Interfacial nanostructure induced spin-reorientation transition in   Ni/Fe/Ni/W(110)
  We investigated the mechanism of the spin-reorientation transition (SRT) in the Ni/Fe/Ni/W(110) system using in situ low-energy electron microscopy, x-ray magnetic circular dichroism measurements, and first principles electronic structure calculations. We discovered that the growth of Fe on a flat Ni film on a W (110) crystal resulted in the formation of nanosized particles, instead of a uniform monolayer of Fe as commonly assumed. This interfacial nanostructure leads to a change of the system's dimensionality from two dimensional- to three dimensional-like, which simultaneously weakens the dipolar interaction and enhances the spin-orbit coupling in the system and drives the observed SRT. 
J.-S. Lee, J. T. Sadowski, H. Jang, J.-H. Park, J.-Y. Kim, J. Hu, R.   Wu, and C.-C. Kao
cond-mat.mtrl-sci