Structure of Proton-Conducting Alkali Thio-Hydroxogermanates
Artikel i vetenskaplig tidskrift, 2008

Using a combination of neutron diffraction, infrared spectroscopy, and first-principles calculations, we have investigated the structure of hydrated and dehydrated proton conducting alkali thio-hydroxogermanates of general formula M2GeS2(OH)2·yH2O (M = K, Rb, and Cs). The results show that the structure of hydrated and dry materials are basically the same, which confirms previous indications that the main effect of heating these materials is just a loss of water. We suggest that in the hydrated state the structure of these materials is built of dimers of thio-hydroxogermanate anions, with the water molecules acting as bridges between such dimers. In the dehydrated structure, the thio-hydroxogermanate anions instead form an extended network through the formation of interdimer hydrogen bonds through the −OH groups in the structure. The alkali ions are suggested to act as “space-fillers” in voids formed by the thio-hydroxogermanate anion dimers, in both the hydrated and the dehydrated state.

temperature

infrared-spectroscopy

density

spectra

oxide fuel-cells

Författare

Maths Karlsson

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Aleksandar Matic

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Itai Panas

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

D.T. Bowron

ISIS Facility

Steve Martin

Iowa State University

C.R. Nelson

Iowa State University

C.A. Martindale

Iowa State University

Andreas Hall

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Lars Börjesson

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Chemistry of Materials

0897-4756 (ISSN) 1520-5002 (eISSN)

Vol. 20 6014-6021

Ämneskategorier

Materialteknik

Fysikalisk kemi

Teoretisk kemi

Den kondenserade materiens fysik

DOI

10.1021/cm8006155