Pronounced Change in the Low-Temperature Heat Capacity ofV3Si with Stress

A pronounced decrease of the heat capacity of ${\mathrm{V}}_{3}$Si in the stressed state has been observed at temperatures below ${T}_{c}$. In addition, a large increase of heat capacity in the stressed state is observed above about 25\ifmmode^\circ\else\textdegree\fi{}K. The effect does not appear to be directly related to the structural transformation per se since it was observed both in samples that transform and in samples that do not. The observations are consistent with a decrease in ${T}_{c}$ of about one degree in the most extensively stressed regions of the sample. So far as is known, these are the first observations of such a pronounced effect of stress on heat capacity (e.g., as much as a 20% decrease in the entropy of ${\mathrm{V}}_{3}$Si at 17\ifmmode^\circ\else\textdegree\fi{}K). Although our present understanding of the observations is incomplete, a large decrease in the density of states at the Fermi surface with stress, as proposed by Weger, appears to be involved.