Phase Relations in the System Bi₂O₃‐WO₃

Abstract

I Ultra-low Expansion Gloss V-AK"; 60°c I . o 10.0 Fig. 8. Proof-test diagram for (A) data for ultralow-expansion glass collected at 60°C, represented by power function, v =AK,", and (B) data for fused S O , represented by exponential function. Numbers on curves are proof-test ratios, UJU,.Service Stress, 0,. MN/rn2 Service Stress, q , MN/m2 essential that the functional dependence of stress intensity factor on crack velocity be known; otherwise, large differences in predicted lifetime can occur. For Space-Shuttle applications, the extrapolation does not result in excessive errors in lifetime prediction. The glass studied in the work was of the anomalous type in fracture behavior and similar to other high-SiO, glasses.

The crystal structure of russellite; a re-determination using neutron powder diffraction of synthetic Bi2WO6

“…Further work on this system by Hoda and Chang (1974) agreed with the crystal system determination of Gal'perin etal. but no diffraction data were included in their paper.…”

“…) found their single crystal grown by flux methods had the composition Bi2W209 and gave the identical diffraction pattern to russellite. On this basis, they proposed that a solid solution existed between Bi2WO 6 and BisW209, although this has subsequently been challenged by the recent phase diagram determination of Hoda and Chang (1974) who found Bi2WO6 to be a line phase. However, considering the limited resolution of 6 cm powder cameras, the difficulty of distinguishing between Bi 3+ and W 6 § in highly pseudo-symmetric positions, and the tendency of these compounds to show integral axial ratios, it is probable that Hey and Bannister would have been unable to fully characterise any of these compounds.…”

Subsolidus phase relations in the ZnO–WO3–Bi2O3 system

“…Our result is in good agreement with Ref. [28]. Bi 2 W 2 O 9 belongs to orthorhombic system with space group Pbn2 1 .…”

“…Although several investigations of the system have been conducted, the results were different from each other [23][24][25][26][27][28]. A latest whole phase diagram of Bi 2 O 3 -WO 3 system was reported by Hoda and Chang [28] high-temperature face-centered cubic form.…”

“…Although several investigations of the system have been conducted, the results were different from each other [23][24][25][26][27][28]. A latest whole phase diagram of Bi 2 O 3 -WO 3 system was reported by Hoda and Chang [28] high-temperature face-centered cubic form. Meanwhile, their relationships were shown: the reversible monoclinic-to-orthorhombic transition at about 40 • C was displacive, while a reconstructive order-disorder transition occurred reversibly at 780 • C from the orthorhombic form to the face-centered cubic form.…”