Fabrication and properties of Y₂Ti₂O₇ transparent ceramics with excess Y content

Transparent Y₂Ti₂O₇ ceramics with excess Y content were fabricated by solid state reactive sintering in vacuum using Y₂O₃ and TiO₂ powders as the starting materials. Phase composition, microstructure, density and in-line transmittance of the Y₂Ti₂O₇ ceramics were investigated. The detailed results indicated that as Y content increased, the density and in-line transmittance increased at first and then decreased. And the highest in-line transmittance of Y₂Ti₂O₇ ceramics is 49.9% at 1100 nm when the excess amount of Y to Ti is 2%. The effect of Y content on densification process of Y₂Ti₂O₇ ceramics was discussed based on an assumption that oxygen vacancy defects were the dominated defects.