Effect of Nb doping on the hysteresis parameters of sol-gel derived [formula omitted] thin films

Abstract

The effect of Nb on the hysteresis parameters of sol-gel Pb 1.1− x 2 (Zr 0.53Ti 0.47) 1−xNb xO 3 (x = 0.0 – 0.05, increments of 0.01) thin films is reported. Two sets of (111) textured films, rapid annealed at 600 and 650°C, were studied. The degree of texture and grain size as a function of Nb was analogous for the two sets. Surface coverage by a pyrochlore phase increased with Nb addition, however its quantity and distribution was determined by the annealing temperature, being less for the 650°C set of films. For the two sets a strong continuous decay of the remanent and maximum polarizations, and the slope at the coercive field, ( dP dE ) Ec , was observed with increasing Nb. The remanent polarization was reduced by a scaling factor at any given field, yielding no changes in the saturation profiles as a function of doping. The difference of the maximum minus remanent polarization and the width of the loop were not influenced by Nb at any given field. A linear increase in coercive field asymmetry (up to 40 kV/cm) was observed with Nb addition, yet was field independent and thus electrostatic in origin. A methodology for isolation of Nb induced microstructural effects from bulk or defect modifications was developed. The comprehensive set of hysteresis parameters required for such an analysis is presented here.