Curium(IV) oxide

Curium(IV) oxide is an inorganic chemical compound of curium and oxygen with the chemical formula CmO2. Since all isotopes of curium are man-made, the compound does not occur in nature.

Synthesis

 * Curium(IV) oxide can be prepared directly from the elements. Metallic curium is annealed in air or in an oxygen atmosphere:


 * Cm + O2 -> CmO2


 * Curium(III) hydroxide and curium(III) oxalate are also usually used for this purpose:


 * Cm(OH)4 -> CmO2 + 2H2O


 * Cm(C2O4)2 -> CmO2 + 2CO2 + 2CO


 * Another way is the reaction of curium(III) oxide in an oxygen atmosphere at 650 °C:


 * 2Cm2O3 + O2 -> 4CmO2

Physical properties
Curium(IV) oxide forms black crystals. Insoluble in water. The compound crystals are of the cubic crystal system, the fluorite structure in the space group Fm3m.

Chemical properties
The compound reacts with mineral acids to form solutions of curium(III) salts.

Uses
The compound is used for the manufacturing of isotopic current sources, also as targets for the synthesis of transcurium elements.