ESR Investigation of TGS Doped with Cr3+ Ions

We observed the ESR signal of Cr 3+ ions in triglycine-sulphate. It is found that a pair of lines gradually approach to each other with increasing temperature in the ferroelectric phase and converge at the Curie temperature. The results are interpreted by using the concept of motional narrowing on the basis of the model of order-disorder type. The linewidth for the applied magnetic field nearly parallel to the principal axis z shows an anomalous increase near the Curie temperature. The critical exponent of the linewidth in the ferroelectric region is determined to be 0.5 in the vicinity of the Curie temperature and to be 2.0 far from the Curie temperature.