TY - JOUR
T1 - Effect of phase separation on the properties of simple glasses I. Density and molar volume
AU - Shaw, R. R.
AU - Uhlmann, D. R.
N1 - Funding Information:
The M.I.T. part of this work was supported by the U.S. Atomic Energy Commission under Contract AT(30-1)2574. R. Grafprepared the lead borate glasses used in this work. J. F. Breedis and D. Guernsey of M.I.T. provided electron microscopy and chemical analyses, respectively.
PY - 1969/11
Y1 - 1969/11
N2 - The variation of bulk density with composition across a miscibility gap is adequately described by a simple model in which volume additivity of the two phases is assumed. The density-weight percent composition function must always have positive (concave-upward) curvature across a two-phase region. The density-mole percent composition function can have either positive or negative curvature, depending upon the location of the miscibility gap in the binary diagram and upon the molecular weights of the end-member oxides. Immiscible composition regions are generally signalled more clearly by simple density-weight percent composition plots than by density-mole percent plots or molar volume or partial molar volume analyses. The model is used to predict possible immiscible regions in the system K2OSiO2, PbOSiO2, B2O3GeO2, SiO2GeO2, PbOGeO2, and PbOP2O5. Immiscibility is probably not present on the GeO2-rich side of the alkali germanate series of glasses. The LiF-rich limit of the miscibility gap in the LiF-BeF2 system is estimated.
AB - The variation of bulk density with composition across a miscibility gap is adequately described by a simple model in which volume additivity of the two phases is assumed. The density-weight percent composition function must always have positive (concave-upward) curvature across a two-phase region. The density-mole percent composition function can have either positive or negative curvature, depending upon the location of the miscibility gap in the binary diagram and upon the molecular weights of the end-member oxides. Immiscible composition regions are generally signalled more clearly by simple density-weight percent composition plots than by density-mole percent plots or molar volume or partial molar volume analyses. The model is used to predict possible immiscible regions in the system K2OSiO2, PbOSiO2, B2O3GeO2, SiO2GeO2, PbOGeO2, and PbOP2O5. Immiscibility is probably not present on the GeO2-rich side of the alkali germanate series of glasses. The LiF-rich limit of the miscibility gap in the LiF-BeF2 system is estimated.
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U2 - 10.1016/0022-3093(69)90009-X
DO - 10.1016/0022-3093(69)90009-X
M3 - Article
AN - SCOPUS:0000025204
SN - 0022-3093
VL - 1
SP - 474
EP - 498
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
IS - 6
ER -