Incorporation of lanthanide ions into lead titanate

TL;DR

This study investigates how doping lead titanate ceramics with various lanthanide ions affects their structural and ferroelectric properties, revealing size-dependent substitution effects and transition temperature changes.

Contribution

It provides new insights into lanthanide ion incorporation mechanisms and their impact on lead titanate's structural and phase transition behaviors.

Findings

La3+ doping reduces tetragonality and cell volume

Sm3+, Eu3+, Gd3+, Dy3+ partially substitute on B-site

Transition temperature increases with smaller lanthanide ions

Abstract

A series of lanthanide, Ln, ion doped lead titanate ceramics, at 2 and 8 at.%, have been prepared with starting compositions Pb1-3x/2LnxTiO3, Ln = La, Nd, Sm, Eu, Gd, Dy, using a standard ceramic method. Structural, and differential scanning calorimetry, measurements are reported. Doping with La3+ results in a reduction in tetragonality and cell volume; a partial recovery was then observed for the smaller Ln3+ ions and suggests the onset of partial substitution of the rare earth on the B-site. The ferroelectric-paraelectric transition temperature results also consistent with an increased probability the B-site occupation with decreasing ion size.