Study of ordered nano-regions in Pb(Zn1/3Nb2/3)0.915Ti0.085O3 single crystal using Raman spectroscopy

A Raman spectroscopic study was performed on a Pb(Zn1/3Nb2/3)(0.915)Ti0.085O3 crystal to study the ordered nano-regions. The variation of the Raman spectra with temperature in the range from -200 to 1000degreesC clearly exhibited a rhombohedral-tetragonal transition at about 75degreesC followed by a tetragonal-cubic transition at about 175degreesC. The polarization behavior of the 777 cm(-1) octahedral mode suggested the existence of Fm3m nano-ordered regions in Pm3m cubic symmetry. Thermal switching of nano-region polarization was observed above 388degreesC as the thermal energy became greater than the activation energy of nano-clusters and resulted in a decrease in the polarized intensity of the 777 cm(-1) mode. However, both the 51 and 777 cm(-1) modes were observed up to 1000degreesC. Copyright (C) 2003 John Wiley Sons, Ltd.