スピントルク発振状態における金属ピラーデバイスの磁化状態

抄録

  Both spin-torque oscillation spectra and dV/dI-I curves were measured for a metallic current-perpendicular-to-plane magnetoresistance (CPPGMR) device that had an elliptical nano-pillar shape. The spin-torque oscillation was emitted in a limited magnetic field range near the parallel state when a field was applied to the hard axis of the ellipse. The relative angle was estimated from the dV/dI-I curves for spin torque oscillation state. The relative angle change maintained an intermediate angle between parallel and anti-parallel states with a wide bias current range and the dV/dI-I curve hardly exhibited any hysteresis, peaks, or switching when the device emitted an rf signal. The oscillation frequency was stable against the bias current increase when the change in relative angle change was also stable.