Physics (Theses and Dissertations): Recent submissions
Now showing items 141-160 of 458
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Atomic Diffusion and Pulsation in Post-Common-Envelope Binary Stars
(Trinity College Dublin. School of Physics. Discipline of Physics, 2020)I study the evolution of peculiar low-mass, evolved stars. Two groups of interest are the core-helium-burning hot subdwarfs and the shell-hydrogen-burning low-mass pre-white dwarfs. Stars in both groups have had previous ... -
Structures of columnar packings with soft and hard spheres
(Trinity College Dublin. School of Physics. Discipline of Physics, 2020)Columnar structures refer to dense cylindrical packings of spheres. They are ubiquitous throughout botany, foams, and have recently also become popular in nanoscience. We investigate such structures by carrying out computer ... -
Multi-scale analysis of current-driven spin dynamics in magnetic tunnel junctions
(Trinity College Dublin. School of Physics. Discipline of Physics, 2020)Magnetic materials are of fundamental importance for the next generation of sensing and storage applications. The operating principle of such devices is based upon manipulating the orientation of the atomic magnetic moments. ... -
Exfoliation and sensing application of 2D - materials
(Trinity College Dublin. School of Physics. Discipline of Physics, 2020)In the past decade, graphene and layered material such as Transition metal dichalcogenides (TMDs) and Transition metal oxides (TMOs) have been investigated for their importance in several applications. For example, these ... -
The Optics and Photonics of Two-Dimensional Nanomaterials
(Trinity College Dublin. School of Physics. Discipline of Physics, 2020)In this work, by using a broadspectrum angle-resolved absorption technique, we studied enhanced absorption from multi-layered materials with near-zero dielectric permittivity in the near-infrared. These materials, known ... -
Material selection for Spin-Transfer-Torque Magnetic Random Access Memories: a High-Throughput approach
(Trinity College Dublin. School of Physics. Discipline of Physics, 2020)A Spin-Transfer-Torque Magnetic Random Access Memory (STT-MRAM) is a complex multilayered structure, whose sensitive element is formed by two ferromagnetic layers sandwiching an insulator, acting as a tunnel barrier. The ... -
Topological photonics with anisotropic materials
(Trinity College Dublin. School of Physics. Discipline of Physics, 2020)In this thesis we investigate several aspects of the topological characterisation of light propagating through matter, or topological photonics. Throughout we will focus on anisotropic dielectrics in which the optical ... -
Graphene-nonlinear optical properties and modelocking capabilities
(Trinity College Dublin. School of Physics. Discipline of Physics, 2020)In this thesis, graphene saturable absorber mirror's (SAM) potential for mode-locking ultrafast lasers has been demonstrated, in particular at 2 μm. The saturable absorption of graphene thin films (prepared via drop-casting ... -
Plasmon resonance studies in silver nanoparticles arrays grown by Atomic Terrace Low Angle Shadowing (ATLAS)
(Trinity College (Dublin, Ireland). School of Physics, 2009)Nanotechnology refers to the study of nanomaterials aiming to understand the physical properties and phenomena that materials show at the nanometre scale. A key goal in nanotechnology is acquiring the ability to manipulate ... -
Defect engineering of ultra-thin layered molybdenum disulfide towards novel memristive and optoelectronic applications
(Trinity College Dublin. School of Physics. Discipline of Physics, 2019)In the ever-evolving field of nanoelectronics, new paradigms are constantly sought-after to improve the performance of next-generation circuit components. In the last decade, two-dimensional (2D) semiconductors have emerged ... -
Mechanical properties of advanced nanosturctured composite fibres containing carbon nanotubes and graphene
(Trinity College (Dublin, Ireland). School of Physics, 2012)A comprehensive study of the mechanical properties of coagulation spun poly(vinyl) alcohol-nanotube composite fibres has been performed. A method has been developed to control and measure the nanotube volume fraction, Vf, ... -
Spin injection, detection and magnetoresistive effects in organic systems
(Trinity College (Dublin, Ireland). School of Physics, 2015)Because of the weak spin-orbit interaction in organic systems, very long spin lifetimes are intuitively expected. The prospect of cheap and flexible spintronics devices makes organic semiconductors an attractive class of ... -
Magnetic and transport properties of magnetite based nanostructures
(Trinity College (Dublin, Ireland). School of Physics, 2009)In this thesis, we investigate the magnetic and transport properties of magnetite based nanostructures. We in particular investigate the magnetization and surface Verwey transition of magnetite thin film, interlayer ... -
Electron paramagnetic resonance characterisation of defects in HfO2 and ZrO2 powders and films
(Trinity College (Dublin, Ireland). School of Physics, 2009)Electron Paramagnetic Resonance (EFR) measurements have been made on a variety of commercially available samples of monoclinic HfO2 and ZrO2 powders and also on HfO2 and ZrO2 films deposited on silicon by electron ... -
Spectroscopic studies of self-assembled plasmonic nanoparticle arrays
(Trinity College (Dublin, Ireland). School of Physics, 2011)In this thesis an alternative self-assembled deposition technique able to produce nanoparticle (NP) arrays ordered on the macroscale is described. Stepped surfaces are produced by high temperatures annealing AI3O4 (0001) and ... -
Step-induced defects in thin films and the effect on their electrical and magnetic properties
(Trinity College (Dublin, Ireland). School of Physics, 2015)This thesis investigates step-induced defects in thin films and their effect on the electrical and magnetic properties. Stepped epitaxial Fe3O4 thin films with different thickness were fabricated and their magnetic properties ... -
Electric discharges in laser produced plasmas
(Trinity College (Dublin, Ireland). School of Physics, 2010)This thesis describes the results of an investigation of the effects of a medium voltage (0.1-1 kV), low-inductance discharge in a laser produced plasma. Discharging was done in vacuum using coaxial discharge cells of ... -
Dye laser micro-fluidic amplifiers
(Trinity College (Dublin, Ireland). School of Physics, 2011)Dye lasers, based on micro-fluidic systems, have been the focus of increasing attention in recent years. Whereas micro-fluidics networks, such as a 'lab-on-a-chip', involve expensive and complicated fabrication processes, ... -
Computational methods for electron transport and their application in nanodevices
(Trinity College (Dublin, Ireland). School of Physics, 2009)The present thesis deals with the development of theoretical and computational tools for the first principles study of ground state and electronic transport properties of nanoscale devices and the application of these tools ... -
Investigating of gas sensing and diode laser frequency stabilisation using novel photonic microstructures
(Trinity College (Dublin, Ireland). School of Physics, 2010)Laser spectroscopy is nowadays a widespread research field with countless applications across multiple disciplines. In particular, the application to gas sensing in the near-infrared region significantly benefits from the ...
