Effect of the unit-Cell volume variation on the ferroelectricity in barium-Doped Lead zirconate ceramics

Abstract

The effect caused by barium substitution in Pb-sublattice on the antiferro-ferro-paraelectric phase transitions sequence is Raman spectroscopically evidenced and discussed for the (Pb_1-xBa_x)ZrO₃ solid solution. With progressive increasing of barium content, the amount of the antiferroelectric phase decreases in respect to the neighboring ferroelectric phase. At high barium content and/or high temperature an intermediate phase, admixture of ferroelectric and paraelectric phases, occurs reflecting the very diffuse character of the phase transition. A special focus was on the analysis of the origin of the induced ferroelectricity. The appearance of ferroelectric and mixed phases is explained in the term of change in either chemical nature of A-O and B-O bonds or B-perovskite off-centre positions. Both two effects are found to be a consequence of the unit-cell volume variation effect that is expected to have a control on the induced ferroelectricity

Key Words:

• Lead zirconate
• Raman spectroscopy
• phase transition
• ferroelectricity
• polarizability