Dielectric Properties of Y₂O₃ and Nb₂O₅ Co-Doped Barium Titanate Ceramics

Abstract

Conventional solid-state route method was used to prepare barium titanate ceramics doped with Y 2 O 3 and Nb 2 O 5 , Ba(Y 0.5 Nb 0.5 ) x Ti (1- x ) O 3 ( x = 0.02, 0.04, 0.06, 0.08). The X-ray diffraction results confirmed that Y 3+ and Nb 5+ both substitute for Ti 4+ at the B-site of ABO 3 perovskite type structure, and second phase appeared for x = 0.04 and 0.06. With the increases of Y 3+ and Nb 5+ concentrations, peak of dielectric constant of Ba(Y 0.5 Nb 0.5 ) x Ti (1- x ) O 3 ceramics shifts to lower temperature more rapidly than that of BaZr x Ti 1- x O 3 ceramics as the same x content. It was found that Ba(Y 0.5 Nb 0.5 ) 0.06 Ti 0.94 O 3 ceramics has compact structure, better temperature stability of dielectric constant, larger dielectric tunability under DC electric field. The results showed that, the Y 2 O 3 and Nb 2 O 5 doping improved the figure of merit for the BaTiO 3 ceramics.