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

摘要

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 Ti_(0.5-0.8)Fe_(1.5-1.2)P (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 Ti_(0.85-1.25)Fe_(1.15-0.75)P 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 Ti5P_(3.16), Ti3P and TiP phases, and Fe for Ti in the case of Fe3P, Fe2P binary compounds.