Effect of Nb5+ ion substitution on the dielectric property of BaTi2O5–Ba6Ti17O40 eutectic prepared by a floating zone method

Abstract

Abstract Ti4+ ions of the materials solidified from the BaTi2O5–Ba6Ti17O40 (BT2–B6T17) eutectic melt were substituted with 0–1.0 at% Nb5+ ions (CNb = 0–1.0 at%) by a floating zone method, and the effects of CNb on the microstructure, permittivity and Curie temperature of the BT2–B6T17 eutectics were studied. The BT2–B6T17 eutectics at CNb = 0–1.0 at% consisted of BaTi2O5 and Ba6Ti17O40. b- and a-axes of BaTi2O5 and Ba6Ti17O40, respectively, were parallel to the growth directions of the BT2–B6T17 eutectic. Ba6Ti17O40 in the BT2–B6T17 eutectic had the rod-like structure parallel to the growth direction in the matrix of BaTi2O5. As CNb increased from 0 to 1.0 at%, the permittivity at room temperature increased from 70 to 214 and the Curie temperature decreased from 748 to 679 K.