Photo: rare-earth oxides clockwise from top center: praseodymium, cerium, lanthanum, neodymium, samarium, and gadolinium. Photo credit: Peggy Greb, US Department...
Photo: rare-earth oxides clockwise from top center: praseodymium, cerium, lanthanum, neodymium, samarium, and gadolinium. Photo credit: Peggy Greb, US Department...