TELECOMMUNICATIONS AND RADIO ENGINEERING - 2009 Vol. 68,
No 7 		 

 

 

 

Abnormal Magnetic Properties of Granular Co-SiO2/GaAs Nanostructures at the Percolation Threshold Region

M.K. Khodzitskiy, T.V. Bagmut, and S.I. Tarapov
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkiv 61085, Ukraine

I.G. Shipkova
National Technical University “Kharkiv Polytechnical Institute”,
21, Frunze St., Kharkiv, 61002, Ukraine

L.V. Lutsev
Research Institute 'Ferrite-Domen',
8, Chernigovskaya Street, St Petersburg, 196084, Russia


Stognij and N.N. Novitskii
Institute of Solid State and Semiconductor Physics of NASB,
17, P. Brovki Street, Minsk 220072, Belarus

Abstract
Magnetic properties of granular Cox(SiO2)100-x/GaAs nanostructures with the Co contents x=20-85 at.% were studied. Static magnetic properties were examined by high-sensitive vibrating sample magnetometer (VSM) in the magnetic field up to 5 kOe at room temperature. Dynamic magnetic properties were investigated by the electron spin resonance (ESR) method in the frequency range of 25-28 GHz at room temperature. The anomalous local fall in the dependence of the magnetization on the Co concentration of granular nanostructures has been detected in the vicinity of the percolation threshold. According to the proposed theoretical model, the observed peculiarity of the magnetization dependence can be explained by the influence of the semiconductor substrate on the spin polarization of Co particles in the granular film.

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pages 607-620

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