Structure and Magnetic Properties of SrnCo5, GdCo5, and YCo5Ordered Alloy Films Formed on CR(100) and (211) Underlayers

Nanocomposite magnets consisting of exchange-coupled hard and soft magnetic phases have potentials to achieve high (BH)
_max
. In order to investigate the possibilities, it is usefull to prepare samples of epitaxial thin films, since the easy magnetization axis can be controlled by the substrate orientation. Bulk RCo
₅
(R = Sm, Gd, Y) ordered alloys show K
_u
greater than 10
⁷
erg/cm
³
along the c-axis. In the present study, R
₁₇
Co
₈₃
(at. %) films of 20 nm thickness are prepared on Cr(100) and (211) underlayers hetero-epitaxially grown on MgO substrates by MBE. The structure and the magnetic properties are investigated by RHEED, XRD, VSM, and SQUID.