X-ray absorption and X-ray magnetic circular dichroism studies of a monatomic bcc-Co(001) layer facing an amorphous Al-O tunnel barrier

Author

Katayama, T. ; Saito, T. ; Saito, S. ; Kurosaki, Y. ; Miyokawa, K. ; Kamino, T. ; Kobayashi, K. ; Suzuki, Y. ; Yuasa, S. ; Manaka, H. ; Koide, T.

Author_Institution

Nat. Inst. of Adv. Ind. Sci. & Technol., Japan

fYear

2005

fDate

4-8 April 2005

Firstpage

1987

Lastpage

1988

Abstract

Tunnel magnetoresistance (TMR) effect attracts much attention. Magnetic tunnel junctions (MTJs) with an amorphous Al-O tunnel barrier show large magnetoresistance ratio up to 70%. The orbital and spin moments of the 1 ML-Co(001) facing Al-O barrier, Al and Au metal layers were evaluated using X-ray magnetic circular dichroism (XMCD). X-ray absorption spectroscopy (XAS) was used to evaluate the oxidization state of the 1 ML-Co [001]. XAS and XMCD of the samples were measured from 635 to 855 eV. XAS data of the samples showed absence of oxidization in ML-Co layer. This indicates that the oxidization process of top Al layer was terminated without oxidizing the Co layer. The magnetic moments of 1 ML-Co was found larger than that of bulk Co indicating also that the Co layer adjacent to Al-O barrier is not oxidized.

Keywords

X-ray absorption spectra; aluminium; amorphous state; copper; gold; magnetic circular dichroism; magnetic moments; magnetic multilayers; oxidation; tunnelling magnetoresistance; 635 to 855 eV; AlO-Au-Al-Co-Fe; Au; TMR; X-ray absorption; X-ray magnetic circular dichroism; XAS; XMCD; amorphous Al-O tunnel barrier; magnetic moments; magnetic tunnel junctions; monatomic bcc-Co(001) layer; orbital moments; oxidization state; spin moments; tunnel magnetoresistance;

fLanguage

English

Publisher

ieee

Conference_Titel

Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International

Print_ISBN

0-7803-9009-1

Type

conf

DOI

10.1109/INTMAG.2005.1464432

Filename

1464432