Anindya Roy

First-principles study of high-field piezoelectricity in tetragonal PbTiO3

We calculate from first principles the nonlinear piezoelectric response of ferroelectric PbTiO3 for the case of a polarization-enhancing electric field applied along the tetragonal axis. We focus mainly on the case of fixed in-plane lattice constants, corresponding to epitaxially constrained thin films. We find that the dependence of the c/a ratio on electric field is almost linear in the range up to 500 MV/m with little saturation. This result contrasts with expectations from Landau-Devonshire approaches based on experimental results obtained at lower fields but is in qualitative agreement with a recent experiment in which higher fields were attained using pulsed-field methods. We also study cases in which the in-plane epitaxy constraint is removed, or an artificial negative pressure is applied, or both. These calculations demonstrate that PbTiO3 can show a strikingly nonlinear piezoelectric response under modified elastic boundary conditions.

Estimates of the thermal conductivity and the thermoelectric properties of PbTiO

The lattice thermal conductivity (

_3

\kappa_{\rm L}

from first principles

) of PbTiO

Promoting sulfur adsorption using surface Cu sites in metal–organic frameworks for lithium sulfur batteries

_3

Tetrahedral bonding in twisted bilayer graphene by carbon intercalation

(PTO) is estimated using a combination of {\em ab initio} calculations and semiclassical Boltzmann transport equation. The computed

Amorphous ZnO-Based Compounds as Thermoelectrics

\kappa_{\rm L}

In-code Comments as a Self-explanation Strategy for Computational Science Education

is remarkably low, nearly comparable with the

Multiphysics Simulations of Lithiation-Induced Stress in Li1+xTi2O4 Electrode Particles

\kappa_{\rm L}

Exploring Undergraduate Students’ Computational Literacy in the Context of Problem Solving

of good thermoelectric materials such as PbTe. In addition, a semiclassical analysis of the electronic transport quantities is presented, which suggests excellent thermoelectric properties, with a figure of merit