Effect of Ni doping on ferroelectric and dielectric properties of strontium barium niobate crystals

摘要

The influence of Ni doping on the ferroelectric and dielectric properties have been examined in Sr_(0.61) Ba_(0.39) Nb_O_6 (SBN:61) relaxor crystals. The dopants introduced into SBN:61 crystals promote the switching process by reducing the value of threshold nucleation field, and thus coercive field. We present real-time studies of domain nucleation and growth processes in doped SBN:61 by the nematic liquid crystal (NLC) decoration technique. The broad phase transition and low-frequency dielectric dispersion that are exhibited by doped SBN:61 samples have a strong link to the configuration of the ferroelectrics microdomains, which in turn is strongly determined by Ni ions concentration.