Modification of spin-ice physics in Ho 2 Ti 2 O 7 thin films

摘要: We present an extensive study on the effect of substrate orientation, strain, stoichiometry, and defects spin-ice physics in ${\mathrm{Ho}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$ thin films grown onto yttria-stabilized-zirconia substrates. find that growth different orientations produces strain states films. All exhibit similar $c$-axis lattice parameters for their relaxed portions, which are consistently larger than bulk value 10.1 \AA{}. Transmission electron microscopy reveals antisite disorder to be films, but evidence stuffing is not observed. The amount depends with (110) film showing least. Magnetization measurements at 1.8 K show expected magnetic anisotropy saturation magnetization values associated a spin ice all orientations; shape apparent when comparing in- out-of-plane directions. Significantly, only (110)-oriented display hallmark plateau state magnetization, albeit less well defined compared observed single crystal. Neutron-scattering maps more disordered (111)-oriented $Q$ = 0 phase previously materials, $X$ giving remains elusive. conclude modified by leading reduction temperature correlations drive system into state.