Magnetic structure and magneto-volume anomalies in Er2Fe17 compound

Abstract

Neutron powder diffraction shows that the intermetallic Er2Fe17 compound with hexagonal crystal structure has a ferrimagnetic ground state (TC = 303 K). At T = 5 K the magnetic moments of Fe sublattice (μ ~ 2 μB) are therefore antiparalell to those of the Er one (μ ~ 9 μB), all of them lying on the basal plane. This compound exhibits strong magnetovolume effects up to temperatures in the vicinity of TC. Neutron thermo-diffraction experiments also show an anomalous temperature dependence of the cell volume, including a negative thermal expansion coefficient below 300 K. In addition, a positive spontaneous volume magnetostriction is observed up to T ~ 400 K, with a maximum (ωS ~ 0.02) located at T = 5 K.