Magnetic structure of magnetoelectric multiferroic HoFeWO6

• Published in: Journal of magnetism and magnetic materials Vol. 544; no. 1
• Main Authors: Dhital, C., Dally, R. L., Pham, D., Keen, T., Zhang, Q., Siwakoti, P., Nepal, R., Jin, R., Rai, R.
• Format: Journal Article
• Language: English
• Published: United States Elsevier 30-10-2021
• Subjects: magnetic structure; magnetism; magnetoelectric coupling; MATERIALS SCIENCE; neutron diffraction
• ISSN: 0304-8853

The polar magnetic oxide, HoFeWO6, is synthesized, and its crystal structure, magnetic structure, and thermodynamic properties are investigated. HoFeWO6 forms the polar crystal structure (space group Pna21 (#33)) due to the cation ordering of W6+ and Fe3+. An antiferromagnetic transition at TN = 17 K is accompanied by a significant change in magnetic entropy with a value of ≈ 5 J kg-1 K-1 in a 70 kOe applied field. Temperature dependent neutron diffraction and magnetization data indicate that the Fe sublattice orders in a strongly non-collinear and non-coplanar arrangement below TN. The Fe ordering initially leads to induced ordering of the Ho spins such that the Ho spins also show behavior of long-range ordering that is evident from the neutron diffraction measurements. Below T ≈ 4 K, the Ho spins order independently and pull the Fe spins toward the direction of Ho spins. A comparison with the magnetic structures and corresponding ferroelectric properties of other members of RMWO6 (R = Y, Sm-Tm, M = Cr, Fe, V) family indicate that the spontaneous polarization is due to the magnetic structure specific to the Fe sublattice through magnetoelectric coupling whereas the polarization is independent of the Ho sublattice.