Temperature dependent Raman scattering study of order-disorder lead zinc niobate

Abstract

Raman spectra have been measured in lead zinc niobate (PZN)- lead titanate (PT) solid solution single crystals (facets undefined) as functions of temperature (70K–580K) and composition (x ' 0.02, 0.085, and 0.11) into its parallel and perpendicular configurations. The presence of complex multiband Raman spectra is inconsistent with Pm3m space group symmetry and is an indication of short-range ordering on the B-site. Raman bandwidths are substantially large and nearly independent of temperature indicating a static structural disorder rather than a dynamic dipolar disorder. No soft mode like behavior is observed in the measured frequency range. Abrupt change in wavenumber (frequency) and width of certain bending mode (270 cm−1) at 410 K (140°C) is interpreted as an evidence for a reversible structural phase transition (C-R) at this temperature. The sequence of structural phase transition of C-T-R was also observed in one of the compositions (x ' 0.085), though diffuse and less obvious. In addition, the spectroscopic properties are found to be dependent on the substitution of titanium ion reflecting in the temperature of phase transition.