Investigation of Fe/Al multilayers

Abstract The effect of number of layers in Fe(25 A)/Al(25 A) multilayer samples is studied using ferromagnetic resonance (FMR) and magnetization measurements. It is observed that more than four bilayers of Fe/Al give rise to two to three resonances, out of which one is a common/main one and occurs at about 900 Oe. Using the main resonance, effective magnetization M eff has been deduced from FMR and is found to be about 1 2 of the value of saturated magnetization, M s , of bulk iron. Magnetization measurements also give similar reduced value of magnetization M but a little larger value. Temperature dependence of M , i.e., M ( T ) shows a peak in zero-field-cooled samples, while no such peak is observed in field-cooled M ( T ). M ( T ) can be fitted to T 3/2 dependence in RT—100 K region whether M is derived from FMR or magnetization measurements. FMR and magnetization measurements indicate antiferromagnetic interlayer coupling between iron films may be coexisting with the ferromagnetic interaction within each iron film.