Study of structural phase transitions in solid-solution (1 −x)PZN-xPT relaxor ferroelectric using Raman scattering

Abstract

We investigated the solid-solution (1 − x)Pb(Zn1/3Nb2/3)O3–xPbTiO3 relaxors by means of Raman spectroscopy. A detailed temperature-dependent study in the range 70–580 K was carried out on (1 − x)PZN–xPT relaxors with compositions x = 0.02 and 0.05 using Raman scattering under different optical and electric field variables, namely the polarization and the crystallographic direction, respectively. Qualitatively, subtle differences in the Raman spectra for both PZN–2%PT and PZN–5%PT samples were detected. This is because the latter sample was poled along the 〈001〉 direction and may be due to the residual electric field. It was established that the sharp structural phase transition at or in the vicinity of 420–460 K is the first-order transition by fitting two of the ‘order parameters’ (mode wavenumber and bandwidth) for one of the representative Raman bands at 277 cm−1. Copyright © 2000 John Wiley & Sons, Ltd.