Ba3(Cr0.97(1)Te0.03(1))2TeO9: in Search of Jahn-Teller Distorted Cr(II) Oxide.
A novel 6H-type hexagonal perovskite Ba3(Cr0.97(1)Te0.03(1))2TeO9was prepared at high pressure (6 GPa) and temperature (1773 K). Both transmission electron microscopy and synchrotron powder X-ray diffraction data demonstrate that Ba3(Cr0.97(1)Te0.03(1))2TeO9crystallizes in P63/mmc with face-shared (Cr0.97(1)Te0.03(1))O6octahedral pairs interconnected with TeO6octahedra via corner-sharing. Structure analysis shows a mixed Cr2+/Cr3+valence state with ∼10% Cr2+. The existence of Cr2+in Ba3(Cr2+0.10(1)Cr3+0.87(1)Te6+0.03)2TeO9is further evidenced by X-ray absorption near-edge spectroscopy. Magnetic properties measurements show a paramagnetic response down to 4 K and a small glassy-state curvature at low temperature. In this work, the octahedral Cr2+O6component is stabilized in an oxide material for the first time; the expected Jahn-Teller distortion of high-spin (d4) Cr2+is not found, which is attributed to the small proportion of Cr2+(∼10%) and the face-sharing arrangement of CrO6octahedral pairs, which structurally disfavor axial distortion.
Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey , 610 Taylor Road, Piscataway, New Jersey 08854, United States.
Man-Rong
MR
Li
Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey , 610 Taylor Road, Piscataway, New Jersey 08854, United States.
Zheng
Z
Deng
Advanced Photon Source, Argonne National Laboratory , Lemont, Illinois 60439, United States.
Saul H
SH
Lapidus
Department of Physics & Astronomy, State University of New York , Stony Brook, New York 11794, United States.
Peter W
PW
Stephens
Department of Physics & CSRRI, Illinois Institute of Technology , 3300 South Federal Street, Chicago, Illinois 60616, United States.
Carlo U
CU
Segre
Department of Physics and Astronomy, Rutgers, The State University of New Jersey , 136 Frelinghusen Road, Piscataway, New Jersey 08854, United States.
Mark
M
Croft
EMAT, University of Antwerp , Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
Robert
R
Paria Sena
EMAT, University of Antwerp , Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
Joke
J
Hadermann
Lamont Doherty Earth Observatory, Columbia University , 61 Route 9W, PO Box 1000, Palisades, New York 10964, United States.
David
D
Walker
Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey , 610 Taylor Road, Piscataway, New Jersey 08854, United States.
Martha
M
Greenblatt