Thermal proximity sensing for hard disks
D.W. Abraham, T.J. Chainer, et al.
INTERMAG 2003
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. © 2009 American Institute of Physics.
D.W. Abraham, T.J. Chainer, et al.
INTERMAG 2003
D.C. Worledge, M. Gajek, et al.
IMW 2012
J.Z. Sun, D.W. Abraham, et al.
Applied Physics Letters
J.Z. Sun, P.L. Trouilloud, et al.
Journal of Applied Physics