Different dielectric relaxation processes in barium strontium titanate glass-ceramics have been investigated using the thermally stimulated depolarization current (TSDC) technique. The TSDC results obtained from the glass-ceramics polarized under various polarization conditions show the presence of two peaks designated as A and B in ascending order of temperature, respectively. The peak A is determined to be of dipole origin and assumed to be associated with a defect complex. In addition, the peak B is due to space-charge polarization arising from the interface between the crystalline phases and the glass matrix. It is supposed to be associated with the relaxation of oxygen vacancies. The TSDC characteristics demonstrate that the degree of crystallinity in glass-ceramics is a predominant factor in deciding the features of dielectric relaxation mechanisms.
TSDC plots for the BST glass-ceramic samples sintered at various temperatures with the same polarization conditions.