In Situ Observation of Magnetic Anisotropy Energy of Alternately Layered FeNi Thin Films

摘要

Magnetic anisotropy of alternately layered FeNi thin films grown on Ni(3--21 ML)/Cu(001) is investigated by means of the X-ray magnetic circular dichroism (XMCD). Perpendicular magnetic anisotropy is observed when the substrate Ni is thicker than 15 and 20 ML for 4 and 6 ML FeNi films, respectively, while in-plane magnetic anisotropy appears at the thinner substrate Ni region. By comparing with the magnetic phase diagram calculated from the magnetic anisotropy energies, which are obtained by the XMCD study [M. Sakamaki and K. Amemiya, Appl. Phys. Express 4, 073002 (2011)], we show that the phase boundary of the present samples shifts so as to prefer the in-plane magnetic anisotropy. This might be caused by the structural relaxation in the substrate Ni. [DOI: 10.1380/ejssnt.2012.97]