Ortsaufgelöste oder topochemische Analytik — ein Überblick

Possibilities of space-resolved solid-state speciation

“…The methods are grouped in the usual way as photon-or electron-probe techniques. 5,6 Ion probe techniques and stylus techniques do not generally carry information on speciation. However, under special circumstances, hints to speciation can be obtained.…”

“…With the advent of well focussed laser beams as sources for the excitation of Raman spectra and parallel developments in relevant instrumentation, respective space-resolved analysis with a lateral resolution of 1 mm and a depth resolution of 0.1 mm has become possible. 5,9 Confocal imaging techniques now provide solutions to circumvent the limitations in optical lateral resolution. Although scanning near-field optical microscopy (SNOM) was originally developed as the optical ''cousin'' of scanning probe microscopies, one of its essential characteristics is its ability to deliver a continuous or pulsed laser beam to a spot size of 30-100 nm.…”

“…XPS is the most commonly used method of solid-state speciation. 5,6,15 It is used for elemental analysis of surfaces of all elements except hydrogen. Its greatest strength, however, is the identification of chemical states of surface species.…”

“…The latter is one of the major techniques for electronic structure analysis of solid surfaces and for the characterization of adsorbates. 5,16 2.1.4 Notes to techniques based on X-rays and synchrotron radiation. The unique properties of synchrotron radiation (SR) generated by modern SR-sources coupled with developments of X-ray optical elements and detectors offer excitingly new possibilities in X-ray microscopy and microprobe methods both in terms of achievable spatial resolution and sensitivity.…”

“…These methods have been in use in materials characterization and biological studies for quite some time. 4,5,9,20 Reduced size beams will bring the technique to the nanoscopic observation domain as discussed above. 21,22 While EXAFS uses an energy region extending from 50 to as much as 1500 eV above the K-absorption edge of the probed element, XANES analyses the region within B50 eV of the absorption edge.…”