Microwave dielectric properties of Nd:YAG transparent ceramics

Abstract

In order to investigate the microwave dielectric properties of Nd:YAG transparent ceramics, the high pure raw materials were used for the preparation of samples by the conventional solid-state reaction technique. The samples were sintered at 1660–1840 °C for 8 h in the vacuum atmosphere ≤1 × 10−3 Pa. Nd:YAG ceramics sintered at 1780 °C had the pure cubic YAG phase composition and very dense microstructure with the relative density 99.85 %, so they had the pore-free microstructure and were highly transparent. Because of the pure phase composition and dense microstructure, Nd:YAG transparent ceramics had the outstanding microwave dielectric properties: ɛr = 10.66, Q × f = 2,30,400 GHz and τf = −27 ppm/°C. The high Q × f value and low dielectric constant ɛr suggested that Nd:YAG transparent ceramics were kind of promising dielectric substrate materials in microwave and millimeter wave electronic devices.