Crystal chemistry of the G-phases in the {Ti, Zr, Hf}-Ni-Si systems
- Author(s)
- Andrij Grytsiv, Xingqiu Chen, Peter Franz Rogl, Raimund Podloucky, Harald Schmidt, Gerald Giester, Vladimir Pomjakushin
- Abstract
Ternary compounds M 6Ni16Si7 (M =Ti, Zr, Hf) have been investigated by X-ray powder/single crystal and neutron powder diffraction. Compounds with Zr and Hf crystallize in the ordered Th6Mn23 type (Mg6Cu16Si7-type, space group Fm3¯m), whereas Ti6Ni16.7Si7 contains an additional Ni atom partially occupying the 24e site (M2 site, x=0.4637,0,0; occ.=0.119) inside a Ti octahedron; Ti atoms occupy a split position. Ti6Ni16.7Si7 represents a new variant of the filled Th6Mn23 type structure. Ab initio calculations confirm the structural difference: additional Ni atoms favour the 24e site for Ti6Ni16.7Si7, however, for the Zr and Hf-based compounds the unoccupied site renders an energetically lower ground state. Enthalpies of formation of Ti6Ni17Si7, Zr6Ni16Si7, and Hf6Ni16Si7 were calculated to be −68.65, −74.78, and −78.59 kJ/(mol of atoms), respectively.. © 2006 Elsevier Inc. All rights reserved.
- Organisation(s)
- Department of Physical Chemistry, Department of Mineralogy and Crystallography
- External organisation(s)
- Eidgenössische Technische Hochschule Zürich
- Journal
- Journal of Solid State Chemistry
- Volume
- 180
- Pages
- 733-741
- No. of pages
- 9
- ISSN
- 0022-4596
- DOI
- https://doi.org/10.1016/j.jssc.2006.11.031
- Publication date
- 2007
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105113 Crystallography
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/ae6445c6-4717-4e43-82fe-73dd0c2437c0