Dielectric properties of epoxy/Al2O3 nanocomposites depending on frequency and temperature

In this study, we investigated dielectric properties that fabricated samples with Al2O3 nanoparticles that have excellent thermal stability. And we examined equivalent circuit of nanocomposites through frequency response and could understand structure in Epoxy/Al2O3 from equivalent circuit. Also transition temperature was occurred by increasing temperature, investigated that changing permittivity due to phase transition. Al2O3 have excellent thermal stability, proper permittivity and Epoxy/Al2O3 nanocomposites expressed an equivalent circuit as two series and parallels RC circuit in this study. And we analyzed an equivalent circuit include bulk, grain, grain boundary in Epoxy/Al2O3 nanocomposites. As a results of this study, permittivity decreased by increasing frequency, and relaxation phenomenon occurred. Also we understand that ε″ shows transition temperature about 110 °C