Dresden 2020 – scientific programme

The DPG Spring Meeting in Dresden had to be cancelled! Read more ...

Parts | Days | Selection | Search | Updates | Downloads | Help

TT: Fachverband Tiefe Temperaturen

TT 42: Correlated Electrons: f-Electron Systems and Heavy Fermions 2

TT 42.8: Talk

Wednesday, March 18, 2020, 17:00–17:15, HSZ 204

Crystallographic structure and magnetism of UNi₄B — •Jannis Willwater¹, Stefan Süllow¹, Milan Klicpera², Michal Valiska², Vladimir Sechovsky², Bachir Ouladdiaf³, and Hiroshi Amitsuka⁴ — ¹IPKM, TU Braunschweig, Germany — ²Department of Condensed Matter Physics, Charles University, Czech Republic — ³Institut Laue-Langevin, France — ⁴Department of Condensed Matter Physics, Japan

The frustrated intermetallic magnet UNi₄B has been reported to crystallize in a hexagonal crystallographic structure and to exhibit a peculiar type of partial magnetic order at low temperatures. Recently, synchrotron x-ray diffraction data have indicated that the structure is orthorhombic and not hexagonal. The best description of the crystal structure at 300 K was obtained with the space group 63 (Cmcm). In this situation, to understand the nature of the magnetic transitions at low temperature, it requires the determination of the low temperature crystallographic symmetry. Therefore, we have studied a ¹¹B enriched single crystal UNi₄B, here using elastic neutron scattering. In our experiment, various structural Bragg peaks forbidden for the Cmcm symmetry have been detected and indicate that the symmetry of the crystal structure is even lower. From fits to our data, we have obtained the best description of the structure with the orthorhombic space group 25 (Pmm2). Further we have detected various magnetic Bragg peaks and established their temperature dependence.