57 Fe Mössbauer and Magnetic Studies of Nd 3 Fe 24.5 Cr 4.5

The structural and magnetic properties of the rare earth transition metal compound Nd 3 Fe 24.5 Cr 4.5 have been investigated by variable temperature high resolution x-ray diffraction together with DC magnetization and 57 Fe Mössbauer effect measurements. The magnetic ordering temperature has been found to be T C = 423(5) K with spin reorientation detected below room temperature around T sr = 158(5) K. Rietveld refinements indicate that Nd 3 Fe 24.5 Cr 4.5 crystallizes in the Nd 3 (Fe,Ti) 29 -type structure with the A2/m space group and a substantial magneto-volume effect is detected around T C . The Mössbauer spectra can be fitted well using five sub-spectra. The temperature dependence of the average hyperfine field has been analysed in terms of different power laws of the reduced temperature. The Debye temperature of Nd 3 Fe 24.5 Cr 4.5 has been determined as 𝜃 D = 400(± 30) K from a fit to the variable temperature isomer shift IS(T).