Experimental confirmation of the delayed Ni demagnetization in FeNi alloy

Element-selective techniques are central for the understanding of ultrafast spin dynamics in multi-element materials like magnetic alloys. Recently, though, it turned out that commonly used technique transverse magneto-optical Kerr effect (T-MOKE) EUV range may have linearity issues including unwanted cross talk between different elemental signals. This problem can be sizeable, which puts recent observations transfer from Fe to Ni sites FeNi alloys into question. In this study, we investigate Fe-to-Ni a cross-talk-free time-resolved X-ray circular dichroism (XMCD) experiment with reliable time reference. We find very similar and XMCD as T-MOKE identical samples. Considering non-linearities response, agreement our findings appears fortuitous. discuss possible reasons why seems give accurate results case. Our data provide ongoing discussion about spin-transfer mechanisms systems sound experimental basis.