Physics (Theses and Dissertations): Recent submissions
Now showing items 261-280 of 458
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Implications of antiphase boundaries (APBs) on the strain relaxation and magnetotransport properties of Fe3o4 hetero-epitaxial thin films
(Trinity College (Dublin, Ireland). School of Physics, 2007)The strain relaxation and magneto transport properties of epitaxial magnetite (Fe3O4) thin films were studied. Epitaxial Fe3O4 film s were grown on MgO and MgAl2O4 substrates using an Oxygen plasma assisted Molecular beam ... -
Probing outflows from young stars and brown dwarfs
(Trinity College (Dublin, Ireland). School of Physics, 2005)The phenomenon of mass outflow from young stellar objects, is arguably the most spectacular stage in the formation of a star. Much is known about the large scale manifestations of outflows and many breathtaking images ... -
Gamma Ray Bursts : probing burst environments in high redshift galaxies
(Trinity College (Dublin, Ireland). School of Physics, 2008)First discovered in the late 1960s, Gamma Ray Bursts have remained something of a cosmic mystery for almost four decades. It has only been quite recently that the nature of these phenomena is beginning to be understood. ... -
Theoretical studies of doped carbon nanotube-based materials
(Trinity College (Dublin, Ireland). School of Physics, 2008)For the last fifteen years, carbon nanotubes have piqued the interest of many in the materials research community, due to their superlative individual characteristics. One possible route to their technological exploitation ... -
Generation, characterisation and solidification of crystalline microfoams
(Trinity College (Dublin, Ireland). School of Physics, 2008)This study is centered around the spontaneous ordering of equally sized microbubbles on top of a liquid pool, forming wet crystalline microfoams. This type of ordering was firstly observed by Bragg and Nye in 1947 and only ... -
Polymer crystallisation of a reinforcement mechanism for polymer-carbon nanotube composites
(Trinity College (Dublin, Ireland). School of Physics, 2005)Two semi-crystalline polymers, poly(mphenylenevinylene-co-2,5-dioctyloxy-p-phenylenevinylene) (PmPV) and poly(vinyl alcohol) (PVOH), have been doped with carbon nanotubes. In the case of PmPV, well-graphitised arc discharge ... -
Electronic and lattice structure of the strongly correlated transition metal oxides Fe3O4 and LaSr2Mn2O7 : a hybrid density functional study
(Trinity College (Dublin, Ireland). School of Physics, 2007)This thesis is a theoretical study of the electronic and lattice structure of the inverse spinel magnetite (Fe3O4) and the half-doped bilayered manganite system LaSr2 Mn2O7 . Both systems are strongly correlated transition ... -
Theoretical and computational aspects of electronic transport at the nanoscale
(Trinity College (Dublin, Ireland). School of Physics, 2007)The problem of electronic transport in systems comprising only a handful of atoms is one of the most exciting branches of nanoscience. The aim of this work is to address the issue of non-equilibrium transport at the ... -
Studies of the oxidation of Mo(110) : a method for nanowire growth
(Trinity College (Dublin, Ireland). School of Physics, 2008)In this dissertation the oxidation of the molybdenum (110) surface was studied at 900 and 1000 °C and 1 x 10-6 Torr oxygen pressure. Through the use of low energy electron diffraction (LEED), Auger electron spectroscopy ... -
Polarisation effects in semiconductor optical amplifiers
(Trinity College (Dublin, Ireland). School of Physics, 2007)Optical switches based on SOAs are critical elements for the implementation of alloptical gating. The various wavelength conversion schemes are limited by their polarisation sensitivity. The polarisation sensitivity of ... -
Issues relating to the application of monolithic tuneable laser diodes to multi-species gas detection
(Trinity College (Dublin, Ireland). School of Physics, 2005)Tuneable Diode Laser Absorption Spectroscopy (TDLAS) technology for gas sensing has had reliance on, and has benefited from, devices developed for the optical communications sector, namely distributed feedback laser diodes. ... -
Implementation of self interaction free density functional methods and applications to dilute magnetic semiconductors
(Trinity College (Dublin, Ireland). School of Physics, 2008)The present thesis mainly deals with the implementation of self interaction free density functional methods in a numerically efficient density functional theory code SIESTA and the application of the said methods in ab-inito ... -
Magnetic field effects on electrodeposition and the properties of electrodeposited nickel and nickel-copper
(Trinity College (Dublin, Ireland). School of Physics, 2004)The association of magnetism and electrodeposition is studied from two separate perspectives. Firstly the effect of an applied magnetic field on the deposition process and secondly the production of magnetic materials by ... -
Nanomechanical forming studies of thin polymer films
(Trinity College (Dublin, Ireland). School of Physics, 2008)Nanoimprint is a technique that involves mechanical patterning using a rigid patterned stamp on a deformable thin film to produce nanostructures. It is also a technique that is the focus of much research because of the ... -
The impact of protostellar jets on their environment
(Trinity College (Dublin, Ireland). School of Physics, 2005)The nature of the accelerated and heated gas along collimated outflows emanating from deeply embedded protostars is investigated. By analysing the shock structures and excitation conditions it is possible to deduce information ... -
A novel scanning probe micoscopy study of the (110) surface of rutile titanium dioxide
(Trinity College (Dublin, Ireland). School of Physics, 2008)This work describes the application of a novel multi-parameter scanning probe technique to the study of a model semiconductor and a metal oxide surface. Our novel scanning probe technique enables the simultaneous measurement ... -
Numerical investigation of self-pulsation for narrow stripe A1GaAs/GaAs and InGaAsP/InP semiconductor laser diodes
(Trinity College (Dublin, Ireland). School of Physics, 2004)Self-pulsation in laser diodes is the process by which pulsed light is emitted from the laser while under direct current injection. As a result of their low relative intensity noise under feedback conditions, and high ... -
On the ejection of high velocity massive stars from star clusters
(Trinity College (Dublin, Ireland). School of Physics, 2008)OB1 runaways are massive, early-type, high velocity stars which have been ejected from their parent birthplaces. Some of which have velocities above 200km/s. Two mechanisms are plausible explanations for these objects: A ... -
Molecular engineering of conjugated organic molecule and carbon nanotube assemblies - a linear and nonlinear spectroscopic study
(Trinity College (Dublin, Ireland). School of Physics, 2007)Single walled carbon nanotubes (SWNTs) possess unique structural, mechanical and electronic properties, and are thus promising materials for a host of future applications. However, their potential is limited in that they ... -
Three-dimensional models of astrophysical magnetohydrodynamical jets
(Trinity College (Dublin, Ireland). School of Physics, 2007)In the previous fifty years it has become clear that jets and outflows play a vital role in the formation of stars and com pact objects. Jets from young stellar objects typically show Herbig-Haro knots and bow shocks. ...
