Patent ID: 8605391

Claim:
A magnetic head comprising: a main magnetic pole; a write-shield constituting a magnetic circuit with the main magnetic pole; and a spin torque oscillation element having a first oscillation layer, a nonmagnetic spin sink layer containing at least one element selected from the group consisting of Ru, Rh, Ta, W, Cr, Ir, Mo, Re, Nb, Pt, and Pd, a second oscillation layer, a nonmagnetic intermediate layer, and a spin injection layer, wherein a relationship represented by the following formulae (1) and (2) is satisfied: 0.1 <t 2 , and 0.1 <t 1 . . . (1) Ms 1 t 1 >Ms 2 t 2 . . . (2), where t 1 represents a thickness (nm) of the first oscillation layer, t 2 represents a thickness (nm) of the Second oscillation layer, Ms 1 represents saturated magnetization of the first oscillation layer, and Ms 2 represents saturated magnetization of the second oscillation layer.