Abstract
Strain-induced splittings of the infrared-active TO phonon in Ca, Sr, and Ba are calculated from a least-squares fit of photoelastic dispersion data by an undamped oscillator model. The strain-induced oscillator-strength anisotropy appears negligible; the Szigeti effective charge remains a scalar. The shear deformation potential for [100] strain is ∼170 in all the materials; for [111] strain it is -82 for Ca, -54 for Sr, and -50 for Ba.
- Received 21 January 1980
DOI:https://doi.org/10.1103/PhysRevLett.45.126
©1980 American Physical Society