Colossal permittivity and multiple effects in (Zn + Ta) codoped TiO2 ceramics

Abstract

Colossal permittivity (CP) materials are potential for the important applications of device miniaturization and energy storage. In this work, (Zn2+1/3Ta5+2/3)xTi1-xO2 ceramics were fabricated by conventional solid-state method. Large dielectric permittivity (>104) and low tanδ (<0.06) have been attained. This dielectric property shows a high stability in wide temperature (30–200°C) and frequency (20–106 Hz) range. The crystalline structure, microstructure and dielectric properties of ZTTO ceramics were systematically investigated. XPS reveals the formation of electron-pinned defect-dipoles (EPDD) model. In addition, combined with impedance spectroscopy and frequency dependent dielectric constant under DC bias results reveal that colossal permittivity are mainly caused by EPDD model, internal barrier layer capacitance (IBLC) effect, and electrode effect. This work would provide guidance to further researching the colossal permittivity materials.