Surface Tensions and Densities of Molten Al2O3, Ti2O3, V2O5 and Nb2O5.

Abstract

Surface tensions and densities of molten Al203' Ti203' V205and Nb205 were determined accurate[y by the maximum bubble pressure method. The measurementswere carried out under Ar+ I Oo/oH2for molten Al203 and Ti203' and under air for molten V205and Nb205' Surface tension and density of molten Al203 near the melting point are 606 ~6mN m I and 3,06 ~0.03 x I 03 kg m ~3, and those of molten Ti203 are 584 ~5mN m~1 and 3.91 :~0.03 > I 03 kg m~3, respectively. The temperature coefficient of surface tension of molten V205 is slightly positive value of 0.0111 mNm~1 K-1, while for molten Nb205 it is negative value of -0.0596 mN m1 K-1. This suggests that the network structure of molten V205 changes with temperature. The temperature coefficient of density of molten V205 is very low. The results are discussed in comparison with those of other molten pure oxides and fluorides having high melting points.