Regensburg 2013 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
MA: Fachverband Magnetismus
MA 8: Spin Excitations and Spin Torque
MA 8.6: Talk
Monday, March 11, 2013, 10:45–11:00, H23
Thermally Excited Ferromagnetic Resonance in MgO-based Magnetic Tunnel Junctions — •Ewa Kowalska1, Yuriy Aleksandrov1,2, Kerstin Bernert1,2, Ciaran Fowley1, Volker Sluka1, Jürgen Lindner1, Jürgen Fassbender1,2, and Alina Deac1 — 1HZDR, Dresden, Germany — 2TU Dresden, Germany
Spin polarized currents can exert a so-called spin-transfer torque to the magnetic moment of a ferromagnetic layer. One application of this phenomenon is the spin torque nano-oscillator (typically an MgO-based magnetic tunnel junction (MTJ)) which can act as a tunable microwave emission source. However, a more detailed understanding of the spin-torque physics is needed. For example, the spin torque bias dependence of the two spin torque components (in-plane and field-like) is still widely discussed in the community [1]. We present results for MgO-MTJs obtained by thermally excited ferromagnetic resonance (TE-FMR). With the help of TE-FMR, the bias dependence of the two spin-transfer torques can be determined from the peak position and linewidth [2]. Microwave measurements were carried out in the frequency range of 1-9 GHz at positive and negative magnetic fields and for different dc current values. Analyzing this data, we could separate the in-plane and field-like spin torque components and determine their bias dependence.
[1] M. H. Jung et al., PRB 81, 134419 (2010).
[2] A. Deac et al., Nature Phys. 4, 803 (2008).