Amorphous metals have unusual magnetic properties that arise due to the disordered atomic arrangement. We show that Co x(Al70Zr30)100− x (65 < x < 92 at. %) amorphous alloys have a distribution in the local magnetic coupling and ordering temperature, which can be explained by nanoscale composition variations. We use competing anisotropies induced by the substrate and an applied field during growth to probe the Co concentration distribution. Only regions with high enough Co concentration develop a magnetic anisotropy along the magnetic field during growth, whereas regions of low Co concentration have an anisotropy dictated by the substrate. A Gaussian distribution in the Co concentration of width 5.1 at. % is obtained from the variation in anisotropy. The results demonstrate the importance of composition variations for emergent magnetic properties and have far reaching implications for the properties of disordered materials in general.

We report on the transport properties of epitaxial vanadium sesquioxide (V2O3) thin films with thicknesses in the range of 1 to 120 nm. Films with the thickness down to nanometer values reveal clear resistivity curves with temperature illustrating that even at these thicknesses, the films are above the percolation threshold and continuous over large distances. The results reveal that with the reducing thickness, the resistivity of the films increases sharply for thicknesses below 4 nm and the metal-insulator transition (MIT) is quenched. We attribute this increase to a strained interface layer of thickness ∼4 nm with in-plane lattice parameters corresponding to the Al2O3 substrate. The interface layer displays a suppressed MIT shifted to higher temperatures and has a room temperature resistivity 6 orders of magnitude higher than the thicker V2O3 films.