Pressure-Induced Antiferromagnetism of Fe₂P

Abstract

The magnetization of Fe 2 P single crystal was measured as a function of magnetic field H , temperature T and hydrostatic pressure p , for 0≤ H ≤20 kOe, 4.2K≤ T ≤260 K and 0≤ p ≤14 kbar. It was found that the pressure-induced new magnetic phase below T =170 K and above p =5 kbar is the antiferromagnetic with one and unusual two steps metamagnetic behaviours. H - T magnetic phase diagrams were obtained at various pressures and they contains ferromagnetic, antiferromagnetic, intermediate and paramagnetic phases. In contrast with the drastic change in the Curie temperature with pressure, the magnetization at 4.2 K was pressure-insensitive. The pressure-induced magnetic transition and the antiferromagnetism of Fe 2 P are qualitatively discussed on the basis of the competition between the two different interactions and of the itinerant electron theory recently developed.