SKM 2023 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 10: Correlated Electrons: Other Materials
TT 10.11: Talk
Monday, March 27, 2023, 17:45–18:00, HSZ 204
Single crystal growth, structural and transport properties of the Mott insulator BaCoS2 — •Haneen Abushammala, Teslin Thomas, Andreas Kreyssig, and Anna Böhmer — Institute for Experimentalphysik IV, Ruhr-Universität Bochum, Universitätsstrasse 150, 44801 Bochum, Germany.
The quasi-2D BaCoS2 is a Mott insulator with a stripe-like antiferromagnetic ordering at TN=290 K. Both chemical doping or hydrostatic pressure drive the system into a paramagnetic metallic phase. Interestingly, there is no structural transition at the metal-insulator transition of this phase, which offers ideal conditions to investigate the Mott transition in a model multiband system [1].
Nevertheless, BaCoS2 remains little studied, and the interplay of electronic and structural features is still unclear. High-quality single crystals are needed to elucidate this issue. The synthesis of single-crystalline BaCoS2 is challenging owing to its metastability, with a decomposition into Ba2CoS3, CoS and S below 850∘C. The BaCoS2 phase can only be obtained via quenching from high temperature. Moreover, BaCoS2 melts incongruently, which calls for a flux growth method necessitating separation of the crystals from the flux by the end of the growth. We have successfully grown single crystals of pure and the hole-doped BaCoS2 using a self-flux method with high-temperature flux separation and quench. The structural and anisotropic electrical transport properties are determined and discussed.
[1] H. Abushammala, B. Lenz, B. Baptiste, M. Casula, Y. Klein and A. Gauzzi, in preparation (2022).