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Research Interests
Dr. Purusottam Jena
Professor
Chemical Physics
The research interests of our group cover a wide variety of topics ranging from atomic
and molecular phyiscs to solid state and chemical phyiscs. The studies are aimed at
understanding properties of novel materials at an atomic scale using state-of-the-art
theoretical techniques. The problems under investigation include: defects and defect
complexes in metals, atomic clusters, surfaces, interfaces, superlattices, and composite
materials.
Electronic structure of imperfect crystalline solids. These studies include point
defects (vacancies, interstitial and substitutional impurities) and their aggregates,
various types of dislocations, grain boundaries, and surfaces. This upsurge in interest
stems not only from the fact that defects in metals are important to technology, but
also from the fact that understanding defects poses many fundamental problems for
theory and experiment. The fact that no metal exists in a 100-percent-pure state makes
it imperative that we aim at a fundamental understanding of the influence of defects on
the host electronic structure. With increasing sophistication in experimental techniques,
it has become apparent that the properties of defects are influenced by the presence of
other defects.
The motivation for this work is, therefore, to understand materials science problems
through electronic structure calculations and their comparison with available
experiments. We are currently studying the interaction of hydrogen and rare gas
impurity atoms with intrinsic lattice defects such as vacancies, micro-voids, and
substitutional impurites. This work involves first principles calculations of the
electronic structure around defect complexes, determination of the equilibrium site
of hydrogen in the presence of lattice defects, the lattice relaxation around defects,
and the binding energy of hydrogen to lattice defects. We use theoretical
techniques based upon local density as well as the Hartree-Fock method.
Atomic clusters. This is a relatively new interdisciplinary field involving
physicists, chemists, and material scientists. Atomic clusters consisting of 2 - 100
atoms are a new class of matter whose electronic and structural properties depend
strongly on their size, shape and composition. Using self-consistent molecular
orbital theories, we are studying the equilibrium structure, electronic, magnetic and
optical properties of homo- and hetero-nuclear clusters. The thermal stability of
free as well as supported clusters are being investigated by carrying out
molecular dynamics simulations. The change in properties with changes in
composition and charge state are being probed to design materials with atomic
dimensions and uncommon properties. Reactions of clusters with hydrogen, propane,
nitric oxide, and other gases are being studied to understand reaction rate and
reaction paths.
Surface, interfaces, superlattices. These studies are aimed at understanding
the nature of dissociation of hydrogen, kinetics of impurity diffusion, relaxation of
atoms and mechanism of adhesion, and magnetic properties.
Publications with Nanostructured Materials Consortium
 Physics Homepage.
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