Melting of FePt nanoparticles studied using DFT.

Thermodynamical stability of different variants of FePt nanoparticles has been studied using DFT molecular dynamics. The melting temperature and general stability at elevated temperatures have been estimated from both energy difference and atomic root-mean-square displacement functions. The investigated systems include multi-shell nanoparticles of iron and platinum with icosahedral symmetry and a magic number of atoms (55): iron-terminated FePt and platinum-terminated FePt.

Phonon confinement and interface lattice dynamics of ultrathin high- rare earth sesquioxide films: the case of EuO on YSZ(001).

The spatial confinement of atoms at surfaces and interfaces significantly alters the lattice dynamics of thin films, heterostructures and multilayers. Ultrathin films with high dielectric constants (high-) are of paramount interest for applications as gate layers in current and future integrated circuits. Here we report a lattice dynamics study of high- EuO films with thicknesses of 21.

Lattice Dynamics and Structural Phase Transitions in EuO.

Using the density functional theory, we study the structural and lattice dynamical properties of europium sesquioxide (EuO) in the cubic, trigonal, and monoclinic phases. The obtained lattice parameters and energies of the Raman modes show a good agreement with the available experimental data. The Eu-partial phonon density of states calculated for the cubic structure is compared with the nuclear inelastic scattering data obtained from a 20 nm thick EuO film deposited on a YSZ substrate.

Phonon mode potential and its contribution to anharmonism.

We present systematic ab-initio study on the phonon mode potential as a source of anharmonicity in the crystal. As an example, the transverse optical (TO) mode potential in PbTe has been fitted to density-functional-theory calculated energies of phonons excited with different amplitudes of mode displacements. The corresponding equation of motion has been analytically and numerically solved in 1D and 2D space, respectively.

Dynamics and stability of icosahedral Fe-Pt nanoparticles.

The structure, dynamics and stability of Fe-Pt nanoparticles have been investigated using DFT-based techniques: total energy calculations and molecular dynamics. The investigated systems included multi-shell and disordered nanoparticles of iron and platinum. The study concerns icosahedral particles with the magic number of atoms (55): iron-terminated Fe43Pt12, platinum-terminated Fe12Pt43, and disordered Fe27Pt28.

Structure and elastic properties of Mg(OH)2 from density functional theory.

The structure, lattice dynamics and mechanical properties of magnesium hydroxide have been investigated by static density functional theory calculations as well as ab initio molecular dynamics. The hypothesis of a superstructure existing in the lattice formed by the hydrogen atoms has been tested. The elastic constants of the material have been calculated with a static deformations approach and are in fair agreement with the experimental data.

Comparative ab initio study of lattice dynamics and thermodynamics of Fe2SiO4- and Mg2SiO4-spinels.

Lattice dynamics and thermodynamic properties of antiferromagnetic Fe(2)SiO(4)-spinel have been studied using density functional theory. Phonon dispersions are obtained for several hydrostatic pressures up to 20 GPa. They are used to calculate thermodynamic properties within the quasiharmonic approximation.