Americium(III) oxide or americium sesquioxide is an

oxide An oxide () is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– (molecular) ion. with oxygen in the oxidation state of −2. Most of the E ...

of the element

americium Americium is a synthetic radioactive chemical element with the symbol Am and atomic number 95. It is a transuranic member of the actinide series, in the periodic table located under the lanthanide element europium, and thus by analogy was na ...

. It has the empirical formula Am₂O₃. Since all

isotopes of americium Americium (95Am) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no known stable isotopes. The first isotope to be synthesized was 241Am in 1944. The artificial element decays b ...

are only artificially produced, americium (III) oxide has no natural occurrence. The colour depends on the crystal structure, of which there are more than one. It is soluble in acids.

Formation

Americium(III) oxide can be made by heating

americium dioxide Americium is a synthetic radioactive chemical element with the symbol Am and atomic number 95. It is a transuranic member of the actinide series, in the periodic table located under the lanthanide element europium, and thus by analogy was na ...

in hydrogen at 600°C. :2 AmO2 + H2 -> Am2O3 + H2O

Forms

The hexagonal form is coloured tan, and the cubic form is coloured red-brown the same as

persimmon The persimmon is the edible fruit of a number of species of trees in the genus ''Diospyros''. The most widely cultivated of these is the Oriental persimmon, ''Diospyros kaki'' ''Diospyros'' is in the family Ebenaceae, and a number of non-pers ...

. The cubic form converts to the hexagonal form on heating to 800°C. The cubic form is non-stoichimetric with variable oxygen composition. It darkens with increasing oxygen.

References

{{Oxides Americium compounds Sesquioxides