Defect dipole relaxation in polycrystalline dolomite [CaMg(CO3)2

Abstract

The thermally stimulated depolarization current or ionic thermocurrent technique detects two low-temperature bands with maxima at 140 and 188 K, respectively. The choice of proper polarizing conditions, to inhibit the formation of space-charge polarization, permits the accurate study of the low-temperature mechanisms. The extensive dielectric characterization shows that the relaxation mechanisms are related to homogeneous polarization processes and most likely originate from dipolar centers. The thermal treatments indicate that the centers are probably defect dipole agglomerates. The energy parameters for dielectric relaxation are also evaluated. \textcopyright{} 1996 The American Physical Society.