Abstract
Thin films of DyFe2 and ErFe2 have been epitaxially grown along the [110]
direction. At 4.2 K, the easy magnetization axis in the films, determined
by Mössbauer spectroscopy, is the same as in bulk compounds (i.e.
⟨100⟩
for DyFe2 and ⟨111⟩ for ErFe2). At 300 K, the magnetic
moments, which remain in the same direction as at 4.2 K in bulk compounds, rotate
towards ⟨110⟩ directions in thin films: they are close to the in-plane
[1
0] direction in
DyFe2 films, and close to the perpendicular-to-the-plane [110] direction
in ErFe2 films. These modifications of the magnetic anisotropy are related
to the epitaxial strains, and to the sign and the relative importance of
the anisotropy and magnetoelastic constants of the compound.