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Chemical expansion due to hydration of proton conducting perovskite oxide ceramics
(Journal article; Peer reviewed, 2014)
The crystal structures of proton conducting BaZr1-xYxO3-x/2 (BZY05-BZY20) and
BaCe0.8Y0.2O2.9 (BCY20) during hydration/dehydration has been studied by in situ high
temperature X-ray diffraction and thermal analysis. A ...
On the energetics of cation ordering in tungsten-bronze-type oxides
(Journal article; Peer reviewed, 2015)
Oxides with the tetragonal tungsten bronze (TTB) structure are well-known ferroelectrics that show a
large flexibility both with respect to chemical composition and cation ordering. Two of the simplest
compounds in this ...
Diffusion of alkali metals in the first stage graphite intercalation compounds by vdW-DFT calculations
(Journal article; Peer reviewed, 2015)
Diffusion of alkali metal cations in the first stage graphite intercalation compounds (GIC) LiC6, NaC6, NaC8 and KC8 has been investigated with density functional theory (DFT) calculations using the optPBE-vdW van der Waals ...
Origin of ferroelectric polarization in tetragonal tungsten-bronze-type oxides
(Journal article; Peer reviewed, 2016)
The origin of ferroelectric polarization in tetragonal tungsten-bronze- (TTB-) type oxide strontium barium niobate (SBN) is investigated using first-principles density functional calculations. We study in particular the ...
Solid solubility and phase transitions in the system LaNb1-xTaxO4
(Journal article; Peer reviewed, 2008)
The solid solubility between LaNbO4 and LaTaO4 was investigated by X-ray diffraction, and a two-phase region was observed in the composition region LaNb1−xTaxO4 where 0.4⩽x⩽0.8. Single-phase LaNb1−xTaxO4 (0⩽x⩽0.4) with the ...
Van der Waals density functional study of the energetics of alkali metal intercalation in graphite
(Journal article; Peer reviewed, 2014)
We report on the energetics of intercalation of lithium, sodium and potassium in graphite by density functional theory using recently developed van der Waals (vdW) density functionals. First stage intercalation compounds ...
Revisiting the Crystal Structure of Rhombohedral Lead Metaniobate
(Journal article; Peer reviewed, 2014)
Lead metaniobate (PbNb2O6) can exist both as a stable rhombohedral and a metastable
orthorhombic tungsten-bronze-type polymorph. While the orthorhombic is a
well-known ferroelectric material, the rhombohedral polymorph ...
A van der Waals Density Functional Study of MoO3 and Its Oxygen Vacancies
(Journal article; Peer reviewed, 2016)
The electronic structure of layered molybdenum trioxide MoO3 is highly sensitive to changes in oxygen stoichiometry as Mo6+ has an empty 4d shell. Applications of MoO3 are responsive to small changes in vacancy concentration, ...
Local Structure of Disordered Bi0.5K0.5TiO3 Investigated by Pair Distribution Function Analysis and First-Principles Calculations
(Journal article; Peer reviewed, 2017)
We investigate A-site cation ordering in the ferroelectric perovskite Bi0.5K0.5TiO3 (BKT) by density functional theory (DFT) calculations and synchrotron X-ray total scattering. Using BKT as a prototypical lead-free ...
Electronic properties of reduced molybdenum oxides
(Journal article; Peer reviewed, 2017)
The electronic properties of MoO3 and reduced molybdenum oxide phases are studied by density functional theory (DFT) alongside characterization of mixed phase MoOx films. Molybdenum oxide is utilized in compositions ranging ...