NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PUBLICATIONS

Crystal Structure of the Type I Clathrate Ba8Ni4Ge42

Published

Author(s)

Winnie K. Wong-Ng, Qingzhen Huang, Igor Levin, Joseph C. Woicik, Xun Shi, Jihui Yang, James A. Kaduk

Abstract

The crystal structure of Type-I clathrate Ba8Ni4Ge42 has been determined using neutron powder diffraction, transmission electron microscopy (TEM, for possible superlattice), extended X-ray absorption fine structure measurements. Ba8Ni4Ge42 is cubic with the space group Pm-3n and lattice parameter a=10.6769(2) Å (Dx=5.988 g.cm-3). The structure combines two different types of polyhedra: the dodecahedtron (Ge20, 10 pentagonal faces) and the tetrakeidecahedron (Ge24, 12 pentagonal and 2 hexagonal faces). The unit cell contains two Ge20 dodecahedra and six Ge24 tetrakaidecahedra . The Ge20 dodecahedra are linked via the interstitial 6c positions. The framework structure is formed by a tetrahedrally bounded network of Ge whereas Ba atoms reside inside the Ge20 and Ge24 cavities at the 2a and 6d crystallographic positions, respectively. Ni atoms occupy exclusively the 6c positions located on the hexagonal faces of the larger tetrakaidecahedra; no Ni was found in the smaller dodecahedra which consist of pentagonal faces. Electron diffraction in TEM revealed no detectable Ge/Ni ordering.
Citation
Journal of Solid State Chemistry
Volume
27
Pub Type
Journals

Download Paper

DOI Link

Keywords

Type-I clathrate, Ba8Ni4Ge42, crystal structure, neutron diffraction, TEM, synchrotron EXAFS
Materials

Citation

Wong-Ng, W. , Huang, Q. , Levin, I. , Woicik, J. , Shi, X. , Yang, J. and Kaduk, J. (2012), Crystal Structure of the Type I Clathrate Ba8Ni4Ge42, Journal of Solid State Chemistry, [online], https://doi.org/10.1017/S0885715612000024 (Accessed October 18, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created March 30, 2012, Updated November 10, 2018
Was this page helpful?