Equation of state of silicon nitride carbodiimide Si2CN4

The lattice parameters of silicon nitride carbodiimide Si2CN4 have been measured up to 8 GPa at room temperature using energy-dispersive X-ray powder diffraction with synchrotron radiation. A fit of the experimental p–V data to the Birch–Murnaghan equation of state yields the values of the bulk modulus of 8.8(2) GPa and its first pressure derivative of 3.4(1). The compression is found to be anisotropic, with the b-axis being significantly more compressible than the a-and c-axes.