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 1.2 MJ/m ³) and hard magnetic properties (coercivity up to 358.2 kA/m) in a wide thickness range, from 5 to 2000 nm. Crystalline, magnetoelastic, and interface effects are discussed as possible origins of the observed perpendicular anisotropy.