Layer resolved magnetization dynamics in interlayer exchange coupled Ni81Fe19/Ru/Co90Fe10 by time resolved x-ray magnetic circular dichroism

Abstract

The magnetization dynamics of each layer of interlayer exchange coupled Ni81Fe19/Ru(t)/Co90Fe10 films was investigated by time resolved x-ray
magnetic circular dichroism (TR-XMCD) after pulsed excitation. The
coupling was changed from ferromagnetic to antiferromagnetic by
variation of the Ru thickness t. The precessional motion of the
individual layers was detected separately by measuring the XMCD signal
at the L-3 absorption edge of either nickel or cobalt. From the
observation of two frequency components in the precession of both
layers in samples with negligible interlayer exchange coupling, the
presence of a different coupling mechanism was concluded. Using two
different sample geometries, the influence of antiphase and in-phase
excitation on the triggered dynamics was studied.