Magnetic properties of step-decorated Fe nanostripes and dots grown on Mo(110)

Arrays of epitaxial Fe(110) nanostripes 1-5 nm thick and similar to100 nm wide are fabricated under UHV by pulsed laser deposition on a stepped Mo(110) surface. This step decoration process results from surface diffusion limitations at 500 K, or alternatively from the occurrence of a metastable 6-atomic-layer thickness upon annealing a continuous film grown at room temperature. The stripe orientation and spacing are uniform over the whole sample as controlled by the 0.05degrees miscut of the substrate. Room temperature magnetic properties are investigated by vibrating sample magnetometry. In the case of steps parallel to Fe[001], all sources of anisotropy contribute to align the magnetization parallel to the step direction, yielding a rather square hysteresis loop with a coercive field of 70mT. Average single particle behavior is extracted by differentiating the reversible and the irreversible magnetic contributions deduced from a series of minor hysteresis loops. A model with no interaction between the particles well reproduces the experimental results. (C) 2002 Published by Elsevier Science B.V.