Temperature Variation of the Elastic Constants of Cubic Elements. I. Copper

摘要: The ultrasonic pulse technique has been used in conjunction with a specially devised cryogenic to measure the velocities of 10-Mc/sec acoustic waves copper single crystals range from 4.2\ifmmode^\circ\else\textdegree\fi{}K 300\ifmmode^\circ\else\textdegree\fi{}K. values and temperature variations elastic constants have determined. room were found agree well those other experimental works. Fuchs' theoretical ${c}_{44}$ at 0\ifmmode^\circ\else\textdegree\fi{}K is 10 percent larger than our observed value but his ${c}_{11}$, ${c}_{12}$, $K$ (${c}_{11}\ensuremath{-}{c}_{12}$) observations. isotropy, $\frac{({c}_{11}\ensuremath{-}{c}_{12})}{2{c}_{44}}$, was remain practically constant 180\ifmmode^\circ\else\textdegree\fi{}K, then diminish gradually higher temperatures. Some general features are discussed.