The aging properties of 0.01mol% Mn-doped Ba0.8Sr0.2TiO3 ceramics were

investigated from 30C to 400C at various frequencies. Decreases in ε′(T) of the

aged sample compared to the fresh one around the tetragonal–cubic transition and

in the regime of diffusion were observed. The activation energy Ea=1.25eV

obtained from the J–T loop at zero electric field indicates that oxygen vacancies

dominate in the aging. The symmetry-conforming principle of point defects was

employed to explain the time and temperature dependence of aging in the dielectric

constant and double/constricted P–E loops of the samples aged in the paraelectric

and ferroelectric state.

Oxygen Vacancy-Induced Aging of Mn-Doped Ba0.8Sr0.2TiO3 Ceramics in

Paraelectric and Ferroelectric State. Z.Li, H.Fan: Solid State Ionics, 2009,

180[20-22], 1139-42