Optimization of Dielectric Properties of Glass Added Ba_xSr_1-xTiO₃ Ceramics for Pulsed Power Applications

Abstract

BaxSr1-xTiO3 (0.2≤x≤0.5) ceramics with 10 vol% BaO-SiO2-B2O3 glass addition were prepared. The microstructure and dielectric properties were investigated by XRD, SEM, ferroelectric tester and impedance analyzer. The results show that with the decrease of x, the pulse breakdown strength of the samples is increased, and the dielectric constant and dielectric loss is decreased gradually. In the frequency from 10 kHz to 20 MHz, the dielectric constant of all the samples show good frequency stability. For x=0.2, the samples exhibit high breakdown strength of 37.7 kV/mm, moderate dielectric constant of 311 and low dielectric loss of 5×10-4,which is a promising dielectric for pulsed power applications.

Microstructures and dielectric properties of Ba0.4Sr0.6TiO3 ceramics with BaO–TiO2–SiO2 glass–ceramics addition

“…Besides a high E b , a large variation of polarization is another key factor, which is related to the dielectric constant to a certain extent [5]. Considering the two factors, the addition of glasses to BST ceramics has widely been investigated for achieving high energy density recently [7][8][9][10][11][12][13][14][15][16].…”

“…The glass additives can decrease the sintering temperature and modify the microstructure of BST, the improvement of breakdown strength can be attributed to the reduction of grain size, the decrease of porosity, and a more homogeneous microstructure [13][14][15][16]. Among various systems of glasses, B 2 O 3 -SiO 2 -based glasses, such as BaO-B 2 O 3 -SiO 2 , SrO-B 2 O 3 -SiO 2 , CaO-B 2 O 3 -SiO 2 [8][9][10][11][12], possess higher breakdown strength and well wetting with BST ceramics, which should be effective additives in improving the energy storage density of BST ceramics.…”