Photoemission electron microscopy study of sub-200 nm self-assembled La0.7SrLa0.3MnO3 epitaxial islands.

The chemical composition and the magnetic structure of individual La0.7Sr0.3MnO3 (LSMO) ferromagnetic manganite epitaxial nanostructures less than 200 nm in width are explored using Photoemission Electron Microscopy (PEEM). X-ray absorption spectra (XAS) provide separate information on the surface and the bulk composition of the nanoislands and give evidence of Mn(2+) present on the surface of otherwise stoichiometric nanostructures. Ferromagnetic domains less than 70 nm are resolved using X-ray magnetic circular dichroism (XMCD), which allows for the detection of magnetic vortex states in both (001)LSMO square and (111)LSMO triangular manganite nanoislands. The evolution of single nanostructures under an in-plane magnetic field is seen to depend on the specific nanoisland size and geometry. In particular, PEEM XMCD imaging allows detecting opposite chiralities as well as a variety of magnetization behaviors for different nanoislands.

Orientational ordering of solution derived epitaxial Gd-doped ceria nanowires induced by nanoscratching.

When one-dimensional nanostructures are epitaxially grown on a substrate a key goal is to control the nanowire's position and orientation. Nanoscratching of single crystalline (001)- LaAlO(3) substrates is demonstrated to be extraordinarily effective in directing the self-assembly of Ce(0.9)Gd(0.1)O(2-y) epitaxial nanowires grown by chemical solution deposition. The local anisotropic elastic strain field imposed by the indentation lines is responsible for the breaking of the pre-existing orientation energy degeneracy and selects the nanowires' orientation parallel to the lines to an extent that can reach 100%.