The temperature dependence of dielectric properties of Bi-doped ceramics with (Ba0.95Bi0.05)0.9Sr0.1TiO3−δ and (Ba0.9Bi0.1)0.9Sr0.1TiO3−δ (abbreviated as BBST5 and BBST10, respectively) was investigated, comparing with non-doped Ba0.9Sr0.1TiO3 (abbreviated as BST) ceramics. The dielectric relaxation behavior above 150 C was observed in BBST5 and BBST10 ceramics with two broad dielectric loss peaks, which was very different from the BST ceramics with only one broad loss peak. The universal dielectric response (UDR) to the relaxation and P–E hysteresis loops, as well as J–E properties was studied. The activation energy Ea with 0.83, 0.84eV in the first dielectric loss peak P1 and 0.60, 0.65eV in the second loss peak P2, and the exponent s in the UDR law decreasing with the increasing temperatures for BBST5 and BBST10 ceramics indicated that oxygen vacancies associated with electrons were responsible for the dielectric relaxation.

Relaxation Associated with the Synergetic Oxygen Vacancies and Electrons in (Ba1−xBix)0.9Sr0.1TiO3−δ Ceramics. Z.Li, H.Fan: Journal of Applied Physics, 2010, 108[3], 034103