Dresden 2014 – scientific programme
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MA: Fachverband Magnetismus
MA 43: Magnetization Dynamics III
MA 43.5: Talk
Thursday, April 3, 2014, 16:00–16:15, HSZ 401
Spin waves in ultrathin hexagonal Cobalt films — •Eugen Michel1,2, Jayaraman Rajeswari1,2, Harald Ibach1,2, and Claus M. Schneider1,2 — 1Peter-Grünberg-Institut, Forschungszentrum Jülich, 52425 Jülich, Germany — 2Jülich Aachen Research Alliance, Germany
As previous publications [1,2] have shown electron energy loss spectroscopy is a promising tool for studies of large wave vector spin waves in the surface and thin film region. Using our high-resolution spectrometer [3] we have probed the dispersion of spin waves in hexagonal Co-films grown on Cu(111) and Au(111) single crystal surfaces. The film thicknesses ranged from 3 to 18 atomic layers (AL). For Co grown on Cu(111) we have observed surface spin wave signatures with wave vectors in the range of q = 2 - 8 1/nm. Furthermore we have resolved standing wave modes for film thicknesses between 3AL and 5AL. The results are compared to theoretical calculations based on the Heisenberg model with adjusted exchange coupling constants. The spin wave spectra from films grown on Au(111) exhibit a significant broadening, which is attributed to the higher disorder of the Co-films. The spectra can be simulated taking the experimentally determined wave vector resolution into account.
[1] R. Vollmer et al., JMMM 272-276, (3), pp 2126-2130 (2004).
[2] J. Rajeswari et al., Phys. Rev. B 86, 165436 (2012).
[3] H. Ibach et al., JESRP 185, 3 - 4, pp 61-70 (2012).