Microwave dielectric properties of pure YAG transparent ceramics

The microwave dielectric properties of YAG transparent ceramics were investigated. The samples were prepared by the conventional solid-state reaction technique with the high purity raw materials. And they were sintered at 1600–1800°C for 4–12h in the vacuum atmosphere ≤1×10−3Pa. YAG transparent ceramics sintered at 1750°C for 8h had the pure cubic YAG phase and pore-free microstructure with relative density 99.8%, and they were highly transparent. YAG transparent ceramics had the outstanding microwave dielectric properties: εr=10.8, Q×f=213,400GHz and τf=−30ppm/°C. The high Q×f value and low εr suggested that YAG transparent ceramics would be kind of promising microwave dielectric substrate materials.