Raman spectroscopy and magnetic properties of bulk ZnO:Co single crystal.

Goiran Michel 2Marius Millot 3Jesus Gonzalez 3Z. Golacki 1Jean Marc Broto 2Harison Rakoto 2

1. Polish Academy of Sciences, Institute of Physics, al. Lotników 32/46, Warszawa 02-668, Poland
2. Laboratoire National des Champs Magnétiques Pulsés, av. de Rangueil, Toulouse 31423, France
3. Centro de Estudios de Semiconductores, Universidad de los Andes, Merida, Venezuela

Abstract

We report on the investigation of structural and magnetic properties of the cobalt based diluted magnetic semiconductor with wurtzite structure: Zn1-xCoxO. Single crystals were grown by chemical vapour transport using chlorine as the transporting agent at a growth temperature of 900C. From the Raman measurements in the temperature range 10-300 K on samples with a Co concentration of 5%, we deduce the presence of small quantities of ferromagnetic hcp-Co and also the presence of anti-ferromagnetic CoO impurities. Theses results are in agreement with the behaviour of high magnetic field magnetisation measurements under pulsed fields. High frequency-high field ESR reveal clearly the large crystal field splitting of the energy levels of isolated Co ions as well as satellites lines which originate from Co clusters made of pairs or larger number of neighbouring magnetic ions.

 

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

Submitted: 2005-06-21 15:45
Revised:   2009-06-07 00:44