Polarization Response and Thermally Stimulated Depolarization Current of BaTiO₃‐based Y5V Ceramic Multilayer Capacitors

Abstract

Polarization response and thermally stimulated depolarization current (TSDC) of BaTiO3‐based ceramic multilayer capacitors with Y5V specification were studied. The temperature dependence of dielectric behavior shows that as the dc electric field increases, the polarization response in the whole measurement range (from −125°C to +350°C) is suppressed. As the temperature rises to about 250°C, dielectric loss significantly increases and has a dependence on dc electric field, due to the leakage behavior at high temperature. According to the hysteresis loops, the calculated electrostatic energy density and energy efficiency are also closely related to polarization‐electric field. Utilizing a fixed measuring polarization condition, two TSDC relaxation peaks are observed and both are associated with oxygen vacancies. It is demonstrated that the weak peak originates from the in‐grain migration of oxygen vacancies and the strong peak with high relaxation temperature is caused by the across grain‐boundary oxygen vacancies. The activation energy estimated for the relaxation of oxygen vacancies across grain boundaries is about 0.78 eV. The main contribution for the leakage behavior is from the across grain‐boundary relaxation of oxygen vacancies. With increasing of temperature and electric field stress, the extrinsic oxygen vacancy defects show more fluent migration, which eventually leads to the resistance degradation and breakdown.

Structure, Microwave Dielectric Properties and Thermally Stimulated Depolarization Currents of (1 − x)Ba0.6Sr0.4La4Ti4O15–xBa5Nb4O15 Solid Solutions

“…Besides the inherent intrinsic loss and structure, Qf value is also contributed by the extrinsic defects in dielectrics, such as defect dipoles, trap charges and space charges, etc . TSDC was applied to analysis the extrinsic microwave loss mechanism.…”

“…Using the methods outlined in detail in references, the activation energies of some clear relaxation peaks are evaluated . Figure shows the fitted activation energy E versus polarization temperature ( T p ) with the different x .…”

“…Thermally stimulated depolarization current (TSDC) measurement may provide information about the type of defects existing in dielectrics, such as defect dipoles, trap charges, and space charges, etc . Typically, the sample can be polarized by a static electric field under a relatively high temperature.…”

“…Then the polarization electric field is removed and the sample is short circuited. As a consequence of heating at a constant rate, the polarization relaxes and a weak current in the external circuit is measured as TSDC …”

Thermally stimulated depolarization currents and dielectric properties of Mg0.95Ca0.05TiO3 filled HDPE composites

“…Utilizing the initial rising method, 29 trap depth (activation energy) can be calculated. The results of HDPE and composites are listed in the last column of Table I and plotted in Fig.4.…”