SKM 2023 – wissenschaftliches Programm
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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur
KFM 6: Poster
KFM 6.10: Poster
Dienstag, 28. März 2023, 17:00–19:00, P3
Thermal Conductivity of CVT Grown FeS2 Crystals Measured by Optothermal Raman Method — •Ayberk Özden1, Esteban Zuñiga Puelles2,3, Jens Kortus1, Roman Gumeniuk2, and Cameliu Himcinschi1 — 1Institut für Theoretische Physik, TU Bergakademie Freiberg, Leipziger Str. 23, 09599 Freiberg, Germany — 2Institut für Experimentelle Physik, TU Bergakademie Freiberg, Leipziger Str. 23, 09599 Freiberg, Germany — 3Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany
In this study, natural mineral and needle-like pyrite crystals grown by chemical vapour transport were selected as model systems and their thermal conductivities were obtained by the optothermal Raman (OTR) method [1]. It is shown that the bulk model used accurately detects differences in the thermal conductivities of mineral and CVT crystals. This difference is attributed to point defects, such as sulphur vacancies or impurity doping. Balkanski-Klemens model analysis showed that three-phonon scattering of Ag and Eg modes and lattice thermal expansion are the dominant anharmonic contributions, while four-phonon scattering is negligible in pyrite-FeS2. Thus, OTR not only provides an easy access to the thermal conductivity of single crystals in their most native form but also sheds light on the underlying phonon scattering mechanisms.
[1]A. Özden, E. Zuñiga-Puelles, J. Kortus, R. Gumeniuk, C. Himcinschi, J. Raman Spectrosc. , DOI:10.1002/jrs.6456.