High-pressure phase transition in 57 Fe 0.03 Cr 0.97 Sb 2 : A Mössbauer and resistivity study up to 8 GPa

We report Mössbauer and resistivity measurements at 2.3 and 5.6 GPa and at room temperature for the 57 Fe 0.03 Cr 0.97 Sb 2 system using a diamond anvil cell. The observed isomer shift and quadrupole splitting in Mössbauer data can be interpreted in terms of a first-order structural phase transition from marcasite-type orthorhombic to pyrite-type cubic at about 6 GPa. A transformation from the high-spin to the low-spin state of Fe 2+ is also observed at this pressure. Electrical resistivity measurements up to 8 GPa on the system confirmed a first-order pressure-induced structural transition.