Browsing Physics by Title
Now showing items 1-20 of 1566
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1/f noise in MgO double-barrier magnetic tunnel junctions
(2011)Low frequency noise has been investigated in MgO double-barrier magnetic tunnel junctions (DMTJs) with tunneling magnetoresistance (TMR) ratios up to 250% at room temperature. The noise shows a 1/f frequency spectrum and ... -
1/f noise in the half-metallic oxides CrO2, Fe3O4, and La2/3Sr1/3MnO3
(American Physical Society, 1999)The excess low-frequency (1/f) electrical noise of three representative half-metallic oxides, CrO2, Fe3O4, and La2/3Sr1/3MnO3, has been studied as a function of the temperature (5?300 K) and a magnetic field (up to 12 T). ... -
6 x 6 Effective Mass Hamiltonian for Heterostructures grown on (11N)-oriented substrates
(American Physical Society, 2003)The 6?6 effective mass Hamiltonian for semiconductor heterostructures grown on (11N)-oriented substrates is derived and is compared with the 4?4 model. The hole subbands of InGaAs/InP single quantum wells grown on ... -
A considered application of the Langreth-Lundqvist van der Waals density functional in the context of : open shell molecules, atom centered basis sets, adsorption of graphene into a Bi₂Se₃ slab
(Trinity College (Dublin, Ireland). School of Physics, 2015)The work in this thesis is aimed towards exploring the edge case application of the Langreth-Lundqvist vdW density functional (vdW-DF). The increasing popularity of the vdW-DF functional has resulted in its application ... -
A dynamic study of cavity polaritons
(Trinity College (Dublin, Ireland). School of Physics, 2002)Strong coupling between an atom and a cavity field is a well established phenomenon in the field of cavity quantum electrodynamics. However it was not until 1992 that improvements in growth technology resulted in the advent ... -
A microcantilever-based, dual-mode, quantitative sensing platform for investigation of biological interactions
(Trinity College (Dublin, Ireland). School of Physics, 2013)Since the introduction of the atomic force microscope (AFM) and the subsequent availability of high-quality cantilevers the interest in the application of microcantilevers as biosensors has increased year-on-year. Much of ... -
A miroscopic and spectroscopic characterisation of nanotube/conjugated polymer interactions
(Trinity College (Dublin, Ireland). School of Physics, 2001)A composite material of a conjugated polymer and carbon nanotubes has been developed. The conjugated polymer is poly (p-phenylenevinylene-co-2,5-dioctyloxy-m-phenylenevinylene) (PmPV), a polymer significant for its ... -
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 ... -
A search for X-ray flares in the nuclei of galaxies
(Trinity College (Dublin, Ireland). School of Physics, 2003)Observations of the giant elliptical galaxy NCG 4552 at ultraviolet wavelengths during the early 1990’s showed sharply peaked emission within ~2pc of its centre which initially brightened and then faded. The features of ... -
A study of spin polarization in potential half-metals
(Trinity College (Dublin, Ireland). School of Physics, 2006)The study presented in this thesis has been concerned with measuring spin polarisation in magnetic materials using two methods: i) measurement of magnetoresistance in room temperature point contacts and ii) Point Contact ... -
A study of the film growth environment in pulsed laser deposition of gallium nitride
(Trinity College (Dublin, Ireland). School of Physics, 2004)This thesis describes a study of the deposition requirements for growth of stoichiometric GaN thin films using pulsed laser deposition. Growth has been carried out using either ceramic GaN or metal (solid and liquid) Ga ... -
A theoretical study of the strain-modified RKKY interaction in magnetically doped carbon materials
(Trinity College (Dublin, Ireland). School of Physics, 2015)Graphene-related materials continue to be in the scientific limelight due to near-continuous discoveries regarding their properties and production. The applications envisaged for these super materials are numerous and ... -
Ab Initio calculation of parameters for electron and spin transport in organic crystals
(Trinity College Dublin. School of Physics. Discipline of Physics, 2018)Organic semiconductors offer several crucial advantages over their inorganic counterparts in electronic and spintronic applications. Besides offering structural advantages such as variety and flexibility, organic semiconductors ... -
Ab initio calculation of the biasdependent transport properties of Mn12 molecules
(2009)The bias-dependent transport properties of a device constructed by sandwiching a Mn 12 single molecule magnet between gold electrodes are investigated within an ab initio framework combining the nonequilibrium Green?s ... -
Ab initio electron theory for magnetism in Fe: Pressure dependence of spin-wave energies, exchange parameters, and Curie temperature
(American Physical Society, 2003)The spin-wave spectra for bcc Fe at various lattice constants are calculated by the ab initio density functional electron theory for various lattice constants, and the exchange parameters of a Heisenberg model are determined ... -
Ab initio study of electron transport in dry poly(G)-poly(C) A-DNA strands
(2010)The bias-dependent transport properties of short poly (G)-poly(C) A-DNA strands attached to Au electrodes are investigated with first-principles electronic-transport methods. By using the nonequilibrium Green's function ... -
Ab initio study on the magnetostructural properties of MnAs
(2006)The magnetic and structural properties of MnAs are studied with ab initio methods and by mapping total energies onto a Heisenberg model. The stability of the different phases is found to depend mainly on the volume and ... -
Ab initio theory for current-induced molecular switching: Melamine on Cu(001)
(2013)Melamine on Cu(001) is mechanically unstable under the current of a scanning tunneling microscope tip and can switch among configurations. However, these are not equally accessible, and the switching critical current depends ... -
Ab initio transport across bismuth selenide surface barriers.
(2014)We investigate the effect of potential barriers in the form of step edges on the scattering properties of Bi2Se3(111) topological surface states by means of large-scale ab initio transport simulations. Our results demonstrate ...
