Epitaxial Sm thin films and Sm/Y superlattices have been grown with a high
single-crystal quality. The complex nine hexagonal close-packed planes stac
king sequence has been successfully obtained in a 5000-Angstrom-thick film,
whose magnetic behavior presents a long-range antiferromagnetic order of t
he hexagonal sites below 100 K, as in the bulk element. However, from neutr
on scattering, the relative magnetic and nuclear contributions indicate a s
ignificant enhancement of the magnetic moment compared to the bulk value. F
or the superlattice, the neutron-scattering results show neither long-range
structural coherence of the stacking sequence along the c direction nor a
coherent magnetic ordering at low temperatures. [S0163-1829(99)15035-5].