Patent ID: 8755150
Filing Date: 2014-06-17
Classification: G11B

Abstract:
1. A microwave assisted magnetic recording (MAMR) structure that includes a write head, comprising: (a) a main pole that generates a magnetic flux field which is directed through a pole tip at an air bearing surface (ABS) and into a magnetic medium comprised of a plurality of bits, the magnetic flux has a gap field component that is directed across a spin torque oscillator (STO) and into a write shield; (b) the write shield with a side along the ABS that collects magnetic flux which passes through the magnetic medium and writes one or more bits; (c) the STO that is formed along the ABS and has a NM1/OL/NM3/SP/NM2 configuration wherein a first non-magnetic layer (NM1) adjoins the main pole, a second non-magnetic layer (NM2) contacts the write shield, SP is a layer with perpendicular magnetic anisotropy that spin polarizes direct current (dc) and radio frequency (rf) current passing there through, NM3 is a third non-magnetic layer between SP and OL layers, and OL is a layer with a magnetization that reaches a large angle oscillation state with an oscillation frequency when a threshold current with density (j (d) a bias tee (T) that is electrically connected by a lead to the main pole and by a lead to the write shield, and combines dc from a dc source and rf current from a rf current source and injects the dc and rf current combination into the STO through a main pole terminal or a write shield terminal to provide a dc bias, and a rf bias to the STO.