High-Pressure and High-Temperature in situ X−Ray Diffraction Study of FeP₂ up to 70 GPa

The high-pressure and high-temperature structural behavior of FeP₂ is investigated by means of synchrotron x−ray powder diffraction combined with a laser heating technique up to 70 GPa and at least 1800 K. No phase transition of FeP₂ occurs up to 68 GPa at room temperature. While a new phase of FeP₂ assigned to the CuAl₂−type structure (I4/mcm, Z=4) is observed at 70 GPa after laser-heating. This new phase presents a quenchable property on decompression to ambient conditions. Our results update previous experimental data and are consistent with theoretical studies.