Determination of the saturation magnetization of ion irradiated Py/Ta samples using polar magneto-optical Kerr effect and ferromagnetic resonance

Based on polar magneto-optical Kerr effect and frequency dependent ferromagnetic resonance measurements, a method has been found that allows for the quantitative determination of the saturation magnetization of samples with unknown effective magnetic volume. Conventional magnetometry cannot be used for this purpose. Thin Py/Ta multilayers with an overall Py thickness of 20 nm but different number of interfaces are used as test systems. By means of Ne ion irradiation the magnetic moment and the saturation magnetization are affected due to interfacial mixing. With both increasing ion fluence and increasing number of Py/Ta interfaces, a decrease of saturation magnetization is observed.