Roger Ward

Abstract:

The magnetic ordering in HoxCe1-x alloys has been investigated by neutron diffraction and X-ray magnetic resonant scattering (XMRS). The DHCP alloys display a rich phase diagram, and highly unusual, diffuse neutron magnetic scattering is observed over the composition range 0.35≤x≤0.5. The diffuse intensity may be the magnetic response of the conduction band, and this interpretation is supported by the XMRS measurements, which show that there is hybridization of the Ce 4f electron with the conduction electrons.

Abstract:

Neutron diffraction studies of heavy rare-earth superlattices have revealed the stabilization of novel magnetic phases that are not present in bulk materials. The most striking result is the propagation of the magnetic ordering through nonmagnetic spacer materials. Here we describe some recent X-ray magnetic resonant scattering studies of light rare-earth superlattices, which illuminate the mechanism of interlayer coupling, and provide access to different areas of Physics, such as the interplay between superconductivity and magnetism. Magnetic X-ray diffraction is found to be particularly well suited to the study of the modulated magnetic structures in superlattices, and provides unique information on the conduction-electron spin-density wave responsible for the propagation of magnetic order.

Abstract:

A thin-film laminated structure comprised of Pd(5 nm)/Nb(5 nm)/Y(500 nm)/Nb(5 nm) on (Formula presented) was synthesized by molecular beam epitaxy to yield a crystalline Y layer with the c axis oriented perpendicular to the growth plane. Neutron diffraction and topographical measurements of the epitaxial (Formula presented) layer formed after deuteriding the Y metal layer were consistent with a twinlike structure possessing (Formula presented) and/or (Formula presented) symmetry. © 2000 The American Physical Society.