Relaxor ferroelectric and magnetic properties of Ba6CoNb9O30 ceramics with tungsten bronze structure

Abstract

Dielectric characteristics of Ba6CoNb9O30 tetragonal tungsten bronze ceramics have been evaluated over a broad temperature and frequency range. A broad dielectric peak with strong frequency dispersion is observed at 140–225 K, which well follows the Vogel–Fulcher relationship and indicates the relaxor ferroelectric nature in the present ceramics. The P-E hysteresis loops varying with temperature are consistent with this dielectric relaxation process and provide the further evidence on the relaxor ferroelectric nature. The nonlinear magnetic hysteresis curve is observed in Ba6CoNb9O30 ceramics at 5 K, indicating the soft magnetic behavior which is related to the tetragonal tungsten bronze crystal structure containing magnetic ions of Co3+.