The session organizers would like to invite researchers to participate in a minisymposium titled "Multiscale constitutive modeling of materials" at the 11th US NATIONAL CONGRESS ON COMPUTATIONAL MECHANICS (USNCCM 11) to be held in Minneapolis, Minnesota from July 25-29, 2011.
We impose uniform electric fields both parallel and normal to 180^o ferroelectric domain walls in PbTiO3 and obtain the equilibrium structures using the method of anharmonic lattice statics. In addition to Ti-centered and Pb-centered perfect domain walls, we also consider Ti-centered domain walls with oxygen vacancies. We observe that electric field can increase the thickness of the domain wall considerably. We also observe that increasing the magnitude of electric field we reach a critical electric field E^c; for E > E^c there is no local equilibrium configuration.
It is with the deepest sadness that I inform you that Professor Jerrold E. Marsden passed away on September 21.
http://www.cds.caltech.edu/~marsden/
Joint Postdoctoral Fellow Position at KAUST
and Georgia Institute of Technology — Accepting applications until the
position is filled
We have one more opening and have no U.S. visa waiver requirement anymore.
Using the method of anharmonic lattice statics, we calculate the equilibrium structure of steps on 180^o ferroelectric domain
Joint Postdoctoral Fellow Position at KAUST and Georgia Institute of Technology — Accepting applications until the position is filled
We have one more opening and have no U.S. visa waiver requirement anymore.
In this letter we obtain the finite-temperature structure
of 180^o domain walls in PbTiO_3 using a quasi-harmonic
lattice dynamics approach. We obtain the temperature dependence of
the atomic structure of domain walls from 0 K up to room
temperature. We also show that both Pb-centered and Ti-centered
180^o domain walls are thicker at room temperature; domain
wall thickness at T=300 K is about three times larger than that of
T=0 K. Our calculations show that Ti-centered domain walls have a
In this paper we first obtain the order of stress singularity for a dynamically propagating self-affine fractal crack. We then show that there is always an upper bound to roughness, i.e. a propagating fractal crack reaches a terminal roughness. We then study the phenomenon of reaching a terminal velocity. Assuming that propagation of a fractal crack is discrete, we predict its terminal velocity using an asymptotic energy balance argument. In particular, we show that the limiting crack speed is a material-dependent fraction of the corresponding Rayleigh wave speed.
In this paper we extend the classical method of lattice dynamics to defective crystals with partial symmetries. We start by a nominal defect configuration and first relax it statically. Having the static equilibrium configuration, we use a quasiharmonic lattice dynamics approach to approximate the free energy. Finally, the defect structure at a finite temperature is obtained by minimizing the approximate Helmholtz free energy. For higher temperatures we take the relaxed configuration at a lower temperature as the reference configuration.
In this paper, we study the effect of normal and shear strains and
oxygen vacancies on the structure of 180^o ferroelectric
domain walls in PbTiO_3.
