Hydrogen and the magnetic interlayer exchange coupling: Variable magnetic interlayer correlation in Ho/Y(00.1) superlattices

摘要

We report on the influence of deuterium on the magnetic properties and the interlayer exchange coupling in superlattices incorporating the magnetic rare earth holmium. By neutron reflectivity and diffraction we investigate the effect of deuterium on the properties Ho/Y(00.1) superlattices. We find that deuterium up-take occurs with strong preference in the yttrium layers. Via magnetic neutron scattering we establish that for this model rare earth system the interlayer coupling can be effectively suppressed through the introduction of deuterium. The gradual loss of the long-range coherence of the magnetic order mediated by the nonmagnetic yttrium layers is discussed in terms of partial interlayer correlation. In a second Ho/Y(00.1) superlattice, composed of ultrathin holmium films, deuterium is an effective agent to vary the total exchange energy of the system and finite size effects on the ordering temperature T_C are observed.