Effect of severe plastic deformation on the properties of the Pt3Fe antiferromagnet

Abstract

The effect of atomic disordering on the magnetic, electrical, and optical properties of the Pt74.1Fe25.9alloy close in composition to the stoichiometric Pt3Fe alloy has been studied. It has been shown that, as a result of severe plastic torsional deformation under high pressure, the alloy transforms from the antiferromagnetic state (TN=164 K) into the ferromagnetic state (TC≈400 K). In this case, the residual electrical resistivity increases by a factor of more than two and the thermopower changes its sign from positive to negative. The results of the studies of the optical conductivity agree with the previously calculated electronic spectra of the atomically ordered and disordered Pt3Fe alloys in the range of interband transitions and with the obtained data on the electrical properties in the infrared range.