Abstract
A thermogravimetric study was made of the reaction of the zirconia stabilizing oxides, 
, 
, 
, and 
, with molten 
at 800°C under 
partial pressures of 10+2 to 10−3 Pa. The melt composition is determined by:
. No reaction of 
was found at 
partial pressures up to 
where the reaction,
, commenced. Reaction of 
occurred at about 
of 
, with 
formed. Reaction of 
and 
with the 
melt began, on the other hand, at 
partial pressures too low to be measured (<10−3 Pa).
and 
are thus potentially superior to 
and 
as stabilizers for hot corrosion resistant zirconia thermal barrier coatings. Certain other information concerning the thermochemistry of the 
system was also revealed.