Anisotropy measurements in mesoscopic magnets by magneto-optical torque

The development of a versatile tool to quantify magnetic anisotropies in co ntinuous and patterned magnetic thin films is reported. The technique invol ves measuring the magnetooptic response to a rotating magnetic field. Simil arly to mechanical torque techniques, a single measurement obtains both the anisotropy constants and their symmetry axes distribution. The technique h as been applied to analyze arrays of submicrometer stripe-shaped Fe (001) e lements with different interelement separations (s). For s larger than 1 mu m, the anisotropy associated with the stripes is independent on separation , with a value of the effective uniaxial anisotropy constant very consisten t with theoretical estimations for these systems. (C) 2000 American Institu te of Physics. [S0003-6951(00)05637-0].