High-pressure angle-dispersive X-ray diffraction study of mechanically alloyed SnSe2

The effect of pressure on mechanically alloyed trigonal nanostructured SnSe2 (n-SnSe2) was studied by in situ angle-dispersive X-ray diffraction up to 25.8 GPa. The pressure dependence of lattice parameters and unit cell volume was investigated. By fitting the lattice parameters and unit cell volume to a third-order Birch–Murnaghan equation of state for several values of the applied pressure, the bulk modulus B0, its first derivative B′, and the linear moduli along the a- and c-axes were determined. The effect of pressure on the z coordinate of site 2d occupied by Se atoms was investigated using pair distribution function analysis. The results were compared with experimental and theoretical studies of SnS2 and SnSe2 reported in the literature.