Abstract: Hard magnetic recording disks include a rigid substrate, typically aluminum, ceramic, or glass, having an underlayer thereover, typically being nickel-phosphorus. A ferromagnetic film is formed over the underlayer, and a protective coating layer formed over the ferromagnetic layer. The protective coating layer is a metal oxide formed by applying a liquid metal oxide precursor material over the ferromagnetic layer, and curing the liquid precursor material to leave a metal oxide layer in place. Optionally, a lubricating or carbon layer may be formed over the protective layer.