An investigation was made of the anisotropic properties of Fe films obtaine
d by molecular-beam epitaxy on GaAs(100) substrates. It is shown that at th
icknesses t = 40-50 Angstrom the Fe films begin to exhibit cubic magnetic a
nisotropy. At thicknesses t > 100 Angstrom the first constant of cubic anis
otropy K-1 has values similar to those for "bulk'' Fe single crystals. Film
s of intermediate thickness 50 < t < 100 Angstrom possess both isotropic an
d anisotropic phases. (C) 1999 American Institute of Physics. [S1063-7850(9
9)03201-2].