The elastic constants for single-crystal lead and indium from room temperature to the melting point

The adiabatic elastic stiffness constants of indium and lead were measured from room temperature to their respective melting points using the ultrasonic pulse-echo method. The average temperature derivatives at constant pressure, $\text{dC}{}_{\mathrm{ij}}\text{dT}\text{= C'}{}_{\mathrm{ij}}$, for the indium constants are:

$\text{C'}{}_{11}\text{= ?0.032 C'}{}_{12}\text{= ?0.0055 C'}{}_{13}\text{= ?0.011 C'}{}_{33}\text{= ?0.032 C'}{}_{44}\text{= ?0.0059 C'}{}_{66}\text{= ?0.022}$

in units of 10¹⁰dyne cm^?2deg^?1, and are referred to axes coincident with those of the face-centered tetragonal unit cell. The average temperature derivatives at constant pressure for the lead elastic constants are, in the same units,

$\text{C'}{}_{11}\text{= ?0.0264 C'}{}_{12}\text{= ?0.0156 C'}{}_{44}\text{= ?0.0155.}$

The elastic anisotropies of both lead and indium increase markedly with increasing temperature.