Crossover from spin-flop coupling to collinear spin alignment in antiferromagnetic/ferromagnetic nanostructures

Nano Lett. 2012 May 9;12(5):2386-90. doi: 10.1021/nl300361e. Epub 2012 Apr 6.

Abstract

The technologically important exchange coupling in antiferromagnetic/ferromagnetic bilayers is investigated for embedded nanostructures defined in a LaFeO(3)/La(0.7)Sr(0.3)MnO(3) bilayer. Exploiting the element specificity of soft X-ray spectromicroscopy, we selectively probe the magnetic order in the two layers. A transition from perpendicular to parallel spin alignment is observed for these nanostructures, dependent on size and crystalline orientation. The results show that shape-induced anisotropy in the antiferromagnet can override the interface exchange coupling in spin-flop coupled nanostructures.