Figure 1. Bi₂O₃ rich regions of Bi₂O₃–R₂O systems, as determined from high-temperature x-ray diffraction data.

Phases: Mon—monoclinic, C—cubic, ?—unknown, Liq—liquid

(A) Bi₂O₃–Li₂O

a—Trace of unknown phase observed.

(B) Bi₂O₃–Rb₂O

a—No second phase seen,

b—Rb₂O apparently volatilizes from liquid,

c—Liquid cools to b.c.c. phase: a=10.22A.