In search for chemically stable americium compounds with
high power
densities for radioisotope sources for space applications, AmVO3and AmVO4were prepared by a solid-state reaction.
We present here their crystal structure at room temperature solved
by powder X-ray diffraction combined with Rietveld refinement. Their
thermal and self-irradiation stabilities have been studied. The oxidation
states of americium were confirmed by the Am M5edge high-resolution
X-ray absorption near-edge structure (HR-XANES) technique. Such ceramics
are investigated as potential power sources for space applications
like radioisotope thermoelectric generators, and they have to endure
extreme conditions including vacuum, high or low temperatures, and
internal irradiation. Thus, their stability under self-irradiation
and heat treatment in inert and oxidizing atmospheres was tested and
discussed relative to other compounds with a high content of americium.