Incorporation of Yttrium in Barium Titanate Ceramics

Abstract

In this work, X‐ray diffractometry and scanning electron microscopy techniques were used to study the incorporation of yttrium in BaTiO 3 , with the following nominal compositions: (Ba 1‐ x Y x )TiO 3 (0.015 ≤ to x ≤ to 0.08), (Ba 1‐ x Y x )Ti 1‐ x /4 ‐(□ Ti ) x /4 O 3 (0.005 ≤ to x ≤ to 0.1), and Ba(Ti 1‐ y Y y )O 3‐delta (0.028 ≤ to y ≤ to 0.258). The phase assemblage and the lattice parameters indicated a slight solubility (∼1.5 at.%) of yttrium at the Ba sites at 1440°C but a high solubility (∼12.2 at.%) of yttrium at the Ti sites at 1515°C. When BaTiO 3 was heavily doped with yttrium at the Ti sites (a yttrium concentration ( y ) of <0.059), the crystallographic structure was tetragonal, whereas for y greater than equal to 0.059, the crystallographic structure was cubic.