A study of phase coexistence and temperature dependent monoclinic to tetragonal phase transition in the multiferroic (1−x)Pb(Fe1/2Nb1/2)O3−xPbTiO3 (x=0.08)

Abstract

The origin of coexistence of tetragonal and monoclinic phases in the morphotropic phase boundary (MPB) region of (1−x)Pb(Fe1/2Nb1/2)O3−xPbTiO3 has been investigated for x=0.08 by synchrotron x-ray powder diffraction in the 10–550 K range. It is shown that the phase coexistence observed at room temperature in the MPB region is essentially due to a first order phase transition between the low temperature monoclinic and high temperature tetragonal phases. This transition is shown to be accompanied with a phase coexistence over a very wide temperature range (ΔT∼200 K) across the room temperature.