Spin torque oscillator with low magnetic moment and high perpendicular magnetic anisotropy material

摘要

Embodiments disclosed herein generally relate to a magnetic disk device employing a MAMR head. The MAMR head includes an STO. The STO comprises an underlayer, an SPL, and interlayer, an FGL, and a capping layer. The SPL is comprised of a high perpendicular magnetic anisotropy material. The SPL has a large effective perpendicular magnetic anisotropy field, and the SPL has a lower magnetic moment than the FGL. An applied current is adapted to flow in a direction from the FGL to the SPL resulting in the magnetization direction of the SPL being almost perpendicular to the FGL and anti-parallel to a head-gap magnetic field due to a relation between a first spin torque directed from the SPL to the FGL an da second spin torque directed from the FGL to the SPL.