New scheelite-type oxynitrides in systems RWO{sub 3}N-AWO{sub 4} (R = rare-earth element; A = Ca, Sr) from precursors obtained by the citrate route

Journal Article · Tue Jun 08 00:00:00 EDT 2004 · Materials Research Bulletin

DOI:https://doi.org/10.1016/j.materresbull.2004.02.016· OSTI ID:20888081

Chevire, Francois; Tessier, Franck; Marchand, Roger

RWO{sub 3}N oxynitrides were isolated as single phases for R=Nd and Pr, after thermal ammonolysis of reactive precursors prepared using the citrate complexation/calcination route. Both stoichiometric compounds crystallize with a scheelite-type tetragonal unit cell, with a=5.2821(3) A, c=11.5893(8) A (NdWO{sub 3}N) and a=5.299(3) A, c=11.631(9) A (PrWO{sub 3}N). Neutron diffraction experiments performed on the Nd-phase did not evidence any oxygen/nitrogen order within the scheelite anionic subnetwork (space group: I4{sub 1}/a). (Nd,A)W(O,N){sub 4} (A=Ca, Sr) solid solution domains were identified between NdWO{sub 3}N and the AWO{sub 4} oxide composition.

• OSTI ID: 20888081
• Journal Information: Materials Research Bulletin, Vol. 39, Issue 7-8; Other Information: DOI: 10.1016/j.materresbull.2004.02.016; PII: S0025540804000571; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMMONOLYSIS
CALCINATION
CHEMICAL PREPARATION
CITRATES
CRYSTAL STRUCTURE
NEUTRON DIFFRACTION
NITRIDES
OXIDES
RARE EARTHS
SOLID SOLUTIONS
SPACE GROUPS
STOICHIOMETRY
TETRAGONAL LATTICES