Room-temperature ferromagnetism in Zn{sub 1-x}Co{sub x}O magnetic semiconductors prepared by sputtering

Journal Article · Wed Jun 15 00:00:00 EDT 2005 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1937478· OSTI ID:20711763

Dinia, A; Schmerber, G; Meny, C; Pierron-Bohnes, V; Beaurepaire, E ^[1]

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1. Institut de Physique et Chimie des Materiaux de Strasbourg IPCMS, Centre National de la Recherche Scientifique CNRS-United Mixte de Recherche UMR 7504, Universite Louis Pasteur - ULP -Ecole Europeenne de Chimie, Polymeres et Materiaux ECPM, 23 rue du Loess, F-67034 Strasbourg (France)

We have used magnetron cosputtering to grow Zn{sub 1-x}Co{sub x}O magnetic dilute semiconductors. The growth has been performed on SiO{sub 2}/Si and Al{sub 2}O{sub 3}(0001) substrates. The Co concentration has been varied between 0.1 and 0.25 and the substrate temperature between room temperature and 600 deg. C. X-ray diffraction analysis has shown that for the films grown on Si substrates the structural quality of the film is improved by increasing the growth temperature and/or postgrowth annealing. The films are textured with c axis of the wurtzite structure along the growth direction. However, for the films grown on Al{sub 2}O{sub 3} substrate quasi-epitaxial films have been obtained for 600 deg. C substrate temperature. Magnetization measurements have shown that the ferromagnetism is directly correlated to the structural quality and appears by increasing the growth temperature and/or postgrowth annealing. Moreover, for the highly textured film a clear magnetic perpendicular anisotropy has been evidenced with the easy magnetization axis along the growth direction. To evidence the intrinsic nature of the ferromagnetism in the films, transmission optical measurements have been used. They show three absorption bands that are characteristics of d-d transitions of tetrahedrally coordinated Co{sup 2+}. This has been supported by nuclear magnetic resonance and magnetic thermal variation.

• OSTI ID: 20711763
• Journal Information: Journal of Applied Physics, Vol. 97, Issue 12; Other Information: DOI: 10.1063/1.1937478; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
ANISOTROPY
ANNEALING
COBALT COMPOUNDS
COBALT IONS
CRYSTAL GROWTH
DEPOSITION
EPITAXY
FERROMAGNETISM
MAGNETIC SEMICONDUCTORS
MAGNETIZATION
MAGNETRONS
NUCLEAR MAGNETIC RESONANCE
SILICON OXIDES
SPUTTERING
TEMPERATURE RANGE 0273-0400 K
TEXTURE
THIN FILMS
X-RAY DIFFRACTION
ZINC COMPOUNDS