Spin Transfer Switching and MR Properties of Co/Pt Multilayered Free Layers for Submicron Sized Magneto-Optical Light Modulation Device

Author

Machida, Kenji ; Furukawa, Keiji ; Funabashi, Nobuhiko ; Aoshima, Ken-ichi ; Kuga, Kiyoshi ; Ishibashi, Takayuki ; Shimidzu, Naoki

Author_Institution

Sci. & Technol. Res. Labs., Japan Broadcasting Corp. (NHK), Tokyo, Japan

Volume

46

Issue

6

fYear

2010

fDate

6/1/2010 12:00:00 AM

Firstpage

2171

Lastpage

2174

Abstract

Co/Pt multilayered films show strong perpendicular magnetic anisotropy and have a large magneto-optical Kerr effect in the short wavelength side. To use these films with submicron spatial light modulators driven by spin transfer switching (STS), we fabricated current perpendicular to plane giant magnetoresistance (CPP-GMR) and tunnel magnetoresistance (TMR) devices with Co/Pt multilayers for free layers and investigated the MR properties, the STS characteristics, and the Kerr effects. A Kerr hysteresis loop was clearly observed in the CPP-GMR device, which was 125 Ã— 180 nm². Full magnetization reversal of the Co/Pt multilayered film by spin transfer torque was demonstrated for a CPP-GMR device with a Cu-based top electrode. On the other hand, there was hardly any resistance change in a CPP-GMR with a transparent top electrode due to the low MR ratio of the device. A TMR stack with a Ag buffer layer showed a strong perpendicular magnetic anisotropy. An MR curve was detected for a TMR device with a transparent top electrode.

Keywords

Kerr magneto-optical effect; cobalt; giant magnetoresistance; magnetic hysteresis; magnetic multilayers; magnetic switching; magnetisation reversal; magneto-optical devices; perpendicular magnetic anisotropy; platinum; spatial light modulators; transparency; tunnelling magnetoresistance; Ag; Ag buffer layer; CPP-GMR; Co-Pt; Co/Pt multilayered films; Co/Pt multilayered free layers; Cu-based top electrode; Kerr hysteresis loop; MR Properties; current perpendicular to plane giant magnetoresistance; full magnetization reversal; magneto-optical Kerr effect; magnetooptical light modulation device; perpendicular magnetic anisotropy; spatial light modulators; spin transfer switching; spin transfer torque; submicron size; transparent top electrode; tunnel magnetoresistance devices; Electrodes; Magnetic films; Magnetic modulators; Magnetic properties; Magnetic switching; Magnetooptic devices; Magnetooptic effects; Optical modulation; Perpendicular magnetic anisotropy; Tunneling magnetoresistance; Current perpendicular to plane giant magnetoresistance (CPP-GMR); perpendicular magnetic anisotropy; spin transfer torque; tunnel magnetoresistance (TMR);

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2010.2042931

Filename

5467557