Sintering optimization and microscopic alteration mechanism of americium oxide analogues for space energy power

Radioisotope thermoelectric generators (RTGs) produce electrical energy exclusively through the natural decay of radioactive materials, rendering them an ideal power source for space missions and other extreme environments. 241 Am is viewed as a promising substitute for 238 Pu as the heat-generating nuclide in these applications. However, there is currently no consensus on the sintering of 241 Am (Ⅲ) pellets. In this research, Nd (Ⅲ) oxide was used as a surrogate for americium (Ⅲ) oxide, and conventional cold-press-and-sinter methods were employed. Through a systematic investigation of the heating rate, holding time, and maximum temperature during the sintering of Nd (Ⅲ) oxide pellets made from commercial materials, an optimized sintering thermal cycle was developed. This curve enhances sintering efficiency and results in pellets with an open pore network, which is crucial for helium gas release. This work is significant in advancing the research and development of 241 Am nuclear batteries.