Preparation and crystal structure of new potassium niobium oxides: K{sub 2}M{sub 2}Nb{sub 4}O{sub 13} (M = Mg,Fe)
Journal Article
·
· Materials Research Bulletin
- Yamanashi Univ., Kofu (Japan). Faculty of Engineering
Single crystals of new niobium oxides, K{sub 2}M{sub 2}Nb{sub 4}O{sub 13} (M = Mg,Fe) were prepared at 1,200 C. These niobium oxides crystallize in the K{sub 2}Ti{sub 6}O{sub 13}-type structure and have the monoclinic space group C2/m and Z = 2. The lattice parameters were a = 16.028(6), b = 3.885(3), c = 9.473(3){angstrom} and {beta} = 99.26(3){degree} for M = Mg, and a = 16.095(2), b = 3.886(2), c = 9.474(1){angstrom} and {beta} = 99.62(1){degree} for M = Fe. The final R-factors were R = 0.046 and Rw = 0.044 for 2,142 unique reflections for M = Mg, and R = 0.026 and Rw = 0.029 for 2,144 unique reflections for M = Fe. These niobium oxides are the first example of niobium oxides with the K{sub 2}Ti{sub 6}O{sub 13}-type structure. The niobium and magnesium atoms are statistically distributed in triple octahedra sharing edges in K{sub 2}Mg{sub 2}Nb{sub 4}O{sub 13}, and in contrast the iron atom is located in one of triple octahedra sharing edges in K{sub 2}Fe{sub 2}Nb{sub 4}O{sub 13}.
- OSTI ID:
- 509194
- Journal Information:
- Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 5 Vol. 32; ISSN MRBUAC; ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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