issue

5

fYear

1999

fDate

9/1/1999 12:00:00 AM

Firstpage

2946

Lastpage

2948

Abstract

We fabricated Ni-Fe/Co/Al-AlO/Co/Ni-Fe/Fe-Mn/Ni-Fe ferromagnetic tunnel junctions in which the bottom Co surface is exposed or not to air. While the MR ratio increased by annealing for the sample in which bottom Co surface was exposed to air, it decreased for the sample in which bottom Co surface was not exposed to air. This suggests that a slightly oxidized layer at the bottom Co/Al interface acts as a diffusion prevention layer. Moreover, the voltage-resistance dependence became asymmetric following annealing of the sample with a non oxidized Co surface and the bias dependence of MR ratio was improved

Keywords

alumina; aluminium; annealing; cobalt; diffusion barriers; ferromagnetic materials; giant magnetoresistance; interface structure; iron alloys; magnetic multilayers; manganese alloys; nickel alloys; oxidation; tunnelling; MR ratio; NiFe-Co-Al-Al₂O₃-Co-NiFe-NiMn-NiFe; NiFe/Co/Al-AlO/Co/NiFe/FeMn/NiFe ferromagnetic tunnel junctions; annealing; bias dependence; bottom Co surface; bottom Co/Al interface; diffusion prevention layer; ferromagnetic tunnel junctions; interface oxidization; slightly oxidized layer; voltage-resistance dependence; Annealing; Laboratories; Lithography; Magnetic field measurement; Magnetic films; Magnetic separation; Sputtering; Surface fitting; Temperature; Voltage;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.801039

Filename

801039