Related papers: Crystal field and related phenomena in hexagonal c…
The lattice distortion parameter $\delta \equiv c/a-\sqrt{8/3}$ has been calculated as a function of molar volume for the hcp phases of He, Ar, Kr and Xe. Results from both semi-empirical potentials and density functional theory are…
A cascade of phase transitions from square to hexagonal lattice is studied in 2D system of particles interacting via core-softened potential. Due to the presence of two length-scales of repulsion, different local configurations with four,…
A real-space approach for the calculation of the Moir\'e lattice parameters for superstructures formed by a set of rotated hexagonal 2D crystals such as graphene or transition-metal dichalcogenides, is presented. Apparent Moir\'e lattices…
The phase field crystal model allows the study of materials on atomic length and diffusive time scales. It accounts for elastic and plastic deformation in crystal lattices, including several processes such as growth, dislocation dynamics,…
We calculate mean square deviations for crystals in one and two dimensions. For the two dimensional lattices, we consider several distinct geometries (i.e. square, triangular, and honeycomb), and we find the same essential phenomena for…
Lattices in three dimensions are oft studied from the ``reciprocal space'' perspective of diffraction. Today, the full lattice of a crystal can often be inferred from direct-space information about three sets of non-parallel lattice planes.…
We study a system of particles in two dimensions interacting via a dipolar long-range potential $D/r^3$ and subject to a square-lattice substrate potential $V({\bf r})$ with amplitude $V$ and lattice constant $b$. The isotropic interaction…
We have performed ultrasonic measurements on single-crystalline URu2Si2 with pulsed magnetic fields, in order to check for possible lattice instabilities due to the hybridized state and the hidden-order state of this compound. The elastic…
X-ray diffraction experiments under pressure in a diamond anvil cell have been performed to gauge any response of the crystalline lattice of URu2Si2 to the "hidden order" or antiferromagnetic transitions, the latter of which is accessible…
We use neutron scattering and bulk property measurements to determine the single-ion crystal-field Hamiltonians of delafossites $\rm KErSe_2$ and $\rm CsErSe_2$. These two systems contains planar equilateral triangular Er lattices arranged…
A consistent, small scale description of plastic motion in a crystalline solid is presented based on a phase field description. By allowing for independent mass motion given by the phase field, and lattice distortion, the solid can remain…
We study the kinetics of the nematic-isotropic transition in a two-dimensional liquid crystal by using a lattice Boltzmann scheme that couples the tensor order parameter and the flow consistently. Unlike in previous studies, we find the…
In solids, crystal field splitting refers to the lifting of atomic orbital degeneracy by the surrounding ions through the static electric field. Similarly, we show that the degenerated $d$ orbitals, which were derived in the harmonic…
A model describing the dynamics of crystal exciton states on a hexagonal lattice has been studied. The hamiltonian includes terms describing the movement of the exciton throughout the crystal. Here we generalize the hamiltonian by including…
Crystal structures of simple metals and binary alloy phases based on the close-packed hexagonal structure are analyzed within the model of Fermi sphere-Brillouin zone interactions to understand distortions and superlattices. Examination of…
We investigate the crystal structure, magnetic properties, and crystalline-electric field of tetragonal, $I4_1/amd$, NaCeO$_2$. In this compound, Ce$^{3+}$ ions form a tetragonally elongated diamond lattice coupled by antiferromagnetic…
A modification of structural phase-field crystal (XPFC) model for an arbitrary pair interaction potential is presented. Formation of 1D and 2D structures for the Lennard-Jones (LJ) potential was studied numerically. The equilibrium lattice…
Point defects such as interstitials, vacancies, and impurities in otherwise perfect crystals induce complex displacement fields that are of long-range nature. In the present paper we study numerically the response of a two-dimensional…
Understanding deformation in polycrystalline metals is critical to use them in high-value high-risk applications. We present in-situ characterisation of plastic deformation of zirconium, a hexagonal closed packed (HCP), metal. Analysis of…
We introduce a Phase Field Crystal (PFC) model for particles with n-fold rotational symmetry in two dimensions. Our approach is based on a free energy functional that depends on the reduced one-particle density, the strength of the…