Anisotropy measurements in mesoscopic magnets by magneto-optical torque

The development of a versatile tool to quantify magnetic anisotropies in continuous and patterned magnetic thin films is reported. The technique involves measuring the magnetooptic response to a rotating magnetic field. Similarly to mechanical torque techniques, a single measurement obtains both the anisotropy constants and their symmetry axes distribution. The technique has been applied to analyze arrays of submicrometer stripe-shaped Fe ~001! elements with different interelement separations ~s!. For s larger than 1 mm, the anisotropy associated with the stripes is independent on separation, with a value of the effective uniaxial anisotropy constant very consistent with theoretical estimations for these systems. © 2000 American Institute of Physics. @S0003-6951~00!05637-0#