In the ternary La2O3-TiO2-ZrO2 system the subsolidus phase relations at 135
0 degrees C were determined using X-ray diffraction, scanning electron micr
oscopy end energy dispersive X-ray analysis. The collected results are pres
ented in the form of a phase diagram. In the equilibrium state there are 7
ternary and 5 binary compatible subsystems. In the system TiO(2)ss, ZrO(2)s
s, ZrTiO(4)ss, La(2)Zr(2)O(7)ss and La(2)O(3)ss solid solutions were confir
med and La(4)Ti(9)O(24)ss and La(2)Ti(2)O(7)ss solid solutions were identif
ied. The addition of ZrO2 does not stabilize the La2/3TiO3 perovskite compo
und, nor the addition of TiO2 a highly temperature stable compound La2/3ZrO
3.