Berlin 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 42: Thin films – anisotropy

MA 42.3: Vortrag

Donnerstag, 15. März 2018, 10:00–10:15, EB 301

Interrelation of local coordination and magnetism in Fe₆₀Al₄₀ thin films — •A. Smekhova¹, E. La Torre², Th. Szyjka², B. Eggert², B. Cöster², K. Ollefs^2,3, D. Walecki², S. Salamon², R. Bali⁴, J. Lindner⁴, F. Wilhelm³, A. Rogalev³, E. Weschke⁵, D. Többens⁵, R. Banerjee⁶, B. Sanyal⁶, C. Schmitz-Antoniak¹, and H. Wende² — ¹FZ Juelich (PGI-6), Berlin — ²University of Duisburg-Essen and CENIDE, Duisburg — ³ESRF, Grenoble — ⁴HZDR, Dresden — ⁵HZB (BESSY II), Berlin — ⁶Uppsala University, Uppsala

X-ray absorption spectroscopy (EXAFS, XANES, and XMCD) at K and L_2,3 edges of Fe as well as K edge of Al together with synchrotron-based diffraction has been applied to probe local rearrangements and related magnetic and electronic properties of Fe and Al atoms in bare Fe₆₀Al₄₀ thin films through the order-disorder (B2 → A2) phase transition. Distinct changes of Fe and Al coordination resulting in increased Fe 3d spin polarization and characteristic changes in electronic structure of Al due to disordering created by 20 keV Ne⁺ ions of (0.75 - 6)×10¹⁴ ions·cm⁻² fluences have been demonstrated. The preferential in-plane magnetic anisotropy and variations in coercivity fields depending on temperature and irradiation fluence has been found by element-specific hysteresis loops. An attempt to reduce the top oxide layer by an inductively coupled hydrogen plasma has shown that a use of the capping layer could further increase the macroscopic magnetization of films. A theory support was provided by self-consistent DFT calculations using VASP program package.