Le diagramme des phases solides du systeme Bi2O3CaO

The phase diagram Bi 2 O 3 CaO has been investigated in the solid state by high temperature X-ray analysis and D.T.A. methods. Four compounds (Bi 14 Ca 5 O 26 , Bi 2 CaO 4 , Bi 10 Ca 7 O 22 , and Bi 6 Ca 7 O 16 ), which melt incongruently, and four solid solutions (fcc, bcc, and two rhombohedral) have been characterized. Quenchings of the fcc solid solution lead to several metastable fluorite-type ss. These, as well as the quenched forms of the rhombohedral and bcc solid solutions, have defect oxygen lattice consistent with the formula Bi (2−2 n ) Ca (2 n −1) O (2− n ) □ n .