Mössbauer investigation of the peculiar magnetism of Tb(Mn 1−xFe x) 2 at small substitution of Fe for Mn

Abstract

Mössbauer experiments have been performed on the Tb(Mn 0.96Fe 0.04) 2 intermetallic compound from liquid nitrogen temperature down to liquid helium temperature. Above 34 K, the obtained spectra are interpreted in a two sites model with populations in the ratio 3:1. Below 34 K, each site splits into two equally populated subsites differing from each other by the quadrupolar splitting and isomer shift. At this temperature, one observes also a rotation of the hyperfine field of the site of population 1. These data are consistent with an earlier proposal of a collinear magnetic structure at high temperature where only one Mn atom over four is magnetic, with a reorientation of the corresponding moment below 34 K as has been shown up by neutron scattering.