Polarization Relaxation in Triglycine Sulfate above the Curie Temperature

Measurements of the complex dielectric constant for normal and deuterated triglycine sulfate are reported. These measurements cover a range of 20^∘{}C above the Curie temperature and frequencies up to 7.7×{}10¹⁰ cps. A frequency- and temperature-dependent relaxation of the dielectric constant was observed which first sets in around 5×{}10⁷ cps. It was found that all the observations of ε* could be expressed as ε*=CT-Tc[f(ντ₀)+ig(ντ₀)], where C and Tc are the Curie constant and temperature; and τ₀ is inversely proportional to (T-Tc). Expressions for f(ντ₀) and g(ντ₀) which give a good fit to the data were derived by assuming that each dipole has a Debye relaxation characteristic and that there is a Gaussian distribution of relaxation times, with τ₀ being the measure of the width of the distribution.