Perpendicular magnetization in ultrathin electrodeposited cobalt films

Electrodeposited ultrathin cobalt films on Au(111) covered with a protective copper film can show perpendicular magnetization exactly like their ultrahigh-vacuum-grown counterparts. At high deposition rates of cobalt, out-of-plane magnetization is stabilized in the thickness range from 2 to 8 atomic layers while low deposition rates favor in-plane magnetization at any thickness. The cobalt films possess hcp structure with the $c$ axis perpendicular to the Au(111) plane. The technique is versatile and leads to quality standards comparable to those obtained by molecular-beam epitaxy, but at a much lower cost.