Purpose-led Publishing logo. Study of hyperfine-field distributions and the lattice dynamics of Fe50Ni30Cr20 alloy by using 57Fe Mössbauer spectroscopy

Abstract

This paper reports a 57Fe Mössbauer spectroscopic study of a polycrystalline sample of the substitutionally disordered, isostructural (fcc), ternary alloy Fe50Ni30Cr20 over the temperature range 10 to 295 K. The data have been analysed in terms of the magnetic phase transitions occurring in the alloy by examining the temperature dependence of the Mössbauer parameters. The Curie temperature has been determined by fitting the average hyperfine-field values obtained at different temperatures. In order to achieve a detailed understanding of the nature of the hyperfine-field distribution corresponding to the Mössbauer spectra of this alloy, the curves representing the probabilities of the hyperfine-field distributions versus the hyperfine field have been refitted by using two independent Gaussians. On the basis of these fits, the local magnetic ordering of this alloy at low temperature has been described. The data on the second-order Doppler shift have been analysed in order to obtain an estimate of the Debye temperature, ΘD, and a description of the lattice dynamics.