Magnetic properties versus interface density in rigid-exchange-coupled amorphous multilayers with induced uniaxial anisotropy

We demonstrate the possibility to tune the saturation magnetization, coercivity, and uniaxial in-plane anisotropy constant in amorphous bilayers and multilayers of Co-85(Al70Zr30)(15) and Sm11Co82Ti7 through the interface density. From magnetometry and x-ray circular dichro-ism (XMCD) measurements, we conclude that the easy-axis coercivity mu H-0(c) increases four times when the number of bilayer repetitions, N, increases from 1 to 10 within a constant total sample thickness of 20 nm. At the same time, the anisotropy constant K-u also increases by a factor four, whereas the saturation magnetization M-s decreases slightly. The Co spin and orbital moments, m(s) and m(l), are found to be approximately constant within the sample series. The average total Co moment is only 0.8-0.9 mu(B)/atom, but the m(l)/m(s) ratio is strongly enhanced compared to pure Co. Magnetization curves extracted from XMCD measurements show that the Co and Sm moments are ferro-magnetically coupled for all samples. (c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).