Magnetic properties of Ho2Fe17-xMnx - influence of Mn substitution.

Abstract

The structural and magnetic properties of Ho2Fe17−xMnx (x=0−5) have been investigated by x-ray diffraction, Mössbauer spectroscopy and DC magnetization measurements (0-5 T) over the temperature range 4.5–350 K. Similar to other ferrimagnetic R2Fe17−xMnx systems, the unit cell volume generally increases with Mn content other than for low Mn values where a slight maximum is detected around x ~ 0.5. The nature of the magnetic phase transitions around TC is shown by Arrot plot analysis to be second order for all samples. The Curie temperature remains essentially unchanged for Mn contents up to x=1.0 (TC = 336 K for x=0.0, TC = 338 K for x=1.0) before decreasing steadily with further increase in Mn content (TC = 209 K for x=5). The 57Fe hyperfine interaction parameters have been determined from variable temperature Mössbauer spectra.