EVALUATION OF a.c. CONDUCTIVITY BEHAVIOR OF SiC FILLED MgO

Composite of MgO having different amounts of SiC particles has been prepared using powder technology technique. Temperature dependence of dielectric constant, dielectric loss, and volume resistivity was measured in the frequency range 40 Hz-5MHz and sintering temperatures 800,1000, and 1450 °C for 2,4,6,8 wt % SiC. It was observed that the increase in temperature leads to increasing in dielectric constant and decreasing in dielectric loss and volume resistivity. Addition of 8wt % of SiC produces an increased in dielectric constant, dielectric loss, and volume resistivity respectively comparing to the same sintering temperature and frequency that uses with less addition. The addition of SiC particles enhanced the value of dielectric constant of MgO/SiC composite and the enhancement was found to be a function of the concentration of SiC powder