Preparation and crystal structure of layered niobium oxides: Rb(Mg{sub 0.34}Nb{sub 1.66})O{sub 5} and K(Fe{sub 0.43}Nb{sub 1.57})O{sub 5}

Journal Article · Tue Dec 01 04:00:00 EST 1998 · Materials Research Bulletin

DOI:https://doi.org/10.1016/S0025-5408(98)00186-X· OSTI ID:329095

Kumada, N; Iwase, E; Kinomura, N ^[1]

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1. Yamanashi Univ., Kofu (Japan). Faculty of Engineering

Single crystals of layered niobium oxides, Rb(Mg{sub 0.34}Nb{sub 1.66})O{sub 5} and K(Fe{sub 0.43}Nb{sub 1.57})O{sub 5}, were prepared at 1200 C. The niobium oxides crystallized in the KTiNbO{sub 5}-type structure and have the orthorhombic space group Pnma with Z = 4 and the lattice parameters are a = 6.571(1), b = 3.858(1), and c = 19.077(1) {angstrom} for Rb(Mg{sub 0.34}Nb{sub 1.66})O{sub 5}, and a = 6.533(1), b = 3.820(2), and c = 18.682(2) {angstrom} for K(Fe{sub 0.43}Nb{sub 1.57})O{sub 5}. The single-crystal structure refinements led to R = 0.032 and R{sub w} = 0.031 for Rb(Mg{sub 0.34}Nb{sub 1.66})O{sub 5} and to R = 0.049 and R{sub w} = 0.064 for K(Fe{sub 0.43}Nb{sub 1.57})O{sub 5}. The niobium and iron/magnesium atoms are statistically distributed in a unit of doubled octahedra sharing edges. Alkaline ions in the interlayer were ion exchanged with protons to yield hydrated protonated compounds, H(M,Nb){sub 2}O{sub 5}{center_dot}nH{sub 2}O (M = Mg,Fe).

• OSTI ID: 329095
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 12 Vol. 33; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL STRUCTURE
CRYSTALLIZATION
IRON OXIDES
LATTICE PARAMETERS
LAYERS
MAGNESIUM OXIDES
MONOCRYSTALS
NIOBIUM OXIDES
POTASSIUM OXIDES
RUBIDIUM OXIDES