Regensburg 2013 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 22: Poster II

DF 22.18: Poster

Friday, March 15, 2013, 10:30–13:30, Poster D

FMR and MOKE characterization of Co₄₀Fe₄₀B₂₀ thin films — •Andres Conca, Jochen Greser, Thomas Sebastian, Stefan Klingler, Britta Leven, and Burkard Hillebrands — FB Physik und Landesforschungszentrum OPTIMAS, TU Kaiserslautern, 67663 Kaiserslautern, Germany

Magnetic tunneling junctions are being widely used for read heads in hard discs, sensors in robotics or machine controllers. A major breakthrough was provided by the introduction of the alloy CoFeB. With a control of the exact stack composition and of the annealing conditions tunelling magnetoresistance ratios (TMR) as large as 604% [1] have been reported.

Here, we report on the characterization of Co₄₀Fe₄₀B₂₀ thin films deposited by magnetron rf-sputtering on SiO_x substrates. The dynamic properties and material parameters were studied by measuring the ferromagnetic resonance using a stripline-vector network analyzer (VNA-FMR). The quasi-static anisotropic switching properties were measured with a magneto-optical Kerr effect setup in longitudinal geometry with a rotational sample stage. A discussion of the values of the saturation magnetization, the Gilbert damping parameter and the exchange constant is presented.

Financial support by the MBWWK of Rhineland-Palatinate and the EFRE programm in the frame of the Spin Technology Platform (STeP) is gratefully acknowledged.

[1] S. Ikeda, et al, Appl. Phys. Lett. 93, 082508 (2006).