Microwave generation method and the spin torque oscillator

摘要

PROBLEM TO BE SOLVED: To provide a spin torque oscillator capable of generating a microwave under a low current density.;SOLUTION: The spin torque oscillator includes a nonmagnetic spacer layer 16 having first and second external surfaces, a magnetic field generation layer 33 brought into contact with the first external surface, and a spin injection layer 12 having permanent magnetization perpendicular to the surface of the nonmagnetic spacer layer 16 and brought into complete contact with the second external surface. The magnetic field generation layer 33 has a two-layer structure comprising a first FGL sublayer 331 showing perpendicular magnetic anisotropy and brought into complete contact with the first external surface, and a second FGL sublayer 332 showing in-plane anisotropy and brought into complete contact with the first FGL sublayer 331. Since the two-layer structure in which one layer shows perpendicular magnetic anisotropy and the other layer shows in-plane anisotropy is provided instead of a conventional magnetic field generation layer, making the layer showing perpendicular anisotropy the closest to the nonmagnetic spacer layer 16, a microwave can be generated under a low current density of 1×10⁸A/cm².;COPYRIGHT: (C)2012,JPO&INPIT