Pressure-induced structural phase transition in NaBH4
2005 (English)In: Physical Review B, ISSN 1198-0121, Vol. 72, no 5, 054125- p.Article in journal (Refereed) Published
We present a combined experimental and theoretical study of the technologically important NaBH4 compound under high pressure. Using Raman spectroscopy at room temperature, we have found that NaBH4 undergoes a structural phase transformation starting at 10.0 GPa with the pure high pressure phase being established above 15.0 GPa. In order to compare the Raman data recorded under high pressure with the low temperature tetragonal phase of NaBH4, we have also performed a cooling experiment. The known order-disorder transition from the fcc to the tetragonal structure was then observed. However, the new high pressure phase does not correspond to this low temperature structure. Using first principle calculations based on the density functional theory, we show that the new high pressure phase corresponds to the α-LiAlH4 type structure. We have found a good agreement between the measured and calculated transition pressures. Additionally, we present the electronic structure of both the fcc and the high pressure phases.
Place, publisher, year, edition, pages
2005. Vol. 72, no 5, 054125- p.
hydrogen storage, borates, electronic structure
IdentifiersURN: urn:nbn:se:uu:diva-77822DOI: doi:10.1103/PhysRevB.72.054125OAI: oai:DiVA.org:uu-77822DiVA: diva2:105735