Flux Synthesis, Crystal Structures, and Magnetic Ordering of the Rare-Earth Chromium(II) Oxyselenides RE2CrSe2O2(RE = La-Nd).
The rare-earth chromium(II) oxyselenides RE2CrSe2O2(RE = La-Nd) were synthesized in eutectic NaI/KI fluxes, and their crystal structures were determined by single-crystal and powder X-ray diffraction (Pb2HgCl2O2-type, C2/m, Z = 2). The magnetic structure of La2CrSe2O2was solved and refined from neutron powder diffraction data. Main building blocks are chains of edge-sharing CrSe4O2octahedra linked together by two edge-sharing ORE3Cr tetrahedra forming infinite ribbons. The Jahn-Teller instability of divalent Cr2+(d4) leads to structural phase transitions at 200 and 130 K in La2CrSe2O2and Ce2CrSe2O2, respectively. RE2CrSe2O2are Curie-Weiss paramagnetic above TN≈ 14-17 K. Neutron powder diffraction reveals anti-ferromagnetic ordering of the Cr2+moments in La2CrSe2O2below TN= 12.7(3) K with an average ordered moment of 3.40(4) μB/Cr2+at 4 K, which was confirmed by muon spin rotation experiments.
Department Chemie, Ludwig-Maximilians-Universität München , D-81377 München, Germany.
Simon
S
Peschke
Department Chemie, Ludwig-Maximilians-Universität München , D-81377 München, Germany.
Valentin
V
Weippert
Heinz Maier-Leibnitz Zentrum, Technische Universität München , Lichtenbergstrasse 1, D-85747 Garching, Germany.
Anatoliy
A
Senyshyn
Heinz Maier-Leibnitz Zentrum, Technische Universität München , Lichtenbergstrasse 1, D-85747 Garching, Germany.|Helmholtz Institute Ulm for Electrochemical Energy Storage , Helmholtzstrasse 11, 89081 Ulm, Germany.|Institut for Applied Materials, Karlsruhe Institute of Technology , Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
Martin Johann
MJ
Mühlbauer
Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, D-48149 Münster, Germany.
Oliver
http://orcid.org/0000-0002-9480-3888
O
Janka
Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, D-48149 Münster, Germany.
Rainer
R
Pöttgen
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute , CH-5232 Villigen PSI, Switzerland.|Physik-Institut der Universität Zürich , Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
Stefan
S
Holenstein
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute , CH-5232 Villigen PSI, Switzerland.
Hubertus
H
Luetkens
Department Chemie, Ludwig-Maximilians-Universität München , D-81377 München, Germany.
Dirk
http://orcid.org/0000-0001-5630-7691
D
Johrendt