Low dielectric loss and non-Debye relaxation of gamma- Y₂Si ₂ O₇ ceramic at elevated temperature in X -band

Bulk single-phase gamma- Y₂ Si₂ O₇ ceramic has been synthesized from a mixture of Y₂O₃ powder and SiO₂ nanopowder at 1400 °C. The dielectric properties are reported at the temperature ranging from room temperature to 1400 °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.