Dielectric Behaviour of AgNa (NO2)2Powders

Abstract

Dielectric constant of compressed AgNa(NO 2 ) 2 powders of various particle size has been measured at 1 kHz over a wide range of temperature. The dielectric constant decrease with the decrease in particle size. Dielectric anomaly at the ferroelectric transition has completely disappeared for powders of less than 100 µm particle size. The measured values of the dielectric constant even for the biggest particle size are lower than the theoretically expected value for a polycrystalline sample. A reasonably good explanation of such a behaviour has been given by postulating the formation of defective surface layer of low dielectric constant.