Study of high frequency dielectric response of AgNb_xTa_1−xO₃ mixed system for x = 0.65, 0.82 and 1

Abstract

The quasi-elastic diffusion measured near the specific M2-M3 phase transition in the AgTa_1−xNb_xO₃ system is described by a modified Debye relaxational function from which dielectric dispersion can be calculated in the 1 to 100 cm⁻¹ frequency range. An alternative description of the low-frequency Raman spectra, using Barker's formula is proposed in order to explain the structural phase transition.