Spin transfer effects in exchange-biased spin-valves for current-perpendicular-to-plane magnetoresistive heads

A. Deac, Kyoung Jin Lee, Y. Liu, O. Redon, M. Li, P. Wang, J. P. Nozières, B. Dieny

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Magnetoresistive heads used in computer disk drives are nowadays based on the giant magnetoresistance of spin-valves. In the present technology, the current is flowing parallel to the interfaces of the spin-valve stack (the so-called "current-in-plane geometry"). However, due to the steady increase in the storage areal density of disk drives, this technology is close to its physical limit. Consequently, more and more efforts are made aiming at using the current-perpendicular-to-plane geometry which offers larger signal amplitude and better spatial resolution. However, new physical effects appear when the current flows perpendicular to the plane in a magnetic multilayer. Of particular interest are the spin transfer effects which were predicted by Slonczewski and Berger in 1996. When they traverse the pinned layer of the spin-valve, the conduction electrons acquire a spin polarization. This spin current exerts a torque on the magnetization of the free layer which induces very peculiar dynamical phenomena. This spin torque can induce the switching of the magnetization of the free layer or the generation of magnetic excitations which contribute to the noise of the head. Therefore in the context of magnetoresistive heads, it is important to understand and master these effects which perturb the behavior of the heads. On the contrary, these effects can be used in a positive way as a new write scheme in non-volatile magnetic random access memories or to generate a steady precession of the magnetization in RF oscillators.

Original languageEnglish
Pages (from-to)42-47
Number of pages6
JournalJournal of Magnetism and Magnetic Materials
Volume290-291 PART 1
DOIs
Publication statusPublished - 2005 Apr 1
Externally publishedYes

Fingerprint

spin exchange
Magnetization
Torque
Magnetic multilayers
Giant magnetoresistance
Electron tubes
Spin polarization
Geometry
magnetization
torque
Data storage equipment
Electrons
random access memory
geometry
precession
conduction electrons
spatial resolution
oscillators
polarization
excitation

Keywords

  • Current-perpendicular-to- plane giant magnetoresistance
  • Magnetoresistive heads
  • Spin torque
  • Spin transfer

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Spin transfer effects in exchange-biased spin-valves for current-perpendicular-to-plane magnetoresistive heads. / Deac, A.; Lee, Kyoung Jin; Liu, Y.; Redon, O.; Li, M.; Wang, P.; Nozières, J. P.; Dieny, B.

In: Journal of Magnetism and Magnetic Materials, Vol. 290-291 PART 1, 01.04.2005, p. 42-47.

Research output: Contribution to journalArticle

Deac, A. ; Lee, Kyoung Jin ; Liu, Y. ; Redon, O. ; Li, M. ; Wang, P. ; Nozières, J. P. ; Dieny, B. / Spin transfer effects in exchange-biased spin-valves for current-perpendicular-to-plane magnetoresistive heads. In: Journal of Magnetism and Magnetic Materials. 2005 ; Vol. 290-291 PART 1. pp. 42-47.
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