Magnetic interactions in HoCr 1-x Fe x O 3 (x = 0, 0.2) investigated by neutron powder diffraction

Abstract The temperature dependent magnetism of Fe-doped rare earth orthochromite HoCr 1-x Fe x O 3 (x = 0, 0.2) was investigated by neutron powder diffraction. It is found that the magnetism of Cr(Fe) 3+ can be well understood within mean field theory, while the ordering of Ho 3+ was induced by the Cr(Fe) 3+ sublattice and can be satisfyingly described by an effective S = 1/2 model. The absences of both the most common G x F z configuration of Cr 3+ and the ordering of Ho 3+ caused by Ho-Ho interaction evidence a strong Ho 3+ -Cr 3+ interaction which dominates this system. On the other hand, a remarkable magnetoelastic strain was observed accompanying the Cr(Fe) 3+ ordering. An analysis based on the equation of state with a Gruneisen approximation was performed and revealed magnetic origin of this strain.