Thermal and spin-torque noise in CPP (TMR and/or GMR) read sensors

Author

Smith, Neil ; Katine, J.A. ; Childress, Jeffrey R. ; Carey, Matthew J.

Author_Institution

Hitachi Global Storage Technol., San Jose, CA, USA

Volume

42

Issue

2

fYear

2006

Firstpage

114

Lastpage

119

Abstract

This paper considers magnetization fluctuations (mag-noise) in current-perpendicular-to-plane (CPP) read sensors, due to either thermal fluctuations or spin-torque induced instability. The former are relevant to both tunneling (TMR) and giant-magnetoresistance (GMR) devices, the latter a potentially more serious limitation most relevant to all-metal GMR sensors. Discussion of thermal mag-noise is here treated by micromagnetic simulation. Discussion of spin-torque instability includes analytical modeling combined with experimental measurements.

Keywords

giant magnetoresistance; magnetic heads; magnetic recording noise; magnetic sensors; micromagnetics; perpendicular magnetic recording; thermal noise; tunnelling magnetoresistance; GMR sensors; current-perpendicular-to-plane read sensors; giant-magnetoresistance devices; magnetization fluctuations; micromagnetic simulation; spin-torque instability; spin-torque noise; thermal mag-noise; thermal noise; tunneling magnetoresistance devices; Fluctuations; Giant magnetoresistance; Magnetic analysis; Magnetic anisotropy; Magnetic heads; Magnetic sensors; Magnetization; Thermal sensors; Tunneling magnetoresistance; Voltage; Current-perpendicular-to-plane; giant magnetoresistance; read head; spin-torque;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2005.861783

Filename

1580660