Details

Autor(en) / Beteiligte

• Schwarz, Björn
• Ebbinghaus, Stefan G.
• Eichhöfer, Andreas
• Simonelli, Laura
• Krause, Holger
• Bergfeldt, Thomas
• Indris, Sylvio
• Janek, Jürgen
• Ehrenberg, Helmut

Titel

Structure, site symmetry and spin-orbit coupled magnetism of a Ca12Al14O33 mayenite single crystal substituted with 0.26 at.% Ni

Ist Teil von

• Physica. B, Condensed matter, 2023-10, Vol.666, p.415090, Article 415090

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A Ca12Al14O33 mayenite single crystal with 0.26(1) at.% of the metals substituted by Ni was synthesized. Single crystal XRD confirms that about 10 at.% of Al and Ca partially occupy split crystallographic sites with lowered point symmetry. Ni K-edge XAS reveals that Ni is present as Ni2+ and substitutes Al on tetrahedral oxygen coordinated sites. UV-VIS analysis further points to the partial occupation of the trigonally distorted Al(1) and Al(1B) sites by Ni2+. In accordance with the results from the analytical methods, the magnetic model consists of Ni2+ with spin S = 1 on a trigonally distorted tetrahedral coordination site. The J-mulitplet splitting due to spin-orbit coupling with a non-magnetic J = 0 ground state determines the characteristic thermomagnetic properties which show a maximum of the effective paramagnetic moment of 3.61(1) μB at about 191 K and an uniaxial anisotropy (crystal field parameter B02 = 69.5(2) cm−1). [Display omitted] •DC magnetometry and XAS reveal Ni2+ with spin S = 1 positioned on Al sites with tetrahedral oxygen coordination.•Spin-orbit coupling causes a characteristic temperature dependence of magnetization with a paramagnetic moment of 3.61 (1) μB at about 191 K.•Easy-plane magnetic anisotropy indicates that Ni coordination tetrahedra are trigonally distorted in accordance with UV-VIS spectroscopy and XRD.•Magnetic properties are very different from Ca12Al14O33 mayenite with 1 at. % of Al substituted by Fe3+ that behaves free-ion like.