Abstract:
Much needed advances in technology to tackle the problems of sustainable energy
and environment requires continuous efforts to develop new functional materials and
devices that are more energy efficient and eco-friendly. With continued advances
in computational power, algorithms and techniques of simulations, computational
material research plays a key role in predicting and engineering novel materials with
desired properties. In particular, first-principles Density Functional Theory-based
simulations provide fundamental insights into structural stability and properties of
a material under the influence of external stimulii. On the other hand, classical
atomistic modeling of materials helps in the study of their properties at long time
and length scales through use of Molecular Dynamics or Monte Carlo simulations,
possibly with effective Hamiltonian or model constructed from first-principles.
This thesis is divided into three parts based on the kind of technological applications
and functionality of the materials studied. The first part focuses on the
microscopic understanding of the origin of inhomogeneously ordered domain structures
in ferroelectric materials like PbTiO3 and BaTiO3 that can be tuned with
electrical and mechanical boundary conditions. This has relevance to applications
in nano-electro-mechanical systems (NEMS).
