Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Physics

Non-Equilibrium Melting And Sublimation Of Graphene Simulated With Two Interatomic Potentials, Brad Steele Jan 2013

Non-Equilibrium Melting And Sublimation Of Graphene Simulated With Two Interatomic Potentials, Brad Steele

USF Tampa Graduate Theses and Dissertations

The mechanisms of the sublimation of graphene at zero pressure and the condensation of carbon vapor is investigated by molecular dynamics (MD) simulations. The interatomic interactions are described by the Reactive Empirical Bond Order potential (REBO). It is found that graphene sublimates at a temperature of 5,200 K. At the onset of sublimation, defects that contain several pentagons and heptagons are formed, that are shown to evolve from double vacancies and stone wales defects. These defects consisting of pentagons and heptagons act as nucleation sites for the gaseous phase. The influence of the interatomic interactions on the sublimation process are …


Magnetization Dynamics And Related Phenomena In Nanostructures, Sayan Chandra Jan 2013

Magnetization Dynamics And Related Phenomena In Nanostructures, Sayan Chandra

USF Tampa Graduate Theses and Dissertations

Collective magnetic behavior in nanostructures is a phenomenon commonly observed in various magnetic systems. It arises due to competing inter/intra–particle interactions and size distribution and can manifest in phenomena like magnetic freezing, magnetic aging, and exchange bias (EB) effect. In order to probe these rather complex phenomena, conventional DC and AC magnetic measurements have been performed along with radio–frequency transverse susceptibility (TS) measurements. We also demonstrate the magnetic entropy change as a parameter sensitive to subtle changes in the magnetization dynamics of nanostructures. The focus of this dissertation is to study the collective magnetic behavior in core-shell nanostructures of Fe/γ–Fe …


Synthesis And Investigations Of Type I And Ii Clathrates Of Group 14, Michael Blosser Jan 2013

Synthesis And Investigations Of Type I And Ii Clathrates Of Group 14, Michael Blosser

USF Tampa Graduate Theses and Dissertations

Clathrates are a class of new materials that have an open-framework structure that allows guest atoms or molecules to be enclosed inside of their polyhedral framework. Varying the number, weight, and size of the guest species in a particular framework allows one to alter the physical properties of the clathrate. This relationship enables one to further the fundamental understanding of the physics and chemistry of the clathrate structure and use this knowledge to "tune" certain properties. This "tunability" of inorganic clathrates is of great interest as it allows one to optimize their physical properties; making them promising candidates for a …