GMR Spin Valve with alternating in-plane and out-of-plane magnetic anisotropy

Bogdan Szymański ,  Feliks Stobiecki ,  Maciej Urbaniak 

Polish Academy of Sciences, Institute of Molecular Physics, Mariana Smoluchowskiego 17, Poznań 60-179, Poland

Abstract

In this paper a new type of spin valve (SV) structure is proposed. It consists of ferromagnetic layers, with in-plane (F1) and out-of-plane (F2) anisotropy, separated by nonmagnetic spacer (S). When the magnetic field H is applied perpendicularly to the surface of the (F1/S/F2/S) SV it stabilizes the magnetization direction of the layers with perpendicular anisotropy and forces a rotation of the magnetization direction of the layers with easy plane anisotropy. This situation is reversed for the magnetic field applied parallel to the film surface. The magnetization reversal results in the giant magnetoresistance (GMR) characterized by the linear R(H) dependence in a wide range of magnetic field H.

To realize the idea of the SV we have chosen thin Co layers sandwiched between Au as layers with perpendicular anisotropy (F2). Our measurements proved that Co layers possess a perpendicular anisotropy for 0.4<tCo<1.5 nm and in-plane anisotropy for tCo>1.8 nm. We have found that for Co thickness 0.6<tCo<0.8 nm the effective perpendicular anisotropy is relatively strong. It does not change appreciably in the temperature range from 100 to 423K and is resistant to a low temperature annealing, i.e., Tanneal<450K. As ferromagnetic layers with in-plane anisotropy (F1) we have applied Ni-Fe (tNiFe=2 nm) or Co with thickness tCo>1.8 nm. For both types of structures, i.e., [NiFe1/Au/Co2/Au]N and [Co1/Au/Co2/Au]N multilayers (N is number of repetition), deposited by the magnetron sputtering, the GMR effect of up to 8% at RT was observed. Moreover, due to the considerable simplification, the Co1/Au/Co2/Au structures are preferred for applications (only two materials are required).

Legal notice
  • Legal notice:

    Copyrighted materials, (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced, stored in or introduced into a retrieval or caching system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording or otherwise), or for any purpose, without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: http://science24.com/paper/3766 must be provided.

 

Related papers
  1. Magnetic anisotropy of Co films annealed by laser pulses
  2. Magnetic anisotropy of ultrathin cobalt in Au/Co/Si/Au structures with variable Si thickness.
  3. Spacer layer properties in antiferromagneticaly coupled Fe/SixFe1-x
  4. Interlayer coupling in Ni-Fe/Au/Co/Au multilayers
  5. Moessbauer spectroscopy, interlayer coupling and magnetoresistance of irradiated Fe/Cr multilayers

Presentation: poster at E-MRS Fall Meeting 2005, Symposium D, by Bogdan Szymański
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-05-25 09:38
Revised:   2009-06-07 00:44
Google
 
Web science24.com
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine