Californium(III) oxide

Californium(III) oxide is a binary inorganic compound of californium and oxygen with the formula. It is one of the first obtained solid compounds of californium, synthesized in 1958.

Synthesis
The compound can be prepared by burning ionite in air, on which ions of trivalent californium are sorbed, at a temperature of 1400 °C. It can also be obtained by β-decay of berkelium(III) oxide.

Physical properties
Californium(III) oxide forms a yellow-green solid with a melting point of 1750 °C and exists in three modifications. The body-centered cubic modification forms a crystal lattice with a = 1083.9 ± 0.4 pm. The transition temperature between body-centered cubic and monoclinic structures is about 1400 °C.

It is insoluble in water.