Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 48: Topological Semimetals - Experiment (joint session TT/MA)
MA 48.4: Vortrag
Donnerstag, 4. April 2019, 15:45–16:00, H2
Dirac semimetal PtBi2: polymorphism and challenges in crystal growth — •Grigory Shipunov, Boy Roman Piening, Saicharan Aswartham, and Bernd Büchner — IFW-Dresden, Dresden, Germany
PtBi2 is showing rich polymorphism, with at least 3 different crystal structures corresponding to this composition are reported. At least two of this structures, pyrite-type cubic (space group Pa3) and hexagonal (space group P31m), are showing linearly dispersive Dirac states and anomalous transport properties, such as extremly large linear magnetoresistance.
Here, we present our results on targeted crystal growth of cubic or hexagonal modification. Cubic and hexagonal modifications were grown via self-flux method, with growth parameteres such as Pt:Bi ratio and temperature profile chosen based on thermodynamical phase diagram data. High quality of the crystals is confirmed by powder and single crystal x-ray diffraction and scanning electron microscopy with energy dispersive x-ray spectroscopy techniques. Optimization of the growth parameters for the metastable trigonal polymorph is also discussed.