Low dielectric loss and non-Debye relaxation of gamma-Y2Si2O7 ceramic at elevated temperature in X-band

Bulk single-phase gamma-Y2Si2O7 ceramic has been synthesized from a mixture of Y2O3 powder and SiO2 nanopowder at 1400 degrees C. The dielectric properties are reported at the temperature ranging from room temperature to 1400 degrees C in X-band. The results show that gamma-Y2Si2O7 exhibits low dielectric loss and non-Debye relaxation behavior different from that of SiO2. The peculiar relaxation peak is attributed to the structural relaxation polarization caused by thermal-excitation structural defects, which implies that no ionic conductance exists in this material. Such low dielectric loss will draw much attention for potential dielectric applications at high temperature.