title: Site preference and lattice relaxation around 4d and 5d refractory elements in Ni3Al.
abstract: X-ray absorption spectroscopy is employed to investigate site preference and lattice relaxation around Mo, Ru, Hf, W and Re dopants in Ni3Al. The site occupation preference and the measured distances between the refractory elements as dopants and the nearest host atoms are compared with the results of ab initio calculations within the density functional theory. Combined experimental and theoretical results indicate that Mo, Hf, W and Re atoms reside on the Al sublattice in Ni3Al, while Ru atoms occupy the Ni sublattice. A more pronounced lattice relaxation was detected in the case of Hf and Ru doping, with a strong outward relaxation of the nearest Ni and Al atoms.
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, Belgrade 11001, Serbia.
authors.forename: Ana
authors.initials: A
authors.lastname: Umićević
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.
authors.forename: Heinz-Eberhard
authors.initials: HE
authors.lastname: Mahnke
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, Belgrade 11001, Serbia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Belošević-Čavor
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, Belgrade 11001, Serbia.
authors.forename: Božidar
authors.initials: B
authors.lastname: Cekić
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schumacher
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, Belgrade 11001, Serbia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Madjarevic
authors.affiliation: Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, Belgrade 11001, Serbia.
authors.forename: Vasil
authors.initials: V
authors.lastname: Koteski
keywords: ab initio calculations; extended X-ray absorption fine structure (EXAFS); nickel superalloys; site preference