Brillouin scattering in single crystals of β-carbon monoxide: Determination of the elastic constants at the triple point

Abstract
The technique of high resolution Brillouin spectroscopy has been used to determine the adiabatic elastic constants of oriented single crystals of β‐carbon monoxide at temperatures near the triple point. The values obtained at 67.7 K were c11=1.9(01), c12=1.1(46), c13=0.9(51), c33=2.0(95) and c44=0.35(5) (in units of 109 Nm−2) with an estimated uncertainty of ±2%. The similarities to β‐nitrogen results are striking; nevertheless, significant differences are noted.