Regensburg 2019 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 26: Materials for Energy Storage and Conversion
MM 26.12: Vortrag
Mittwoch, 3. April 2019, 18:00–18:15, H43
Experimental study on the electronic structure of ZrNiSn half-Heusler thermoelectric material — •Chenguang Fu1, Mengyu Yao1, L. Z. Maulana2, Gudrun Auffermann1, Gerhard Fecher1, M. Dressel2, A. V. Pronin2, and Claudia Felser1 — 1Max Planck Institut für Chemische Physik Fester Stoffe, 01187 Dresden, Germany — 2Physikalisches Institut, Universität Stuttgart, 70569 Stuttgart, Germany
ZrNiSn-based half-Heusler compounds have been developed as good thermoelectric materials in the past decades, which are believed to be attributed to their excellent electrical power factor. However, there is still very few direct experimental investigation of the intrinsic electronic structure for this system, which actually is significant to understand the origin of their excellent thermoelectric properties. In this work, we have successfully grown high-quality undoped and doped ZrNiSn single crystals. With these crystals, we were able to measure their optical reflectivity in the frequency range from 80 cm-1 to 18000 cm-1 and to perform a systematic high-resolution ARPES study on their intrinsic electronic structure. It is found that the band gap of ZrNiSn single crystals is about 0.5 ~ 0.6 eV, which is in agreement with the DFT calculations result, but much larger than the value of 0.2 ~ 0.3 eV previously reported in polycrystalline samples. The possible reasons for this difference will be discussed.