KIT | KIT-Bibliothek | Impressum | Datenschutz

Incommensurate magnetic structure of CrAs at low temperatures and high pressures

Eich, Andreas; Grzechnik, Andrzej; Su, Yixi; Ouladdiaf, Bachir; Sheptyakov, Denis; Wolf, Thomas 1; Petricek, Vaclav; Shahed, Hend; Friese, Karen
1 Institut für QuantenMaterialien und Technologien (IQMT), Karlsruher Institut für Technologie (KIT)

Abstract:

The magnetic structure of chromium arsenide CrAs is studied with neutron powder diffraction at ambient pressure in the temperature range 1.5–300 K as well as with neutron single-crystal diffraction at 2 K and 0.12 GPa. The material undergoes an anti-isostructural phase transition at TN = 267 K and atmospheric conditions, in which both orthorhombic phases have the same space-group symmetry (Pnma, Z = 4) but different distortions of the parent hexagonal structure of the NiAs type (P63/mmc, Z = 2). The magnetic structure below TN is incommensurate with the propagation vector k = (0, 0, kc). At ambient pressure, the component kc decreases from kc = 0.3807 (7) at 260 K to kc = 0.3531 (6) at 50 K. Below this temperature, it is basically constant. With increasing pressure at 2 K, kc is also constant within standard uncertainties [kc = 0.353 (2)]. For the analysis of the magnetic structure, a group-theoretical approach based on the space group of the nuclear structure and its subgroups is used. To avoid falling into false minima in the refinements, a random search for magnetic moments in the models is implemented. In the literature, the magnetic structure has been determined on the basis of powder diffraction data as a double helix propagating along the c axis. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000163309
Veröffentlicht am 23.10.2023
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für QuantenMaterialien und Technologien (IQMT)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 01.12.2023
Sprache Englisch
Identifikator ISSN: 2052-5206
KITopen-ID: 1000163309
HGF-Programm 47.11.02 (POF IV, LK 01) Emergent Quantum Phenomena
Erschienen in Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials
Verlag John Wiley and Sons
Band 79
Heft B
Seiten 473-481
Vorab online veröffentlicht am 12.10.2023
Schlagwörter incommensurate magnetic structure; neutron diffraction; extreme conditions; high pressure.
Nachgewiesen in Web of Science
Dimensions
Scopus
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page