부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jssc.2008.04.034 Byline: Karin Soderberg (a), Yoshiki Kubota (b), Norihiro Muroyama (a), Daniel Gruner (a), Arisa Yoshimura (b), Osamu Terasaki (a) Keywords: Intermetallic compounds; Laves phases; Charge density; Maximum entropy method Abstract: Using short wavelength X-rays from synchrotron radiation (SPring-8), high-resolution powder diffraction patterns were collected. In order to study both the structural relationship and the mechanism of stability in the CaAl.sub.2- .sub.x Zn.sub.x system, among the Laves phases (MgCu.sub.2 and MgNi.sub.2 type) and KHg.sub.2-type structures, the charge density distribution of CaAl.sub.2- .sub.x Zn.sub.x as a function of x was obtained from the diffraction data by Rietveld analysis combined with the maximum entropy method (MEM). In the MEM charge density maps overlapping electron densities were clearly observed, especially in the Kagome nets of the Laves phases. In order to clarify the charge redistribution in the system, the deformation charge densities from the densities formed by the constituent free atoms are discussed. In the ternary MgNi.sub.2-type phase, partial ordering of Al and Zn atoms is observed, a finding that is supported by ab-initio total energy calculations. Author Affiliation: (a) Arrhenius Laboratory, Department of Physical, Inorganic and Structural Chemistry, Stockholm University, Stockholm 10691, Sweden (b) Graduate School of Science, Department of Physical Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan Article History: Received 19 December 2007; Revised 11 April 2008; Accepted 24 April 2008