Search: onr:"swepub:oai:research.chalmers.se:7a91bc0d-721c-44c4-950c-caefedd0dcd3" >
Alkali-ion concentr...
Alkali-ion concentration dependence of the structure of proton-conducting alkali thio-hydroxogermanates investigated with neutron diffraction
-
- Karlsson, Maths, 1978 (author)
- Chalmers tekniska högskola,Chalmers University of Technology
-
- Nordström, Jonas, 1980 (author)
- Chalmers tekniska högskola,Chalmers University of Technology
-
- Matic, Aleksandar, 1968 (author)
- Chalmers tekniska högskola,Chalmers University of Technology
-
show more...
-
- Martin, Steve (author)
- Iowa State University
-
- Imberti, S. (author)
- STFC Rutherford Appleton Laboratory
-
- Bowron, D.T. (author)
- STFC Rutherford Appleton Laboratory
-
show less...
-
(creator_code:org_t)
- Elsevier BV, 2015
- 2015
- English.
-
In: Solid State Ionics. - : Elsevier BV. - 0167-2738. ; 274, s. 40-45
- Related links:
-
http://dx.doi.org/10...
-
show more...
-
http://manuscript.el...
-
https://doi.org/10.1...
-
https://research.cha...
-
show less...
Abstract
Subject headings
Close
- The proton-conducting hydrated alkali thio-hydroxogermanate's MxGeSx(OH)(4) - x center dot yH(2)O (M = Na and K; x = 1 - 4,y approximate to 0.5 - 2) were investigated by means of neutron diffraction with the aim to elucidate how the structure changes as a function of alkali-ion concentration, x, type of alkali ion, M, and water content, y. For x = 1 - 3 we find that the materials are amorphous and composed of thio-hydroxogermanate anions, water molecules, and charge balancing alkali ions, whereas for x = 4 we find that the materials contain also a crystalline phase, suggesting that it is difficult to prepare purely amorphous materials for the highest alkali-ion concentration, for both the Na and K based materials. For x = 1 - 3, the structure is reflected by an intermediate-range ordering, with a characteristic length-scale ranging from approximately 6 to 9 angstrom, which is dependent on both x and M and which may be related to the separation distance between dimers of thio-hydroxogermanate anions. As x increases, the intermediate-range ordering shortens, possibly as the result of an increasing level of hydration water that may act as a dielectric medium that reduces the repulsive interaction between the negatively charged thio-hydroxogermanate anions and/or between the positively charged alkali ions. A comparison of the structural results to the reported conductivities of the same materials indicates a non-trivial relationship, which depends on both the type and concentration of alkali ions, as well as on the level of hydration water.
Subject headings
- NATURVETENSKAP -- Kemi -- Fysikalisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Physical Chemistry (hsv//eng)
Keyword
- Proton conducting
- Thio-hydroxogermanate
- Fuel cell
- Neutron diffraction
Publication and Content Type
- art (subject category)
- ref (subject category)
Find in a library
To the university's database