抄録
The viscosities of MeO (MeO=Li2O, Na2O, CaO, SrO)-SiO2-Y2O3 silicate melts were measured in order to investigate the behaviour of Y2O3 in the silicates. The results indicate that Y2O3 plays a role as an amphoteric oxide as Al2O3 in the silicate melts and the viscosities measured in this study were well arranged using the following parameter (Pη) which was introduced in the ternary silicate systems containing Al2O3 or Ga2O3 to explain the amphoteric behaviour of those oxides in the silicates.
The parameter Pη is expressed by
(This article is not displayable. Please see full text pdf.)
\
oindentwhere ZMe is the electric charge of Me ion, ni is the ion fraction of i ion and XY is the ratio of tetrahedrally coordinated Y3+ ions to total Y3+ ions.
The XY values of Li2O, Na2O, CaO and SrO systems were calculated to be 0.32, 0.45, 0.36 and 0.41, respectively. Since these values showed about half of those XAl in the same silicate systems, it was clarified that Y2O3 was more basic than Al2O3.
