Fabrication and properties of non-stoichiometric Tb2(Hf1−xTbx)2O7−x magneto-optical ceramics

Abstract

AbstractNon-stoichiometric Tb2(Hf1−xTbx)2O7−x (x = −0.07–0.45) magneto-optical ceramics were fabricated by solid-state reactive sintering in vacuum combined with hot isostatic pressing (HIP) post-treatment without any sintering aids. The phase composition, densification process, microstructure, optical transmittance, and Verdet constant of Tb2(Hf1−xTbx)2O7−x ceramics were investigated. The in-line transmittance of (Tb0.93Hf0.07)2Hf2O7.07 ceramics with a thickness of 2.0 mm reaches 74.6% at 1064 nm. The Verdet constant of Tb2(Hf1−xTbx)2O7−x ceramics is −153.4, −155.8, and −181.2 rad/(T·m) at the wavelength of 633 nm when x = −0.07, 0, and 0.1, respectively. The Verdet constant increases with the increase of Tb content, and these values are higher than that of the commercial Tb3Ga5O12 crystal, indicating that non-stoichiometric Tb2(Hf1−xTbx)2O7−x ceramics have a great potential for the application in Faraday isolators.