TriGlycine Sulphate The dielectric behavior of triglycine sulphate has been investigated near the phase-transition temperature for varying thicknesses of the crystal. Measurements have been carried out at a frequency of 1 kHz. The results indicate that the dielectric constant of triglycine sulphate does not go to infinity at the transition temperature. The deviation from the Curie-Weiss law near the transition temperature and the broadening of the peak with decreasing thickness of the crystal can be explained by assuming a surface layer of low dielectric constant, while internal bias can explain the shift in the transition temperature. Journal of Applied Physics is copyrighted by The American Institute of Physics.