Research article

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

¹ School of Materials Science and Engineering, Ocean University of China, Qingdao 266100, PR China
² Shandong Tongfang Luying Electronic Co., Ltd, Linyi 276300, PR China
³ Institute of Marine Materials Science and Engineering, Shanghai Maritime University, Shanghai 201306, PR China

^* e-mail: zcshi@ouc.edu.cn
^** e-mail: 13562940122@126.com

Received: 16 October 2023
Accepted: 30 April 2024
Published online: 3 July 2024

Abstract

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, (Ba_100−xSr_x)(Ti_100−yZr_y)O₃ composite ceramics are fabricated via the solid sintering method. Surprisingly, the dielectric properties of (Ba_100−xSr_x)(Ti_100−yZr_y)O₃ 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 °C, 1 kHz), along with a high breakdown strength of 84.47 kV/cm is achieved in (Ba₉₀Sr₁₀)(Ti₉₀Zr₁₀)O₃ composite ceramics, which are 2144% and 13 % higher than those of (Ba₉₉Sr₁)(Ti₉₉Zr₁)O₃ 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 (Ba_100−xSr_x)(Ti_100−yZr_y)O₃ composite ceramics have broad application prospects in electronics and electrostatic energy storage capacitors.