Anomalies in the Elastic Constants and Thermal Expansion of Chromium Single Crystals

The temperature dependence of the elastic constants of two single crystals of chromium was investigated from 77 to 500°K. A detailed study was made of the anomalies at the Néel temperature, 310°K, and at the low-temperature transition at 120°K. The magnetic contribution to the elastic constants was found to be significant and to differ, in particular, between the two shear modes, $c_{44}$ and $\frac{1}{2}(c_{11}-c_{12})$. An anomaly in the coefficient of thermal expansion was observed at the Néel temperature.