Lattice distortion and magnetic properties of nanometer size Fe(110) islands

Epitaxial Fe(1 1 0) islands of nanometric dimensions have been obtained on c-sapphire by triode sputtering. By ex situ X-ray diffraction (XRD) measure ments we observe a strong dependence of the perpendicular lattice parameter as a function of the vertical island size and the deposition geometry. Dep osition with the substrate facing the Fe target gives rise to almost relaxe d islands. However, deposition with the substrate facing opposite to the Fe target yields to highly distorted islands (up to 5%) along the growth dire ction). XRD rocking scans show two components in k parallel: a narrow one, independent of the island dimension, that it is correlated to the Fe/sapphi re interface, and a broad one, related to its in-plane disorder, the width of which decreases when the island lateral dimension is increased. Correlat ion of the structural changes with the magnetization reversal processes and magneto-optical properties are studied. (C) 2001 Elsevier Science B.V. All rights reserved.