The elastic constants of single crystal β-Si3N4

Abstract

Using Brillouin scattering, we have determined the complete set of elastic constants of the technologically important β-Si3N4. Availability of single crystals has allowed us to measure all five independent cij, which (in units of GPa) are: c11=433(3), c33=574(3), c13=127(5), c44=108(2), c66=119(4), and c12=c11−2c66=195(8), giving a bulk modulus of 259. Our values are compared with existing calculations and cij determined from nano-indentation results combined with empirical relations and trends in related materials.