Magnetic order in an MnF2 epitaxial layer with the orthorhombic structure

The magnetic structure of MnF₂ is determined by the neutron diffraction method in the metastable orthorhombic phase grown in the form of thin (~1 μm) film on a CaF₂ buffer layer by the molecular beam epitaxy method. The magnetic moments of Mn⁺⁺ form a simple two-sublattice antiferromagnetic structure and are directed along the c crystallographic axis parallel to the film plane. Using the temperature dependence of magnetic reflections, a Néel temperature of 67.19(7) K and a critical index of 0.50(2), which corresponds to the mean field approximation, are determined.