The four elastic constants of diamond

Abstract

The thermal scattering of light in diamond has been studied in great detail by R. S. Krishnan and by V. Chandrasekharan. These authors pointed out that the frequency shifts observed for the Brillouin components are not in good agreement with the values calculated using the elastic constants data of Bhagavantam and Bhimasenachar. The values of the elastic constants have since been determined by Prince and Wooster and recently much more accurately by McSkimin and Bond. McSkimin and Bond's values do not agree with those of Bhagavantam and Bhimasenachar and of Prince and Wooster, especially as regards C₁₂ and C₄₄. Using the values of McSkimin and Bond, the frequency shifts of the Brillouin components for the various orientations studied by Chandrasekharan with the bigger speetrograph were calculated, but the agreement with the experimental values was still unsatisfactory. We have therefore evaluated the elastic constants of diamond directly from the observed frequency shifts