Enhanced dielectric properties of Sr2+ and Zr4+ doped BaTiO3 colossal permittivity metamaterials

BaTiO3, as one of the most important functional materials of perovskite structure, is widely used in the electronic industry. However, the dielectric permittivity of BaTiO3 remains relatively low, which greatly limits its practical application in metamaterials with colossal dielectric permittivity. In this work, (Ba100-xSrx)(Ti100-yZry)O-3 composite ceramics are fabricated via the solid sintering method. Surprisingly, the dielectric properties of (Ba100-xSrx)(Ti100-yZry)O-3 composite ceramic materials are strongly dependent on the occupancy of Sr2+ and Zr4+ at the A-sites and B-sites, respectively. Consequently, via adjusting the doping amount of SrTiO3 and BaZrO3, a greatly enhanced dielectric permittivity of 28287 (65 degrees C, 1 kHz), along with a high breakdown strength of 84.47 kV/cm is achieved in (Ba90Sr10)(Ti90Zr10)O-3 composite ceramics, which are 2144% and 13 % higher than those of (Ba99Sr1)(Ti99Zr1)O-3 composite ceramics, respectively. Moreover, the reasons for the significant increase in dielectric permittivity are identified through finite element simulations, and the breakdown mechanism of composite ceramic materials is explored. This work provides a facile approach to constructing high dielectric permittivity composite ceramics, the (Ba100-xSrx)(Ti100-yZry)O-3 composite ceramics have broad application prospects in electronics and electrostatic energy storage capacitors.