Grain Size and Temperature Dependence of Electrical Breakdown in BaTiO₃Ceramic

Abstract

Electrical breakdown phenomena of barium titanate ceramic were studied. Sintered ceramic samples made from high purity BaTiO 3 powders with varying particle sizes were obtained by heat treatment in the range of 1280∼1400 • C. The resulting average grain size value changed from 1.3 µm to over 40 µm. After applying gold electrodes, electrical breakdown test was performed at two different temperatures, i.e. room temperature and 150 • C, for samples immersed in silicone oil bath using 60 kV dc power supply with voltage rate of 500 V/s. As a consequence, both intrinsic and extrinsic failure mechanisms were identified and commonly occurred in these materials. Effects of sample thickness and grain size on breakdown strength are discussed in some details. Crystalline state, i.e. either ferroelectric tetragonal phase or paraelectric cubic phase, showed great influence on intrinsic breakdown mode. A qualitative model for intergranular and transgranular mechanisms is proposed.

Electrocaloric temperature change constrained by the dielectric strength

“…Xu et al [24] simply attributed this relationship to the fact that more grain boundaries represent a longer path of least resistance, which requires higher voltage for the breakdown to happen. According to Lee et al [22] less grain boundary area (larger grains) leads to an increase in the voltage drop on each grain boundary; hence, leading to a lower apparent dielectric strength of each grain boundary.…”

Click-In Ferroelectric Nanoparticles for Dielectric Energy Storage

“…[15][16][17][18][19] Solid state dielectric capacitors are the only energy storage method that have intrinsically high power densities and the desirable wear properties, making them an attractive candidate for further development. [20][21][22][23][24][25][26][27] The major drawback for dielectric capacitors is their relatively low energy density. The energy density of dielectric capacitors is approximately 3 orders of magnitude less than that of Li-ion technologies.…”

“…The energy density of dielectric capacitors is approximately 3 orders of magnitude less than that of Li-ion technologies. Improving the energy density of dielectric capacitors has been of particular interest over the past 10 years focusing on high dielectric constant ceramics, [26][27][28][29][30][31][32][33][34][35][36][37][38][39] high breakdown polymers, [40][41][42][43][44][45][46][47][48][49][50][51] and composites of these materials. 24,32,[52][53][54][55][56][57][58][59][60][61] Research on dielectric capacitors aims to improve the two material properties that dictate the energy density of a device (i.e.…”

Электрокалорический Эффект В Триглицинсульфате В Равновесных И Неравновесных Термодинамических Условиях

“…Одной из основных целей такого рода работ является поиск путей создания новых и модернизации известных материалов, позволяющих получить большие значения абсолютных величин интенсивного T AD и экстенсив-ного S ECE эффектов. Однако при этом неизбежной оказывается необходимость в больших напряженностях электрического поля E, нередко приводящих к электри-ческому пробою объемных электрокалорических (EC) элементов [11]. Последнюю проблему пытаются решить путем использования пленочных сегнетоэлектрических элементов, в которых большие величины E могут быть реализованы при невысоких напряжениях [12,13].…”