The preparation and electrical conductivity of

-

are investigated as a function of

content from the-oretical composition of

-

to that of

"-

.

-

"


-Al2O3 and

-NaAlO2 phases appear in the calcined powder at 125

for 2 hours. The majoity phase is

-

in sintered specimens at 155

and 1

for 30 mins respectively and

-

phase also exists when Na2O content is over 10.39w/o

-

phase does not affect the grain growth of

-

in sintering at 155

but acts as a reactive liquid for the abnormal grain growth of

-

in sintering at 1

The electrical conduction of

-

is predominated by

ion. Contribution of ionic con-ductivity to total conductivity is gradually decreased with increasing temperature at given oxygen pressure and to -tal conductivity is increased by positive hole due to interstitial oxygen with increasing oxygen pressure.