David G. Pettifor

  • Citations Per Year
Learn More
Anisotropy of intermolecular and molecule-substrate interactions holds the key to controlling the arrangement of fullerenes into 2D self-assembled monolayers (SAMs). The chemical reactivity of fullerenes allows functionalization of the carbon cages with sulfur-containing groups, thiols and thioethers, which facilitates the reliable adsorption of these(More)
Surface templating via self-assembly of hydrogen-bonded molecular networks is a rapidly developing bottom-up approach in nanotechnology. Using the melamine-PTCDI molecular system as an example we show theoretically that the network stability in the parameter space of temperature versus molecular coupling anisotropy is highly restricted. Our kinetic Monte(More)
First-principles density-functional calculations of the atomic and electronic structure of Co/SrTiO3 /Co ~001! magnetic tunnel junctions ~MTJ’s! are performed. Different interface terminations are considered and the most stable structure with the TiO2 termination is identified based on energetics of adhesion. The calculated electronic structure of the(More)
Experimental evidence has been found for the existence of small single wall carbon nanotubes with diameters of 0.5 and 0.33 nm by high resolution transmission electron microscopy, and their mechanical stability was investigated using tight-binding molecular dynamics simulations. It is shown that, while the carbon tubes with diameters smaller than 0.4 nm are(More)
Most experts agree that it is too early to say how quantum computers will eventually be built, and several nanoscale solid-state schemes are being implemented in a range of materials. Nanofabricated quantum dots can be made in designer configurations, with established technology for controlling interactions and for reading out results. Epitaxial quantum(More)
Novel analytic bond-order potentials (BOPs) may be derived for atomistic simulations by coarse-graining the electronic structure within the orthogonal two-centre tight-binding (TB) representation. We show that these BOPs allow the concept of single, double, triple and conjugate bonds in carbon systems to be quantified, so that they provide the first(More)
Iridium is unique among the face-centered cubic metals in that it undergoes brittle cleavage after a period of plastic deformation under tensile stress. Atomistic simulation using a quantum-mechanically derived bond-order potential shows that in iridium, two core structures for the screw dislocation are possible: a glissile planar core and a metastable(More)
An accurate density-functional method is used to study systematically half-metallic ferromagnetism and stability of zincblende phases of 3d-transition-metal chalcogenides. The zincblende CrTe, CrSe, and VTe phases are found to be excellent half-metallic ferromagnets with large half-metallic gaps (up to 0.88 eV). They are mechanically stable and(More)