Magnetic structure in iron borates RFe3(BO3)4(R = Y,Ho): a neutron diffraction and magnetization study

Neutron diffraction, susceptibility and magnetization measurements were performed on iron borates RFe 3 (BO 3 ) 4 (R = Y, Ho) to investigate the low temperature magnetic structures and to clarify the role of the rare earth in the formation of the long-range magnetic order. Both compounds see an identical magnetic propagation vector τ = [0,0,1/2] within the P 3 1 21 crystallographic space group appear at Néel temperatures of T N = 37 K for the Y and T N = 38 K for the Ho compound. The strong polarization effect of the Fe sublattice on the Ho 3+ ions leads to the simultaneous ordering of both sublattices while the competition between their anisotropies governs the spin-reorientation process at T SR = 5 K. The results obtained are discussed in the framework of the determined structural details and the specific rare-earth ions present including information on compounds investigated earlier.