Influence of Doping Style of Yb_2O_3 on Dielectric Character of Ba(Ti_(1-y)Zr_y)O_3 Ceramics

A distinct diversification of dielectric character of Ba(Ti1-yZry)O3 ceramics doped with Yb2O3 in different doping style was observed. When adapted content of Yb2O3 is added after synthesis of Ba(Ti1-yZry)O3, the ferroelectric phase transition points of the ceramics are shifted distinctly, and the dielectric constants at these points increase greatly. This doping method at 1250℃ results in the sample with a high dielectric constant over 25000 at room temperature and according with Y5V specifications. The enhancement of dielectric constant of Ba(Ti1-yZry)O3 caused by the doping of Yb2O3 after synthesis is associated with the localization of electrons produced by donor doping. Doping by Yb2O3 before synthesis results in the sample with a relative low dielectric constant and a weak efficiency of Curie point shifting. This is due to the compensation of localized-electrons by acceptors that introduced by the doping of Yb3+ replacing Ti site in perovskite lattice.