A cobalt-copper top spin valve was prepared by thermal evaporation of a stack of ferromagnetic thin films separated by thin layers of the diamagnetic metal, with a cap layer containing an antiferromagnetic (AFM) exchange-biasing material. A nonconventional top AFM layer was used, in order to optimize the multilayer roughness and to avoid electrical interference with metallic layers; it consists of a composite material easily processed by means of optical lithography, basically a polymeric matrix composite with a dispersion of nickel oxide microparticles. Magnetization and magnetoresistance measurements were performed from 4 to 300 K. The measurements of both quantities indicate random pinning action of the top AFM layer, resulting in a small exchange-bias field and in asymmetric magnetization and magnetoresistance curves. A simple model explains the observed physical effects.

Thermally evaporated Cu--Co top spin valve with random exchange bias / Chiolerio, A.; Allia, P.; Chiodoni, A.; Pirri, F.; Celegato, F.; Coisson, Marco. - In: JOURNAL OF APPLIED PHYSICS. - ISSN 0021-8979. - 101:(2007), pp. 123915-1-123915-6. [10.1063/1.2749289]

Thermally evaporated Cu--Co top spin valve with random exchange bias

F. CELEGATO;COISSON, MARCO
2007

Abstract

A cobalt-copper top spin valve was prepared by thermal evaporation of a stack of ferromagnetic thin films separated by thin layers of the diamagnetic metal, with a cap layer containing an antiferromagnetic (AFM) exchange-biasing material. A nonconventional top AFM layer was used, in order to optimize the multilayer roughness and to avoid electrical interference with metallic layers; it consists of a composite material easily processed by means of optical lithography, basically a polymeric matrix composite with a dispersion of nickel oxide microparticles. Magnetization and magnetoresistance measurements were performed from 4 to 300 K. The measurements of both quantities indicate random pinning action of the top AFM layer, resulting in a small exchange-bias field and in asymmetric magnetization and magnetoresistance curves. A simple model explains the observed physical effects.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11696/31123
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