Crystal structure and electrical properties of new tungsten bronzes: B {sub x}WO{sub 3} (0.01 {<=} x {<=} 0.08)
- National Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080 (China)
Boron tungsten bronzes B {sub x}WO{sub 3} (0.01 {<=} x {<=} 0.08) were synthesized by hybrid microwave method from mixtures of WO{sub 3} and amorphous boron powder. With the increase of boron content, the crystal structure of B {sub x}WO{sub 3} transforms from orthorhombic (x = 0.01) to tetragonal {alpha} (x = 0.048) and then to tetragonal {beta} (0.07 {<=} x {<=} 0.08). The average size of crystallites is in the range of 1-10 {mu}m. All samples show semiconducting behaviour in their temperature dependence of resistivity. The conduction behaviour above 80 K for samples with x = 0.01 and 0.08 can be explained using the variable-range hopping and thermally activated mechanism, respectively. Comparative experiments showed that boron bronze phases cannot be obtained by the microwave heating of pure WO{sub 3} powder or a mixture of B{sub 2}O{sub 3} and WO{sub 3} under the same conditions.
- OSTI ID:
- 21000676
- Journal Information:
- Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 7 Vol. 42; ISSN MRBUAC; ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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