In one embodiment, a magnetic storage device includes at least one microwave assisted magnetic recording (MAMR) head, each MAMR head including a spin torque oscillator (STO), a magnetic recording medium, a drive mechanism for passing the magnetic medium over the at least one MAMR head, and a controller electrically coupled to the at least one MAMR head for controlling operation of the at least one MAMR head, wherein the magnetic recording medium includes a recording layer positioned directly or indirectly above a substrate and an assist layer positioned above the recording layer, wherein the recording layer includes at least Co, Pt, and an oxide or oxygen, wherein the assist layer is positioned closer to the at least one MAMR head and includes at least Co and Pt, and wherein at least a portion of the recording layer has a smaller anisotropic magnetic field than the assist layer.