Europhys. Lett.
Volume 66, Number 1, April 2004
Page(s) 48 - 54
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 01 March 2004
Europhys. Lett., 66 (1) , pp. 48-54 (2004)
DOI: 10.1209/epl/i2003-10185-0

Beam fanning used to study thermal disorder and decay of polar structures in the ferroelectric relaxor $\chem{Sr_{0.61}Ba_{0.39}Nb_2O_6}$

M. Goulkov1, O. Shinkarenko1, T. Granzow2, Th. Woike2 and M. Imlau3

1  Institute of Physics - Science Ave. 46, 03650 Kiev-39, Ukraine
2  Institute for Mineralogy, University of Cologne - Cologne, Germany
3  Department of Physics, University Osnabrück - Osnabrück, Germany

(Received 25 April 2003; accepted in final form 8 January 2004)

A new photorefractive approach using the temperature evolution of beam fanning to study the polar structure of the ferroelectric relaxor strontium-barium-niobate (SBN) undergoing the ferroelectric-paraelectric phase transition is proposed. A strong temperature dispersion of the decay of polar structures of different sizes is observed. We compare our results with those obtained by other measurement methods to show their dependence on the size distribution of the polar structures.

42.65.Hw - Phase conjugation; photorefractive and Kerr effects.
77.80.-e - Ferroelectricity and antiferroelectricity.
78.20.Jq - Electrooptical effects.

© EDP Sciences 2004