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.
@article{arxiv.1104.5266,
title = {Interfacial nanostructure induced spin-reorientation transition in Ni/Fe/Ni/W(110)},
author = {J. -S. Lee and J. T. Sadowski and H. Jang and J. -H. Park and J. -Y. Kim and J. Hu and R. Wu and C. -C. Kao},
journal= {arXiv preprint arXiv:1104.5266},
year = {2011}
}