title: Local structure of Ge nanocrystals embedded in SiO2 studied by X-ray absorption fine structure.
abstract: Local structure of Ge nanocrystals embedded in SiO2 has been studied by X-ray absorption fine structure on the Ge K-edge. The XANES and EXAFS results indicate that Ge atoms in samples with the Ge concentration x=25-40 mol. % are coordinated with oxygen atoms, while they exist as amorphous Ge clusters in samples with x=60 mol. %. Upon annealing, completely relaxed crystalline Ge phase is formed for samples with x=60 mol. %, in contrast to the x=25-40 mol. % sample, which show little or no indication of Ge cluster formation. A possible mechanism of Ge nanocluster formation is discussed.
authors.affiliation: Joint Research Center for Atom Technology-National Institute for Advanced Interdisciplinary Research, Tsukuba, Ibaraki, Japan.
authors.forename: A V
authors.initials: AV
authors.lastname: Kolobov
authors.forename: H
authors.initials: H
authors.lastname: Oyanagi
authors.forename: Y
authors.initials: Y
authors.lastname: Maeda
authors.forename: K
authors.initials: K
authors.lastname: Tanaka