Americium

Americium, element 95, was discovered in 1944–45 by Seaborg et al. (1950) at the Metallurgical Laboratory of the University of Chicago as a product of the irradiation of plutonium with neutrons:

²³⁹Pu(n,γ)²⁴⁰Pu(n,γ)²⁴¹Pu → ²⁴¹Am

This reaction is still the best method for the production of pure ²⁴¹Am. In post-World War II work at the University of Chicago, Cunningham isolated Am(OH)₃ and measured the first absorption spectrum of the Am³⁺ aquo ion (Cunningham, 1948). By the 1950s, the major center for americium chemistry research in the world was at Los Alamos. Since the 1970s, the majority of publications on americium have come from researchers in the former USSR and West Germany. Extensive reviews of americium chemistry can be found in Freeman and Keller (1985), Gmelin (1979), Penneman and Asprey (1955), and Schulz (1976).