title: "114"-Type Nitrides LnAl(Si4-xAlx)N7Oδwith Unusual [AlN6] Octahedral Coordination.
abstract: Aluminum-nitrogen six-fold octahedral coordination, [AlN6], is unusual and has only been seen in the high-pressure rocksalt-type aluminum nitride or some complex compounds. Herein we report novel nitrides LnAl(Si4-xAlx)N7Oδ(Ln=La, Sm), the first inorganic compounds with [AlN6] coordination prepared via non-high-pressure synthesis. Structure refinements of neutron powder diffraction and single-crystal X-ray diffraction data show that these compounds crystallize in the hexagonal Swedenborgite structure type with P63mc symmetry where Ln and Al atoms locate in anticuboctahedral and octahedral interstitials, respectively, between the triangular and Kagomé layers of [SiN4] tetrahedra. Solid-state NMR data of high-purity La-114 powders confirm the unusual [AlN6] coordination. These compounds are the first examples of the "33-114" sub-type in the "114" family. The additional site for over-stoichiometric oxygen in the structure of 114-type compounds was also identified.
authors.affiliation: School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing, 100083, P.R. China.|Department of Chemical & Materials Engineering, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Saifang
authors.identifier: 0000-0002-4315-4494
authors.initials: S
authors.lastname: Huang
authors.affiliation: School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing, 100083, P.R. China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Chemical & Materials Engineering, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Peng
authors.identifier: 0000-0001-6390-6852
authors.initials: P
authors.lastname: Cao
authors.affiliation: School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Zoran
authors.identifier: 0000-0002-3852-6126
authors.initials: Z
authors.lastname: Zujovic
authors.affiliation: Australian Synchrotron, 800 Blackburn Road, Clayton, VIC 3168, Australia.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Price
authors.affiliation: Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia.
authors.forename: Maxim
authors.identifier: 0000-0003-2366-5809
authors.initials: M
authors.lastname: Avdeev
authors.affiliation: School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, 710049, P.R. China.
authors.forename: Meidan
authors.initials: M
authors.lastname: Que
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan.
authors.forename: Furitsu
authors.initials: F
authors.lastname: Suzuki
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kido
authors.affiliation: School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing, 100083, P.R. China.|Department of Chemical & Materials Engineering, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Xin
authors.initials: X
authors.lastname: Ouyang
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Kaji
authors.affiliation: School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing, 100083, P.R. China.
authors.forename: Minghao
authors.initials: M
authors.lastname: Fang
authors.affiliation: School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing, 100083, P.R. China.
authors.forename: Yan-Gai
authors.initials: YG
authors.lastname: Liu
authors.affiliation: Department of Chemical & Materials Engineering, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Wei
authors.identifier: 0000-0002-5064-0917
authors.initials: W
authors.lastname: Gao
authors.affiliation: School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Tilo
authors.identifier: 0000-0003-4472-5807
authors.initials: T
authors.lastname: Söhnel
keywords: NMR spectroscopy; [AlN6] octahedron; aluminum; nitrides; structure elucidation