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A new tool for nano-scale x-ray absorption spectroscopy and element-specific SNOM microscopy
|Silvia Larcheri 1, Francesco Rocca 1, Daniel Pailharey 3, Franck Jandard 3, Roberto Graziola 2, Giuseppe Dalba 2, Aleksej Kuzmin 4, Robert Kalendarev 4, Juris Purans 4|
1. CNR-IFN Unita' di Trento, Via alla Cascata, 56/C, Trento 38100, Italy
Investigations of complex nanostructured materials used in modern technologies require special experimental techniques able to provide information on the structure and electronic properties of materials with a spatial resolution down to the nanometer scale. The “X-TIP” STRP project supported by the European Commission under the 6th Framework Programme strove to address these needs through the combination of x-ray absorption spectroscopy (XAS) using synchrotron radiation microbeams with scanning near-field optical microscopy (SNOM) detection of the x-ray excited optical luminescence (XEOL) signal.
The new instrumentation developed within this project offers the possibility to carry out a selective structural analysis of the sample surface with the subwavelength spatial resolution determined by the SNOM probe aperture. In addition, the apex of the optical fibre plays the role of a topographic probe, and chemical and topographic mappings can be simultaneously recorded.
Our working XAS-SNOM prototype is based on: a quartz tuning-fork head mounted on a high stability nano-positioning system; a coated optical fibre tip, operating as a probe in shear-force mode; a detection system (spectrometer with a CCD detector for fast spectral analysis or an analogue detector for imaging) coupled with the microscope head control system; a dedicated software/hardware set-up for synchronization of the XEOL signal detection with the synchrotron beamline acquisition system.In this talk, we will present the state of the art and the new experimental results obtained with the XAS-SNOM prototype operating at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. We will illustrate the possibility to obtain an element-specific contrast and to perform nano-XAS experiments by detecting the Zn K and W L3 absorption edges in luminescent ZnO and ZnWO4 nanostructured thin films.
Presentation: Oral at E-MRS Fall Meeting 2007, Symposium J, by Silvia Larcheri
See On-line Journal of E-MRS Fall Meeting 2007
Submitted: 2007-05-10 17:27 Revised: 2009-06-07 00:44