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Title: Reactive sputtering synthesis of Co-CoO/Ag nanogranular and multilayer films containing core-shell particles

Abstract

We present magnetic characterization of two series of samples grown by reactive sputtering of Co and Ag: (i) thin films obtained by cosputtering of these metals at different oxygen pressures, and (ii) Co/Ag multilayer films deposited with fixed Co layer thickness (1.1 nm) and oxygen pressure (2x10{sup -5} mbar), and varying Ag layer thickness t{sub Ag}. For certain preparation conditions the samples obtained with both synthesis methods consist of a dispersion of core-shell Co-CoO nanoparticles embedded in a Ag matrix. Regarding series (i), it is remarkable that the interesting core-shell/matrix structure, suggested by exchange-bias and giant magnetoresistance properties, could be achieved using the simple one-step technique of reactive cosputtering. In series (ii), the exchange-bias and coercivity fields strongly depend on the spacer layer thickness for t{sub Ag}<4 nm, and then become roughly thickness independent. A discontinuous-continuous transition in the silver layers with increasing t{sub Ag}, similar to that observed in a previous study, is hypothesized as the origin of the behavior in both fields.

Authors:
; ; ; ; ; ; ;  [1]
  1. Departamento de Fisica Aplicada, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)
Publication Date:
OSTI Identifier:
20982859
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 101; Journal Issue: 9; Conference: 10. joint MMM/INTERMAG conference, Baltimore, MD (United States), 7-11 Jan 2007; Other Information: DOI: 10.1063/1.2671688; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COBALT; COBALT OXIDES; COERCIVE FORCE; DEPOSITION; DISPERSIONS; EXCHANGE INTERACTIONS; FERROMAGNETIC MATERIALS; GRANULAR MATERIALS; LAYERS; MAGNETORESISTANCE; NANOSTRUCTURES; OXYGEN; PARTICLES; PHASE TRANSFORMATIONS; SILVER; SPUTTERING; THICKNESS; THIN FILMS

Citation Formats

Munoz, T., De Toro, J. A., Normile, P. S., Andres, J. P., Gonzalez, J. A., Muniz, P., Barbero, A. J., and Riveiro, J. M. Reactive sputtering synthesis of Co-CoO/Ag nanogranular and multilayer films containing core-shell particles. United States: N. p., 2007. Web. doi:10.1063/1.2671688.
Munoz, T., De Toro, J. A., Normile, P. S., Andres, J. P., Gonzalez, J. A., Muniz, P., Barbero, A. J., & Riveiro, J. M. Reactive sputtering synthesis of Co-CoO/Ag nanogranular and multilayer films containing core-shell particles. United States. doi:10.1063/1.2671688.
Munoz, T., De Toro, J. A., Normile, P. S., Andres, J. P., Gonzalez, J. A., Muniz, P., Barbero, A. J., and Riveiro, J. M. Tue . "Reactive sputtering synthesis of Co-CoO/Ag nanogranular and multilayer films containing core-shell particles". United States. doi:10.1063/1.2671688.
@article{osti_20982859,
title = {Reactive sputtering synthesis of Co-CoO/Ag nanogranular and multilayer films containing core-shell particles},
author = {Munoz, T. and De Toro, J. A. and Normile, P. S. and Andres, J. P. and Gonzalez, J. A. and Muniz, P. and Barbero, A. J. and Riveiro, J. M.},
abstractNote = {We present magnetic characterization of two series of samples grown by reactive sputtering of Co and Ag: (i) thin films obtained by cosputtering of these metals at different oxygen pressures, and (ii) Co/Ag multilayer films deposited with fixed Co layer thickness (1.1 nm) and oxygen pressure (2x10{sup -5} mbar), and varying Ag layer thickness t{sub Ag}. For certain preparation conditions the samples obtained with both synthesis methods consist of a dispersion of core-shell Co-CoO nanoparticles embedded in a Ag matrix. Regarding series (i), it is remarkable that the interesting core-shell/matrix structure, suggested by exchange-bias and giant magnetoresistance properties, could be achieved using the simple one-step technique of reactive cosputtering. In series (ii), the exchange-bias and coercivity fields strongly depend on the spacer layer thickness for t{sub Ag}<4 nm, and then become roughly thickness independent. A discontinuous-continuous transition in the silver layers with increasing t{sub Ag}, similar to that observed in a previous study, is hypothesized as the origin of the behavior in both fields.},
doi = {10.1063/1.2671688},
journal = {Journal of Applied Physics},
number = 9,
volume = 101,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}
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