New technique to measure magnetic anisotropy using the vectorial magneto-optic Kerr effect

A new method of interpreting the data produced by vectorial magnetometry using the magneto-optic Kerr effect (MOKE) is described. The procedure allows the angle between the magnetisation and the applied held to be measured independently of the applied field. Rotation of the sample generates a curve similar to that produced by a torque magnetometer. The technique is applied to sputtered Si/Co/Cr/Co trilayers, and the curves are analysed using a fitting method to measure the ratio of the magnetisation to the uniaxial anisotropy constant, providing an insight into the effects of thermal annealing on the samples.