2024-03-28T10:48:36Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1364242016-09-08T01:32:57Zcom_10261_36com_10261_4col_10261_289
00925njm 22002777a 4500
dc
Perna, Paolo
author
Muñoz Sánchez, Manuel
author
Miranda, Rodolfo
author
2012-04
The giant-magnetoresistance (GMR) effect found in multilayered structures composed by
ferromagnetic (FM) layers separated by non-magnetic spacers has attracted sustained interest over the past
decades for both fundamental and technological reasons [1,2]. Such effect consists in a significant change of
the electrical resistance depending on the relative magnetization orientation of the FM layers, which could
originate from spin-dependent scattering processes of the electrons traveling across the structure [3]. Even
though it is commonly assumed that the MR depends on the magnetic anisotropy of multilayer structures, a
comprehensive description of the magneto-resistive behavior related to the magnetization reversal is still
lacking. Experiments just relies in either magnetization (usually parallel component) or MR curves measured
independently for a given applied field angle, normally close to the easy axis (e.a.) direction. Here, we present
a detailed study of the angular dependence of both magneto-resistive and magnetization reversal properties
in a exchange-biased spin valve structure [4], by using a new experimental set-up that allows us to measure
simultaneously magneto-resistance and vectorial-resolved Kerr [5] hysteresis loops, i.e., including MR and
in-plane parallel and perpendicular magnetization components, at different applied field angles in the whole
angular range. We advance towards a microscopic understanding of the MR properties by showing that their
angular dependence leaves distinct fingerprints, which are directly related to their magnetization reversal
processes.
For instance, reversible and irreversible transitions are similar in both MR and vectorial-resolve magnetization
curves. Well-defined MR-plateaus are observed around the e.a. direction whereas just reversible MR
transitions are found around the hard axis (h.a.) direction. The MR-plateau value decreases as the magnetic
field is misaligned with respect to the e.a. and the maximum of MR decreases approaching the h.a. The
results directly show that the different magneto-resistive behaviors originate from the magnetic anisotropy of
the structure, which ultimately depends on the relative magnetization orientation of the FM layers.
References:
[1] M.N. Baibich, J.M. Broto, A. Fert, F. Nguyen Van Dau, F. Petroff, P. Eitenne, G. Greuzet, A. Friederich, and
J. Chazelas, Phys. Rev. Lett. 61, 2472 (1988); G. Binash, P. Grunberg, F. Saurenbach, and W. Zinn, Phys.
Rev. B 39, 4828 (1989).
[2] G. A. Prinz, Science 282, 1660 (1998).
[3] A. Fert, Angew. Chem. Int. Ed. 47, 5956 (2008); C. Chappert, A. Fert and F. N. Van Dau, Nature Mater.
813, 6 (2007).
[4] B. Dieny, V.S. Speriosu, S.S.P. Parkin, B.A. Gurney, D.R. Wilhoit, and D. Mauri, Phys. Rev. B 43, 1297
(1991).
MRS Spring Meeting & Exhibit (2012)
http://hdl.handle.net/10261/136424
Performance/Functionality/spintronic
Properties/Magnetic/magnetooptic
Properties/Transport/magnetoresistance (transport)
Simultaneous study of magnetization reversal and magneto-resistive properties in spin-valve