Aging behavior of ni-electrode multilayer ceramic capacitors with x7r characteristics

Abstract

Capacitance aging under dc field has been studiedon BaTiO3-based dielectrics with X7R characteristics for multilayer ceramic capacitors with Ni internal electrodes. Capacitance change strongly depends on additives and firing conditions as well as microstructure. Aging behavior under no dc field is well explained by Richter's relaxation curve. On the other hand, aging under dc field cannot be fitted by Richter's curve. Therefore, a new model which assumes two factors that affect relaxation is proposed. According to the new model, capacitance changes in two stages, short-term and long-term relaxations. Capacitance change in short-term relaxation strongly depends on applied dc field. On the contrary, that of long-term relaxation does not depend on dc field. © 1995 The Japan Society of Applied Physics.