Magnetic and magnetoelastic properties of epitaxial SmFe2 thin film

We report on magnetic and magnetoelastic measurements for a 5000 A (110) SmFe2 thin film, which was successfully analyzed by means of a point charge model for describing the effect of the epitaxial growth in this kind of system. Some of the main conclusions of the Moessbauer and magnetoelastic results and the new magnetization results up to 5 T allow us to get a full description of the crystal electric field, exchange, and magnetoelastic behavior in this compound. So, new single-ion parameters are obtained for the crystal field interaction of samarium ions, A4(r4) = +755 K/ion and A6(r6) = -180 K/ion, and new single-ion magnetoelastic coupling Bγ,2≅-200 MPa and Bε,2≅800 MPa, which represent the tetragonal and the in-plane shear deformations, respectively. Moreover, the new thermal behavior of the samarium magnetic moment, the exchange coupling parameter, and the magnetocrystalline anisotropy of the iron sublattice are obtained too. From these, the softening of the spin reorientation transition with respect to the bulk case could be accounted for.