The System CaO‐Ga 2 O 3

CaO and Ga 2 O 3 form three compounds: 3CaO‐Ga 2 O 3 , CaO‐Ga 2 O 3 , and CaO‐2Ga 2 O 3 . 3CaO‐Ga 2 O 3 melts incongruently to CaO plus liquid at 1263°C.; CaO Ga 2 O 3 and CaO 2Ga 2 O 3 melt congruently at 1369° and 1504°C. respectively. Eutectics are located at the following temperatures and compositions (in mole% Ga 2 O 3 ): between 3CaO Ga 2 O 3 and CaO Ga 2 O 3 , 1245°C. and 37.5%; between CaO Ga 2 O 3 and CaO‐2Ga 2 O 3 ,1323 o C. and 57.0%; and between CaO ‐2Ga 2 O 3 and β‐Ga 2 O 3 ,1457°C. and 68.0%. There is a peritectic at 1263°C. and 36.0%. Three polymorphs of CaO Ga 2 O 3 are described. Compositions from approximately 35 to 70 mole% Ga 2 O 3 can be quenched to yield homogeneous glasses.