Density measurements of molten Y3Al5O12 and Y2O3‐Al2O3 compounds using an electrostatic levitation technique.

The densities of molten Y2O3‐Al2O3 compounds, including yttrium aluminum garnet (Y3Al5O12), were determined over a wide temperature range that included an undercooled region, using an electrostatic levitation furnace. The density of the molten Y3Al5O12 varied with temperature according to the relationship 3750 − 0.25(T − Tm) (kg/m3) with Tm = 2240 K and for the range of 1300 K ≤ T ≤ Tm, yielding the thermal expansion coefficient ɑ = 6.7×10−5 K−1. The molar volumes of molten (100‐x)Y2O3‐xAl2O3 (x = 0, 33.3, 50, 55, 62.5, 76.5, 81.5, or 100 mol%) were found to vary with the value of x in a linear manner within the superheated temperature range. However, the molar volumes in the undercooled region deviated from those calculated using an ideal solution model owing to attractive interactions between Y2O3 and Al2O3. [ABSTRACT FROM AUTHOR]