Magnetostructural phase transition in TbCo2-xFex: a neutron diffraction study

We have investigated the magnetostructural transition in TbCo2-xFex (x = 0 and 0.1) by variable temperature neutron powder diffraction experiment. From the Rietveld analysis of the neutron diffraction patterns at various temperatures for the x = 0 and 0.1 samples, we find that on substituting Fe at the Co site in TbCo2, the growth of the cubic phase (at the expense of the rhombohedral phase) spreads over a wide temperature range, indicating that the transition is broadened upon Fe substitution. We also find that on substituting Fe, the structural transition temperature shifts to higher temperature along with the magnetic transition temperature (from 231 K for TbCo2 to 303 K for TbCo1.9Fe0.1). (author)