Hole contribution to the elastic constants of SnTe

Ultrasonic wave velocities have been measured in SnTe single crystals with hole concentrations of 1.0 and 4.5 × 1020/cm3. The shear elastic stiffness constant C44 is sensitive to the hole concentration but 12 (C11 − C12) is not, a result which is consistent with the valence band pockets being sited at the L points. The non-ellipsoidal, non-parabolic multivalley band model has been used to calculate the hole contribution to the elastic constants. The calculated difference between the shear constant C44 (2.78 × 1010 dyne cm-2) for the two crystals is in agreement with that measured experimentally (2.67 × 1010 dyne cm-2). The shear deformation potential constant Eu for the SnTe valence band is 7.8 eV at 293°K.