Electrical conduction and polarization of calcite single crystals

Abstract

The electrical conductivity and polarization properties of calcite single crystals with three orientations, namely, a (00.1) plane perpendicular to the crystallographic c axis (10.0) plane parallel to the crystallographic c axis, and a (10.4) cleavage plane, were studied by both complex impedance and thermally stimulated depolarization current (TSDC) measurements. Conductivities for (00.1)-, (10.0)-, and (10.4)-oriented single calcite crystals at 400–600 °C were 1.16 × 10−7 – 1.05 × 10−5, 7.40 × 10−8 – 4.27 × 10−6, and 4.27 × 10−7 – 2.86 × 10−5 Ω−1 m−1, respectively, and the activation energies for conduction were 112, 103, and 101 kJ mol−1, respectively. The TSDC spectra verified the electrical polarizability of calcite crystals. The activation energy for depolarization, estimated from TSDC spectra, of the (00.1)-, (10.0)-, and (10.4)-oriented calcite substrates were 112, 119, and 114 kJ mol−1, respectively. Considering the correlation between the processes of conduction and electric polarization, we proposed the mechanisms of conduction and polarization in calcite on the assumption of oxide ion transport.