Dingwell, Donald B.
Shear viscosity of alkali and alkaline earth titanium silicate liquids.
In: American Mineralogist, Vol. 77, No. 3-4: pp. 270-274
The shear viscosities of l3 silicate liquids along the NarSiOr-TiO, and CaSiOr-TiO, joins as well as six liquids based on the sphene stoichiometry X#TiSiO. (where X represents Li, Na, K, Rb, Cs, Ca, and Sr) have been measured in equilibrium with air using the concentric cylinder method. The NarSiOr-TiO, join was investigated from l0 to 50 mol0/oT iO, in the temperaturer ange 1000-1150 "C, whereast he CaSiO3-TiO,jo in was investigated from l0 to 80 molo/oT iO, in the temperature range of 1400-1625' C. The shear viscosities of liquids in the CaSiOr-TiO, and NarSiOr-TiO2 systems decrease with the addition of TiO,. The decreaseis linear in the CaSiOr-TiO, system at 1400- I 600 'C but nonlinear in the NarSiO3-TiO, system at 1000-1 150'C. Viscosities of melts of sphene stoichiometry, X1;TiSiO, (where X: Cs, Rb, K, Na, Li, Ba, Sr, and Ca), decrease with increasing field strength. Similar to the behavior of ferro-, alumino-, and galliosilicate
melts, this decreaseis strong for the alkalies but very weak for the alkaline earths.