Out-of-Plane Magnetic Anisotropy in Ordered Ensembles of Fe(y)N Nanocrystals Embedded in GaN

Phase-separated semiconductors containing magnetic nanostructures are relevant systems for the realization of high-density recording media. Here, the controlled strain engineering of Ga [Formula: see text] FeN layers with Fe [Formula: see text] N embedded nanocrystals (NCs) via Al [Formula: see text] Ga [Formula: see text] N buffers with different Al concentration [Formula: see text] % is presented. Through the addition of Al to the buffer, the formation of predominantly prolate-shaped [Formula: see text]-Fe [Formula: see text] N NCs takes place. Already at an Al concentration [Formula: see text] ≈ 5% the structural properties—phase, shape, orientation—as well as the spatial distribution of the embedded NCs are modified in comparison to those grown on a GaN buffer. Although the magnetic easy axis of the cubic [Formula: see text] ’-Ga [Formula: see text] Fe [Formula: see text] N nanocrystals in the layer on the [Formula: see text] buffer lies in-plane, the easy axis of the [Formula: see text]-Fe [Formula: see text] N NCs in all samples with Al [Formula: see text] Ga [Formula: see text] N buffers coincides with the [Formula: see text] growth direction, leading to a sizeable out-of-plane magnetic anisotropy and opening wide perspectives for perpendicular recording based on nitride-based magnetic nanocrystals.