Séminaire du vendredi 11 février 2011 à 11h

Institut de Minéralogie et de Physique des Milieux Condensés

Université P. et M. Curie, 4, Place Jussieu, 75005 Paris

Salle de Conférence (401),

4ème étage, Tour 23, couloir 22-23

 X-ray spectroscopy: New developments in theory and experiment

Frank de Groot
Debye Institute of Nanomaterials Science
(Utrecht University, Netherlands)

http://www.anorg.chem.uu.nl/people/staff/FrankdeGroot/index.htm

 
New developments in x-ray absorption spectroscopy and resonant inelastic x-ray scattering will be discussed. First an introduction is given of x-ray absorption spectroscopy, including the multiplet interpretation of XAS spectral shapes [1,2]. Examples are given from the use of X-ray magnetic circular dichroism (X-MCD) [3] and the effects of pi-bonding on iron complexes [4]. With the recent developments in nanoreactors, scanning transmission x-ray microscopy (STXM) experiments make it possible to follow metal L edges at 1 bar and 500 C, with a spatial resolution of 20 nm. This allows the in-situ spectroscopic study of a single nanoparticle (in action) [5]. A comparison will be made between x-ray and electron spectromicroscopy and some future directions of spectromicroscopy of nanomaterials are given. [6,7]. The last part of the talk deals with the role of resonant inelastic x-ray scattering (RIXS) to unravel the nature of the surface of small metal nanoparticles.


[1]   Core Level Spectroscopy of Solids
Frank de Groot and Akio Kotani (Taylor & Francis CRC press, 2008)

[2]   Download the x-ray spectroscopy simulation software at  http://www.anorg.chem.uu.nl/CTM4XAS/

[3] P. Gambardella et al. Nature Materials 8, 189 (2009)

[4] R. Hocking et al. J. Am. Chem. Soc. 128, 10442 (2006) & 129, 113 (2007)

[5] E. de Smit et al. Nature 456, 222 (2008)

[6] F.M.F. de Groot et al. ChemPhysChem 11, 951 (2010)
[7] M. van Schooneveld et al. Nature Nanotechnology 5, 538 (2010)