Density and Expansivity of Alkali Borates and Density Characteristics of Some Other Binary Glasses

Abstract

The densities of liquids in the systems LizOBz03, Na20-B20,, and Kz0-Bz03 were measured by a counterbalanced-sphere method over the approximate temperature range 600" to 1000°C.The room-temperature densities of alkali borate glasses were also measured. Density increased with increasing percentages of alkali oxide below 30 mole yo. At high temperatures the densitycomposition curves showed maxima at about 30 mole yo alkali oxide. Expansivities over various temperature ranges were calculated from change of density with temperature. Expansivities in the liquid range increased with alkali content.In the low-alkali region, expansivity in the liquid range decreased with rising temperature whereas contrary behavior was noted in the high-alkali region. The most striking effect caused by the addition of alkali to Bz03 was a volume contraction. Some reasons were found to account for the lack of agreement with experimental observations of the methods of Huggins and Stevels for calculating densities.

Densities of Li2O–B2O3 melts

“…Earlier published data [7,8,10,11,13] are also shown in the same figure for comparison. It can be seen that the densities obtained in this work agreed well with each other for those measured during the cooling and heating processes.…”

“…The present results are systematically higher than those of Refs. [7,8,13], where density was measured by a counterbalanced sphere and an Archimedean double-bob method, respectively. For pure B 2 O 3 melt, a linear increase of density with increasing temperature was reported [13], as shown in Fig.…”

“…For a potential application and scientific interest, it is, therefore, very necessary to measure the physical properties of this system. Experimental study of the densities of xLi 2 O-(1Àx)B 2 O 3 melts had been earlier performed around the 1970s [7][8][9][10][11]. However, most published density data of xLi 2 O-(1Àx)B 2 O 3 melts showed a large discrepancy in different authors' results [7][8][9][10][11][12][13].…”

Interatomic Potential Model for Molecular Dynamics Simulation of Lithium Borate Melts/Glasses

“…The densities of glasses at several temperatures are shown in Figure 8. The densities of simulated glasses by ia2 potential model are near to the experimental data [18,19], but it is not acceptable because this density must be brought by the abnormal dense structure units. The densities of ia3 simulations are lower than the experimental, especially for small x compositions.…”

“…we already started discussion and improving of the partial ionic charge model applied in this work [20]. Squares are the reference data at 298 K [18] and 1129 K [19].…”