Abstract The thermal expansion coefficients, αi, of deuterated (90%) TGS crystals has been measured for the three main directions a, b, c* in the temperature range 300-400 °K. The anomalous part of the thermal expansion has been examined by fitting the data to logarithmic corrections with powers 1 and 1/3. The electrostriction coefficients Qi22 for DTGS have been calculated from dilatation measurements. The results obtained have been compared with those for TGS crystals.
