Spectro-Microscopy with aberration correction for relevant techniques
Spectro-Microscopy with Aberration correction for many relevant Techniques
The instrument is an aberration corrected photo-emission electron microscope equipped with an imaging energy analyzer and installed at the high flux density beamline UE49 SMART. The SMART microscope is the first PEEM, showing successfully the simultaneous compensation for spherical and chromatic aberrations, enabling an outstanding lateral resolution of 2.6 nm (LEEM) and 18 nm (energy filtered XPEEM using W4f XPS peak) together with an increase in transmission by a factor of 6, demonstrated under experimental conditions at BESSY-II.
The multitude of operation modes – microscopy, spectroscopy and diffraction of photo-emitted and reflected electrons – and the variety of methods, e.g. photoemission electron microscopy (PEEM), energy-filtered XPEEM, NEXAFS-PEEM, LEEM, NEXAFS, XPS, UPS, XMCD, XMLD, photoelectron diffraction (PED), valence band structure mapping, and LEED, allow for a comprehensive characterization of inhomogeneous surfaces and thin films on nanometer scale with a surface sensitivity of only a few atomic layers. Examples are the local chemical composition of metal nano-particles and of structural domains in thin oxide films, the local molecular orientation of inhomogeneous organic films and local band structure measurements of ordered silica films.
Furthermore, the fast direct (i.e. non-scanning) imaging combined with the possibilities to deposit material on the specimen surface in measurement position, to cool or anneal the sample and to expose the surface to reactive gases during operation enable the in-situ and real time study of complex processes like e.g. film growth, alloying, chemical surface reaction, thermal desorption or phase transition on nanometer scale in video rate with chemical and structural contrast.
|Experiment in vacuum||yes|
|Temperature range||200 - 1800 K|
|Detector||aberration corrected and energy-filtered XPEEM/LEEM system|
|Manipulators||special sample holder design|
|Resolution LEEM||2.6 nm|
|Resolution XPEEM (XPS)||18 nm|
|Energy resolution (XPEEM)||180 meV|
|Base pressure||1e-10 mbar|
|Operation pressure||up to 1e-6 mbar|
|No of ports pointing on sample||8 (4 for evaporators)|
|Sample storage in UHV||6|
|Temperature measurement||W/Re thermocouple of pyrometer|