Studies of Permittivity in the Triglicinium Sulphate Crystals Doped with Chromium Ions as a Function of Temperature and Electric Field

Permittivity in the triglicinium sulphate crystals doped with chromium ions Cr$\text{}^{3+}$ as a function of temperature and of intensity of electric field polarising the crystal was investigated. On the base of thermodynamical theory, the relationship among permittivity, temperature and electric field intensity was calculated. Coefficients of the expansion of the thermodynamic potential were determined. Experimental results were compared with those resulting from the thermodynamical theory.