First principles investigation of the crystal and electronic structures of CeNCl and “CeNF”
Language
en
Article de revue
This item was published in
Solid State Sciences. 2015, vol. 48, p. 1-6
Elsevier
English Abstract
Based on DFT energy discrimination and detailed electronic and bonding properties, it is shown that the hitherto unexplored cerium nitride fluoride can be obtained in rhombohedral ThNF structure whereas actual CeNCl is ...Read more >
Based on DFT energy discrimination and detailed electronic and bonding properties, it is shown that the hitherto unexplored cerium nitride fluoride can be obtained in rhombohedral ThNF structure whereas actual CeNCl is confirmed in the early determination PbFCl-like structure. The respectively adopted 3D and 2D like structures are assigned to the major role played by the F polarizability, four times smaller than Cl. In their ground state both compound are found small gap insulators with 1.9 eV (CeNCl), 1.8 eV (CeNF) compared to insulating isoelectronic cerine CeO2 with 2.2 eV band gap. The bonding shows balance between covalence brought by Ce–N bond versus ionic Ce–F(Cl) bonding and d(Ce–N) < d(Ce–F(Cl)) distances. Synthesis routes for CeNF are proposed.Read less <
English Keywords
Mixed-anions
crystal structure
iono-covalent
DFT
COOP 2
Origin
Hal imported