A SHORT-RANGE ORDER STRUCTURAL INVESTIGATION OF AMORPHOUS EUROPIUM, GADOLINIUM, AND TERBIUM HYDROUS OXIDES

The amorphous lanthanide hydrous oxides are structurally related to la nthanide oxyhydroxides and trihydroxides. The bulk short-range orders (SROs) of amorphous europium, gadolinium, and terbium hydrous oxides a re the subject of this work. The instrumental arrangement, data collec tion, and data reduction are discussed. The scattering profiles are pr esented as well as the calculated interference functions, S(i)(S). SRO information was derived from calculated radial distribution functions (RDFs). The central metal atoms are nine-coordinated and the mean M-O bond distances where M = Eu, Gd, and Th are 2.46 (1), 2.44 (3), and 2 .41 (1) angstrom, respectively. Comparisons of experimentally obtained RDF curves to those calculated from crystalline systems were performe d to lend credence to the experimental results.