International Collaboration in Chemistry: Novel Instrumentation for Modern Elemental Speciation Analysis

• Applicants: Dr. Wolfgang Buscher; Dr. Volker Hoffmann
• Subject Area: Analytical Chemistry
• Term: from 2008 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 84887454

The surface composition of a solid has a profound influence on its chemical, physical and material properties. This is because many important phenomena (e.g. optical interaction, electron transfer, etc.) are localized at the solid interface; thus, elucidating the composition of the surface layers is crucial to understanding a host of chemical and physical behaviors, as well as informing the construction of new materials. The aim of this proposal is the continued development of a novel, simple, general, and relativer/ inexpensive analytical instrument capable of providing new surface analysis capabilities. Specifically, the instrument employs atomic-emission spectrometry (AES) for the elemental analysis of solid materials with three dimensional spatial resolution. A novel pulsed glow discharge (GD) is used to sputter atoms from the surface of conductive, semiconductor, or insulator samples, and subsequently excite them to be detected by AES. The GD provides depth-profiling analysis of the surface with nanometer resolution by progressively sputtering away surface material and analyzing the constituent atoms. The pulsed GD provides lateral spatial resolution by restricting the distance agas-phase atom travels from the point from which it was initially sputtered before it is excited and detected. The ultimate result of this novel GD-AES analysis is then a 3-dimensional (3-D) multi elemental emission map revealing the location, type, and quantity of atoms within the solid sample. Studies conducted under prior NSF and DFG support have verified the viability of such an instrument. For further details, e.g. applications in biomolecule and structured materials analyses, see NSF part of the application.

• DFG Programme: Research Grants
• International Connection: USA
• Major Instrumentation: Acousto-optical Imaging Spectrometer and Camera System ; Monochromator and Camera System
• Instrumentation Group: 1800 Spektralphotometer (UV, VIS), Spektrographen (außer Monochromatoren 565) ; 5650 Monochromatoren (außer Röntgen- 405)
• Participating Persons: Professor Dr. Carsten Engelhard; Professor Dr. Gary M. Hieftje