Enhanced microwave dielectric properties of Al2O3 ceramics via a cold sintering assisted two-step sintering route

The effects of cold sintering assisted two-step sintering on the structural evolution and microwave dielectric properties of Al2O3 ceramics are systematically investigated in this work. XRD analysis reveals that the crystal structure remains stable throughout the cold sintering and following high-temperature sintering processes. Rietveld refinement confirms the trigonal Al2O3 configuration and the absence of impurities. Increasing cold sintering pressure results in improved relative density, reaching over 94