ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Temperature dependence of lattice parameters of bismuth sesquioxide (Bi2O3) has been obtained between 26° and 778°C by the Rietveld method using neutron powder diffraction data. Lattice parameters 〈inlineGraphic alt="inline image" href="urn:x-wiley:00027820:JACE00432:JACE_00432_mu4" location="equation/JACE_00432_mu4.gif"/〉 and unit-cell volume of α and δ phases increased, while the β angle of α phase decreased with an increase of temperature. Here the 〈inlineGraphic alt="inline image" href="urn:x-wiley:00027820:JACE00432:JACE_00432_mu5" location="equation/JACE_00432_mu5.gif"/〉 denotes the lattice parameter a of the α phase on the basis of pseudo-fluorite lattice. The thermal expansion coefficients of α phase were 26.7, 6.6, and 9.0 (× 10−6°C−1) for 〈inlineGraphic alt="inline image" href="urn:x-wiley:00027820:JACE00432:JACE_00432_mu6" location="equation/JACE_00432_mu6.gif"/〉 and 〈inlineGraphic alt="inline image" href="urn:x-wiley:00027820:JACE00432:JACE_00432_mu7" location="equation/JACE_00432_mu7.gif"/〉 axes, respectively, indicating a large anisotropy. The α- to -δ phase transition of Bi2O3 was confirmed between 721° and 760°C on heating. At the α–δ transition point, the lattice parameters and unit-cell volume discontinuously changed, indicating that the transition is of the first order.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1551-2916.2005.00432.x
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