Brillouin scattering in single crystals of β-nitrogen: Determination of the elastic constants in the triple point

The technique of high resolution Brillouin spectroscopy has been used to determine the adiabatic elastic constants of oriented single crystals of β-nitrogen at temperatures near the triple point (63.15 K). The values obtained were c11=1.8(25), c12=1.1(31), c44=0.32(0), c33=1.9(76), and c13=0.9(80) (in units of 1010 dyn cm−2) with an estimated uncertainty of ±2%. These results indicate that crystals of β-nitrogen are close to being elastically isotropic.