Berlin 2008 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 10: Magnetic Materials

MA 10.2: Vortrag

Montag, 25. Februar 2008, 15:30–15:45, H 1028

Temperature induced changes of the Ni electronic structure — •Ruslan Ovsyannikov, Mihaela Gorgoi, Florian Kronast, Hermann A. Dürr, and Wolfgang Eberhardt — BESSY GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany

Temperature dependent changes for surface and bulk states in valence band photoemission are well known [1] and often assigned to an expanding lattice. A similar explanation was proposed for core levels of transition metals such as W [2]. Here we show that the crystalline field is not the only origin of a temperature induced core level shifts. We show using bulk sensitive high kinetic energy photoemission that in the case of Ni a more pronounced temperature effect is visible in core level satellites compared to the main peak. A similar behavior is also observed with XAS. We discuss a model where this behavior can be explained by a reduced hybridization between 3d and 4sp orbitals on neighbor Ni atoms with increasing temperature.

[1] R. Paniago et al., J. Phys.: Condens. Matter 7, 2095 (1995)

[2] H.-S. Tao et al., Phys. Rev. B 56, 6982 - 6986 (1997)