Formation of an anisotropy lattice in Co/Pt multilayers by direct laser interference patterning

We report on the use of direct laser interference patterning to form an anisotropy lattice in Co/Pt thin film multilayers. Co/Pt multilayers have been extensively studied and, for the compositions studied here, are characterized by strong perpendicular magnetic anisotropy in which the magnetic moment is perpendicular to the film plane. In direct laser interference patterning, two-to-four coherent laser beams from a pulsed Nd:YAG laser strike the sample surface simultaneously, and for sufficiently intense beams the sample properties are modified locally where interference maxima occur. Kerr rotation, magnetic force microscopy, and atomic force microscopy measurements after patterning by one pulse from the laser show that the films have a regular array of dots with in-plane magnetization in a background matrix of perpendicular magnetization. Such patterning holds promise for the study of model nanoscale magnetic systems. (C) 2006 American Institute of Physics.