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P. Weinberger:
"UV-vis-NIR spectroscopy in diffuse reflection and FIR-MIR spectroscopy in ATR-technique as valuable tools for thermo- and magnetochemical investigations";
Vortrag: COSP 2017 (Colloquium Optische Spektroskopie), Bundesanstalt für Materialprüfung Berlin (eingeladen); 27.11.2017 - 29.11.2017; in: "abstracts", (2017).

We work with a Perkin-Elmer Lambda 900 UV-VIS-NIR spectrometer with the "Praying Mantis" ^TM accessory allowing the measurement of powder samples in diffuse reflection technique within the temperature range of 110 K to ambient temperature (see Fig. 1a). The first part of this lecture will present our investigations of thermochemical energy storage materials [1] based on e.g. transition metal salts forming ammoniates and their in-situ characterization by optical spectroscopy of powder samples using the sample chamber as "flow reactor" (see Fig. 1b). The challenges for the measurement set-up will be discussed and possible obstacles and the (partial) solution of problems will be presented.For IR-spectroscopic investigations we work with a Perkin-Elmer Spectrum 400 FIR/MIR spectrometer using a PIKE Gladi-ATR being thermostatable within a temperature range of 100 K to 473K. The second part will be dedicated to the variable temperature measurements of Fe(II) spin crossover complexes [2]. These compounds are characterised structurally, magnetically as well as FIR/MIR spectroscopically. Based on quantum-chemical calculations vibrational modes typical for the low spin state of Fe(II) are identified and their measurements at variable temperature is used for a quantitative determination of the spin state ratio at any temperature measured. (see Fig. 2).

References:
[1] M. Deutsch, D. Müller, C. Aumeyr, C. Jordan, C. Gierl-Mayer, P. Weinberger, F. Winter, A. Werner; Applied Energy, 183 (2016) 113 - 120.
[2] D. Müller, C. Knoll. M. Seifried, P. Weinberger; Vibr. Spectr., 86 (2016) 198 - 205.

thermochemical energy storage materials, spin crossover, UV-vis-NIR, FIR/MIR

http://publik.tuwien.ac.at/files/publik_263670.pdf