Synthesis and Structure of a New Zeolite-Like Framework Phase in the Na-Ge System: Na1-xGe3+z

Published

October 12, 2021

Author(s)

Matthew Beekman, James A. Kaduk, Qingzhen Huang, Winnie Wong-Ng, Zhi Yang, Dongli Wang, George S. Nolas

Abstract

During an attempt to synthesize NaGe136 (a Type-II clathrate) using a vacuum decomposition technique, a novel Na-Ge phase was obtained instead. The framework of this new phase was determined using the combined results of synchrotron, neutron, and laboratory x-ray diffraction experiments on two Na-Ge samples that were prepared with a somewhat different procedure. The structure is hexagonal with the P6/m space group and with Z=8. The lattice parameters were determined by x-ray diffraction to be: a=15.05399(5) , c=3.968450(15) (Sample I). This new structure is of the open-channel zeolite-type and its framework is built from covalently bonded Ge. There are two channels of different sizes running along the c-axis. While both channels are of a hexagonal shape, the smaller one consists of one Na per channel (two channels per unit cell). In the broad channel (one per unit cell), a maximum of 6 Na s are found. The content of Na varies depending on the processing conditions. The chemical formula of the new Na-Ge phase can be written as Na1-xGe3+z, indicating the structure can accommodate a range of different concentration of Na and Ge.

Citation

Journal of the American Chemical Society Communication

Pub Type

Journals

Keywords

crystal structure, Nal-zGe3+z, type-II clathrate related, Zeolite-like framework phase

Citation

Beekman, M. , Kaduk, J. , Huang, Q. , Wong-Ng, W. , Yang, Z. , Wang, D. and Nolas, G. (2021), Synthesis and Structure of a New Zeolite-Like Framework Phase in the Na-Ge System: Na_1-xGe_3+z, Journal of the American Chemical Society Communication (Accessed April 24, 2024)