Raman spectrometer with high-performance confocality and mapping

• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 557860503

The aim of this proposal is to ensure a financial support for the purchase of a new Raman spectrometer with high-performance confocality and enhanced 2D and 3D mapping options, operating at two wavelengths (532 and 785 nm), within the DFG programme Major Research Instrumentation (Forschungsgroßgeräte nach Art. 91b GG), as 50% of the price will be covered by the University of Hamburg. Such a Raman system will reduce the workload of the existing Horiba T64000 triple-monochromator Raman system, which has started regularly giving failures of various electronic parts that are not available on the market anymore, and will replace it in the future. The old Horiba T64000 Raman system will continue to be used until it completely becomes out of order, mainly for collecting single-point spectra with visible and UV laser radiation, when an excitation wavelength shorter than 532 nm is required. Thus, most of the research activities of the Department of Earth System Sciences that require the use of Raman spectroscopy will be performed with the new Raman system. As the majority of studied samples are heterogeneous geomaterials, commonly containing structural and/or substitutional defects giving rise to photoluminescence, a Raman system with high-performance confocality (to reduce the undesired photoluminescence background) and enhanced mapping options is required. Such a Raman system will be used for: • studying phase transitions, including in situ mapping of local-scale structural transformations and evolving lower-symmetry domains; • studying chemical gradients and transport phenomena related to reduction-oxidation processes in Fe-bearing rock-forming minerals; • studying residual elastic strain in host-inclusion systems, including in situ studies when the host mineral is under non-ambient conditions; • mineral identification and mineral-grain dispersion in a rock, including samples that commonly exhibit strong photoluminescence, such as marine sedimentary rocks, clays, and geomaterials of biogenic origin; • mapping the chemical zonation within a mineral grain; • mapping the crystal orientation and morphology within a rock sample; • mapping chemical and structural variations in natural glasses, metamict minerals and mineraloids; • mapping plastic deformations of mineral grains across a rock sample; • structural gradients within a mineral grain triggered by temperature, pressure or fluid exposure, including in situ analyses; • studying mineral surface alteration due to weathering, including in situ analyses under mild temperatures in different atmospheres and levels of humidity; • non-destructive analysis of cultural-heritage objects; • characterization of new mineral species.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Raman-Spektrometer mit hochleistungsfähiger Konfokalität und Mapping-Optionen
• Instrumentation Group: 1840 Raman-Spektrometer
• Applicant Institution: Universität Hamburg
• Leader: Professorin Dr. Boriana Mihailova