Field and bias dependence of high-frequency magnetic noise in MgO-based magnetic tunnel junctions
2009
We present room-temperature measurements of high-frequency magnetization fluctuation (mag noise) in MgO-based nanopillar magnetic tunnel junctions (MTJs) biased with a direct current (dc). In the frequency range of 1–13 GHz, double mag-noise peaks are observed for some MTJs while others only show a single mag-noise peak. The in-plane field dependence of the mag-noise peak frequency is consistent with the Kittel formula. For all MTJs measured, the bias-dependent shift in the mag-noise peak frequency has a pronounced asymmetry. In addition, we find nonmonotonic variations in peak linewidth as a function of the external in-plane magnetic field and of the dc bias current. These suggest the possible involvement of nonmacrospin modes in spin-torque-dependent thermal mag-noise generation.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
14
References
12
Citations
NaN
KQI