fig3

Figure 3. The full profile diffraction patterns of SnSb₂Te₄ at (A) 8.9, (B) 15.5, (C) 3.1 and (D) 44.7 GPa. The solid lines in red represent the fitting curves of the diffraction patterns of the involved structures via Le Bail refinements, and open circles represent the experimental data points. The solid lines in black at the bottom represent the residual deviations between the fitted and the observed intensities. The vertical bars indicate the theoretical peak positions of the involved structural phases. The diffraction patterns in (A) comprise a mixture of phases I and II. Those in (B) comprise a mixture of phases II and III. (E) The pressure dependence of the lattice parameters for phase I. The lattice parameters are indicated by squares, solid circles, and hollow circles, corresponding to the data reported by Sans et al.^[20] and those obtained experimentally and theoretically in the present study. The inset shows the pressure dependence of the axial ratio c/a.