THE STRUCTURAL AND MAGNETIC-PROPERTIES OF HOLMIUM SCANDIUM SUPERLATTICES/

The properties of Ho/Sc superlattices grown by molecular beam epitaxy (MBE) have been investigated using X-ray and neutron diffraction techn iques. Structural studies reveal the novel existence of more than one a lattice parameter. Examining the magnetic properties, it is found th at the Ho 4f moments form a basal-plane helix at all temperatures, wit h the exception of one sample for which there is a low-temperature tra nsition to a ferromagnetic phase. In the helical phase, some samples e xhibit a short-range coherence of an overall antiferromagnetic couplin g between adjacent Ho blocks.