Change search
ReferencesLink to record
Permanent link

Direct link
Dynamics of Pyramidal SiH3- Ions in ASiH(3) (A = K and Rb) Investigated with Quasielastic Neutron Scattering
Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
Show others and affiliations
Number of Authors: 6
2016 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 120, no 12, 6369-6376 p.Article in journal (Refereed) Published
Abstract [en]

The two alkali silanides ASiH(3) (A = K and Rb) were investigated by means of quasielastic neutron scattering, both below and above the order-disorder phase transition occurring at around 275-300 K. Measurements upon heating show that there is a large change in the dynamics on going through the phase transition, whereas measurements upon cooling reveal a strong hysteresis due to undercooling of the disordered phase. The results show that the dynamics is associated with rotational diffusion of SiH3- anions, adequately modeled by H-jumps among 24 different jump locations radially distributed around the Si atom. The average relaxation time between successive jumps is of the order of subpicoseconds and exhibits a weak temperature dependence with a small difference in activation energy between the two materials, 39(1) meV for KSiH3 and 33(1) meV for RbSiH3. The pronounced SiH3- dynamics explains the high entropy observed in the disordered phase resulting in the low entropy variation for hydrogen absorption/desorption and hence the origin of these materials' favorable hydrogen storage properties.

Place, publisher, year, edition, pages
2016. Vol. 120, no 12, 6369-6376 p.
National Category
Chemical Sciences Nano Technology Materials Engineering
Identifiers
URN: urn:nbn:se:su:diva-130137DOI: 10.1021/acs.jpcc.6b00363ISI: 000373416500009OAI: oai:DiVA.org:su-130137DiVA: diva2:929057
Available from: 2016-05-17 Created: 2016-05-09 Last updated: 2016-05-17Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Häussermann, Ulrich
By organisation
Department of Materials and Environmental Chemistry (MMK)
In the same journal
The Journal of Physical Chemistry C
Chemical SciencesNano TechnologyMaterials Engineering

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 10 hits
ReferencesLink to record
Permanent link

Direct link