Homogeneity of triglycine sulphate crystals

Abstract

Powder suspensions in silicone oil have been used for decorating slices of TGS grown from aqueous solutions by conventional means, and by a spinning disc technique. The method provides a quick means of assessment of crystal quality and uniformity and has helped in the interpretation of some of the phenomena observed in electrical measurements on both undoped and doped TGS crystals. Sections of crystals grown with alanine as dopant — which gives the crystals an internal polarization bias — show a markedly non-uniform decoration pattern, indicative of a variation of polarization in different growth sectors. Much improved uniformity is demonstrated in crystals grown on a single surface under controlled conditions of solution flow.