Study of Spontaneous Polarisation and Pyroelectric Modulus for the Triglycine Sulphate Crystals Doped by Chromium Ions

The temperature dependencies of a spontaneous polarisation, P$\text{}_{s}$, and pyroelectric modulus, γ, at different electric field intensities were investigated for the triglycine sulphate crystals doped with the Cr$\text{}^{3+}$ chromium ions. On the base of thermodynamic theory the temperature dependencies of P$\text{}_{s}$ and γ at different electric field intensities were estimated. The coefficients of the expansion of the thermodynamic potential were determined. The experimental results were compared with those obtained according to the thermodynamic theory.