Enhanced electrical reliability of Zr‐doped BaTiO3 nanoceramics: First‐principle calculations and experimental studies

Abstract

AbstractWith the miniaturization of multilayer ceramic capacitors (MLCCs) and the increase of electric field on single‐layer dielectrics, it is essential for the development of nanograin high‐reliability dielectric materials. In this work, Zr‐doped BaTiO3‐based ceramics with an average grain size of 130–150 nm were prepared by a chemical coating method. The effects and intrinsic mechanisms of Zr concentration on microstructure, dielectric properties, and reliability were systematically investigated by theoretical calculations and experiments. Zr additives lower the migration barrier of the dopants, which consequently contributes to the formation of thick shell layers in the core‐shell structure and grain growth, affecting the temperature stability and DC bias characteristics of the dielectric constant. Owing to the large change rate of the Zr–O bond length, the introduction of Zr increases the migration barrier of oxygen vacancies. However, the decrease in the effective doping concentration of the shell part and the reduction in the number of grain boundaries of ceramics with high Zr content have a weakening effect on the inhibition of oxygen vacancy migration. An appropriate amount of Zr doping can adjust the dielectric properties and improve the reliability of BaTiO3‐based ceramics. This study provides a theoretical reference for the design of high‐quality MLCCs.