Dipole and interfacial polarization phenomena in natural single-crystal calcite studied by the thermally stimulated depolarization currents method

The low-temperature thermal depolarization spectrum of natural single-crystal calcite exhibits two relaxation mechanisms: the lower temperature (LT) one located at 188 K and the medium temperature (MT) one located at 230 K. Extensive thermally stimulated depolarization current (TSDC) experiments proved that the LT band is related to the rotation of defect dipoles, while the MT one to the interfacial polarization. A theoretical quantitative model, which involves the SiO2 inclusions in the matrix, is developed and successfully interprets the appearance and the behavior of the MT band. [S0163-1829(98)02940-3].