uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Theoretical investigation of xenon-hydrogen solids under pressure using ab initio DFT and GW calculations
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
Show others and affiliations
2011 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 84, no 9, 092101- p.Article in journal (Refereed) Published
Abstract [en]

We have calculated crystal structures and electronic properties of Xe-H(2) compounds under high pressures using first-principles density functional theory calculations and ab-initio random structure searching. We present results for the equation of state, Xe-Xe separations, and the electronic charge transfer between the Xe and H atoms. Our results are broadly consistent with experimental results by M. Somayazulu et al. [Nature Chem. 2, 50 (2010)]. We have in addition calculated the metallization pressure within the GW approximation, finding it to be around 250 GPa, which is close to the maximum pressure reached in the experiment.

Place, publisher, year, edition, pages
2011. Vol. 84, no 9, 092101- p.
National Category
Physical Sciences
URN: urn:nbn:se:uu:diva-158866DOI: 10.1103/PhysRevB.84.092101ISI: 000294402200001OAI: oai:DiVA.org:uu-158866DiVA: diva2:442147
Available from: 2011-09-20 Created: 2011-09-19 Last updated: 2015-05-12Bibliographically approved
In thesis
1. First-Principles Studies of Materials Properties: Pressure-Induced Phase Transitions & Functional Materials
Open this publication in new window or tab >>First-Principles Studies of Materials Properties: Pressure-Induced Phase Transitions & Functional Materials
2015 (English)Doctoral thesis, comprehensive summary (Other academic) [Artistic work]
Abstract [en]

This thesis presents the first-principles studies of materials properties within the framework of the density functional theory (DFT). The thesis constitutes three main parts, i. e., pressure-induced phase transitions in solids, data-storage and clean-energy materials.

The first part focuses on the predictions of crystal structures and the determinations of electronic properties of Xe-H2, FeB4 and Co3O4. Pressurizing Xe-H2 compound yields the formation of H-rich Xe(H2)8, which can exhibit a metallic feature at comparatively lower pressure than pure hydrogen. Hard superconducting FeB4 gets transformed into a novel transparent phase under pressure owing to the enhanced overlap of atomic cores. Spinel Co3O4 undergoes the phase transition from a cubic to a monoclinic because of the charge transfer between cations via the increased 3d-3d interactions.

The second part involves the study of structural and electronic properties of phase-change memory materials (PCMs), i. e., Ge2Sb2Te5 (GST) and Ga-doped In2O3. Van der Waals (vdW) interaction must be considered to obtain accurate crystal structure of layered GST. For Ga-doped In2O3 (GIO), the local structure of amorphous GIO is found to resemble that of amorphous In2O3, except the vicinity of doping atoms. The electronic property of a-GIO is metallic, which considerably differs from the semiconducting feature of the crystalline GIO. This emphasizes the contrast in the conductivity of the crystalline and amorphous upon phase switching of GIO.

The third part associates with the search for clean-energy materials, viz., hydrogen production, hydrogen storage and green Mg-ion batteries. For hydrogen production, the role of intrinsic point defects to water adsorption on ZnO(10-10) surface is investigated. The findings show that the Zn and O defect-sites are energetically not favorable for the water adsorption and dissociation. For the purpose of storing hydrogen in a solid phase, silicene, doped by alkaline and alkaline earth metals, is investigated. We find that Li-doped and Na-doped silicene can attain the superior storage capacity. For cathode material of Mg-ion batteries, Mg2Mo6S8, the diffusivity of Mg ions occurs through an available channel in the bulk with the onset temperature of 200 K.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2015. 69 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1254
Density functional theory, Pressure-induced phase transitions, Ab-initio molecular dynamic, hybrid functional, Ab-initio random structure searching, Phase change material
National Category
Physical Sciences
Research subject
Physics with spec. in Atomic, Molecular and Condensed Matter Physics
urn:nbn:se:uu:diva-251343 (URN)978-91-554-9247-2 (ISBN)
Public defence
2015-06-05, Häggsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 10:15 (English)
Available from: 2015-05-12 Created: 2015-04-15 Last updated: 2015-07-07

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Kaewmaraya, ThanayutAhuja, Rajeev
By organisation
Materials Theory
In the same journal
Physical Review B. Condensed Matter and Materials Physics
Physical Sciences

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: 189 hits
ReferencesLink to record
Permanent link

Direct link