The Ti-Fe-P system: phase equilibria and crystal structure of phases

Phase equilibria was investigated in the Ti-Fe-P system at T = 1070 K in the region 0-67 at.% of P, employing X-ray powder diffraction. The two ternary compounds, namely Ti0.5-0.8Fe1.5-1.2P (Co2Si-type; space group Pnma; a = 0.5964(2)-0.6011(3), b = 0.3575(3)-0.3600(1), c = 0.6828(2)-0.6882(2) nm) and Ti0.85-1.25Fe1.15-0.75P (ZrNiAl-type; space group P-62m; a = 0.6071(4)-0.6117(1), c = 0.3510(9)-0.3506(1) nm) exist in the Ti-Fe-P system at this temperature. The crystal structure of the Ti0.85-1.25Fe1.15-0.75P compound was additionally determined by X-ray single crystal diffraction on the phase with stoichiometric composition. The substitutions of Ti by Fe were observed for Ti5P3.16, Ti3P and TiP phases, and Fe for Ti in the case of Fe3P, Fe2P binary compounds.