Perpendicular anisotropy in electrodeposited, Co-rich Co–Pt films by use of Ru underlayers

Co-rich Co–Pt alloys were electrodeposited from an amino-citrate-based solution on a Si $(011)∕Cu(111)∕Ru(0001)$ seed layer. Such a template provides an appropriate interface structure for the growth of a (0002)-oriented hexagonal phase, stabilized at larger thickness by the electrolyte chemistry, providing for a columnar structure with no detectable grain coarsening. This results in as-deposited Co–Pt films exhibiting perpendicular anisotropy (anisotropy constant up to $1.2MJ∕m3$⁠) and hard magnetic properties (coercivity up to $358.2kA∕m$⁠) in a wide thickness range, from $5to2000nm$⁠. Crystalline, magnetoelastic, and interface effects are discussed as possible origins of the observed perpendicular anisotropy.