Dielectric Behavior of Hot‐Pressed AlN Ceramic: Effect of CaO Additive

Abstract

Temperature and frequency dependence of dielectric constant and dissipation factor has been studied in hot‐pressed samples of , with and without additive of (0.5–7.0 mole percent). It is observed that, in all the samples, the dielectric constant and dissipation factor increase quite appreciably at higher temperatures (>450 K), the increase being more at lower frequencies. At a particular temperature and frequency, dielectric constant and dissipation factors increase after putting 0.5 mole percent in pure . However, at higher concentrations (>3 mole percent), these parameters decrease. The results have been explained in terms of space charge polarization.