Field enhanced bulk conductivity of acceptor-doped BaTi1-x CaxO3-x ceramics

Abstract

The electrical properties of Ca-doped BaTiO3 are very different when Ca substitutes onto Ba or Ti sites. The p -type semiconductivity of Ti-substituted ceramics increases reversibly by one to two orders of magnitude under a dc-bias voltage of ≤ 100 V cm-1, whereas Ba-substituted ceramics show little sensitivity to a dc bias. This increase in BaTi 1-x CaxO3-x, studied over the temperature range 150-600 °C, is independent of electrode material and atmosphere and is attributed to ionization of underbonded O2- ions adjacent to acceptor-doped Ca2+ ions. © 2010 American Institute of Physics.