The effect of surface layers on the dielectric behaviour of triglycine sulphate

Abstract

The dielectric constant of triglycine sulphate in the form of compressed powders of varying particle sizes ranging from 55 to 500 μm has been measured at 100 KHz from 0 to 90 °C. Dielectric anomalies indicating the existence of ferro-electricity were observed for particle sizes up to 55 μm. The dielectric constant decreases with decreasing particle size and is much lower than that expected theoretically. These results have been qualitatively explained by postulating the formation of a defective surface layer of low dielectric constant.