K{sub 7-x-y}Ba{sub y}Nb{sub 14}P{sub 9}O{sub 60} (x = 0.27(5), y = 0.63(3)), a niobium phosphate bronze: Synthesis, structure, and physical properties

Journal Article · Sun Sep 01 00:00:00 EDT 1996 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1996.0285· OSTI ID:486249

Xu, J; Emge, T; Ramanujachary, K V; Hoehn, P; Greenblatt, M ^[1]

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1. State Univ. of New Jersey, Piscataway, NJ (United States)

Large dark blue plate-like single crystals of K{sub 7-x-y}Ba{sub y}Nb{sub 14}P{sub 9}O{sub 60} (x = 0.27(5), y = 0.63(3)) have been synthesized by a solid state technique. A single crystal X-ray diffraction study shows that it crystallizes in the orthorhombic space group Pmma(No. 51) with the lattice parameters a = 36.809(3), b = 10.596(1), and c = 6.459(1) {angstrom} and z = 2. A full matrix least-squares refinement based on 2451 reflections for I > 2{sigma}(I) yielded R(F) = 0.047 and R{sub w}(F{sup 2}) = 0.114. The title compound is isostructural with the previously reported K{sub 7}Nb{sub 14+x}P{sub 9-x}O{sub 60} (x = 0.13). Among the five unique K atoms in the crystal structure of K{sub 7}NB{sub 14.13}P{sub 8.87}O{sub 60}, only K(5) appears to be predominantly substituted by barium. K{sub 6.10}Ba{sub 0.63}Nb{sub 14}P{sub 9}O{sub 60} shows semiconducting behavior with an activation energy of 0.16(1) eV. Magnetic susceptibility measurements on a collection of randomly oriented single crystals indicated Curie behavior with an effective magnetic moment of {mu}{sub eff} = 1.30 {mu}{sub B}/Nb{sup 4+}. A comparison of the structure as well as the electrical transport and magnetic properties of K{sub 6.10}Ba{sub 0.63}Nb{sub 14}P{sub 9}O{sub 60} with that of K{sub 7}Nb{sub 14.13}P{sub 8.87}O{sub 60} is presented.

• OSTI ID: 486249
• Journal Information: Journal of Solid State Chemistry, Vol. 125, Issue 2; Other Information: PBD: Sep 1996
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
POTASSIUM PHOSPHATES
CRYSTAL STRUCTURE
PHYSICAL PROPERTIES
BARIUM PHOSPHATES
NIOBIUM PHOSPHATES
CHEMICAL PREPARATION
ORTHORHOMBIC LATTICES
ACTIVATION ENERGY
STOICHIOMETRY
X-RAY DIFFRACTION
SEMICONDUCTOR MATERIALS
MAGNETIC SUSCEPTIBILITY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0065-0273 K