Coordinating microwave dielectric and optical properties of transparent yttrium aluminum garnet ceramics by regulating spark plasma sintering parameters

Abstract

Current studies on yttrium aluminum garnet (Y3Al5O12, YAG) ceramic are mainly focused on its optical properties and hardly pay attention to its microwave dielectric properties. This work systematically studies the coordination of the microwave dielectric and optical properties of YAG ceramics by exploring the effects of heating rate, sintering temperature, and holding time on the microstructure, dielectric properties, and transmittance of YAG ceramics fabricated by spark plasma sintering. Results show that the sintering parameters affect the microstructure of YAG ceramics, thereby affecting their microwave dielectric properties and transmittance. However, the change trends of the microwave dielectric and optical properties with the changes in sintering parameters are not exactly the same. The microwave dielectric and optical properties of YAG ceramics can be effectively coordinated by regulating the sintering parameters. The tunable ranges of the satisfactory transmittance, Q × f, εr, and τf are 80.1%–82.0% at 1064 nm wavelengths, 88,587–105,934 GHz, 10.5–10.7, and −53.5–−54.6 ppm/°C, respectively.