Browsing School of Physics by Sponsor "Science Foundation Ireland"
Now showing items 21-40 of 139
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Correcting for probe wandering by precession path segmentation
(2023)Precession electron diffraction has in the past few decades become a powerful technique for structure solving, strain analysis, and orientation mapping, to name a few. One of the benefits of precessing the electron beam, ... -
Correlation between perpendicular exchange bias and magnetic anisotropy in IrMn/[Co/Pt](n) and [Pt/Co](n)/IrMn multilayers
(American Institute of Physics, 2005)Perpendicular exchange bias has been observed for IrMn/[Co/Pt]n and [Pt/Co]n/IrMn multilayers in the as-deposited state. The exchange bias field is largest when the IrMn film is grown on magnetically saturated Co/Pt ... -
Correlation effects in p-electron magnets: the case of RbO_2
(2009)We present results of GGA+U calculations for the "d^0 magnet" RbO_2, where magnetic properties are due to partially filled oxygen p orbitals. We show that on-site interactions on the oxygen sites lead to a strong tendency ... -
The Crystal Structure of Bubbles in the Wet Foam Limit (Amendment)
(Royal Society of Chemistry, 2006)We have observed a rich variety of three-dimensional crystal and defect structures spontaneously formed by small (diameter 200 mm) bubbles in a wet foam. The observations confirm and extend those made by Bragg and Nye ... -
Crystallographic Characterisation of Ultra-Thin, or Amorphous Transparent Conducting Oxides ? The Case for Raman Spectroscopy
(2020)The electronic and optical properties of transparent conducting oxides (TCOs) are closely linked to their crystallographic structure on a macroscopic (grain sizes) and microscopic (bond structure) level. With the increasing ... -
Determination of internal loss and quasi-fermi level separation from the amplified spontaneous emission (ASE) spectrum of Fabry-Perot (FP) semiconductor lasers
(IEEE, 2006)The net modal gain and the un-amplified spontaneous emission (ASE) coupled into the laser waveguide mode are extracted from the ASE spectrum of Fabry?PErot semiconductor lasers by the Fourier transform method with a ... -
Directly accessing octave-spanning dissipative Kerr soliton frequency combs in an AlN microresonator
(2021)Self-referenced dissipative Kerr solitons (DKSs) based on optical microresonators offer prominent characteristics allowing for various applications from precision measurement to astronomical spectrometer calibration. To ... -
Doping controlled roughness and defined mesoporosity in chemically etched silicon nanowires with tunable conductivity
(2013)By using Si(100) with different dopant type (n(++)-type (As) or p-type (B)), we show how metal-assisted chemically etched (MACE) nanowires (NWs) can form with rough outer surfaces around a solid NW core for p-type NWs, ... -
Effect of epitaxial strain on the cation distribution in spinel ferrites CoFe(2)O(4) and NiFe(2)O(4): A density functional theory study
(American Institute of Physics, 2011)The effect of epitaxial strain on the cation distribution in spinel ferrites CoFe(2)O(4) and NiFe(2)O(4) is investigated by GGA+U total energy calculations. We obtain a very strong (moderate) tendency for cation inversion ... -
Effect of Hubbard U on the construction of low-energy Hamiltonians for LaMnO(3) via maximally localized Wannier functions
(American Physical Society, 2011)We use maximally localized Wannier functions to construct tight-binding (TB) parametrizations for the e(g) bands of LaMnO(3) based on first-principles electronic structure calculations. We compare two different ways to ... -
The effect of magnetic annealing on barrier asymmetry in Co40Fe40B20/MgO magnetic tunnel junctions
(2010)We demonstrate that high-quality magnetic tunnel junctions with Co40Fe40B20 electrodes and crystalline MgO barriers, which show a 230% tunneling magnetoresistance ratio at room temperature, can be successfully fabricated ... -
Effect of molecular conformations on the electronic transport in oxygen-substituted alkanethiol molecular junctions
(2018)The relationship between the molecular structure and the electronic transport properties of molecular junctions based on thiol-terminated oligoethers, which are obtained by replacing every third methylene unit in the ... -
The Effect of Network Formation on the Mechanical Properties of 1D:2D Nano:Nano Composites
(2018)Mixtures of 1D carbon nanotubes and 2D nanosheets are important in electrochemical applications where the nanosheets are the active material, while the nanotubes provide electrical conductivity and mechanical reinforcement. ... -
Effect of ZnS shell thickness on the phonon spectra in CdSe quantum dots
(American Physical Society, 2003)The evolution of the optical phonon spectra of colloidal core/shell CdSe/ZnS quantum dots with an increase of the shell thickness from 0.5 to 3.4 monolayers has been studied by resonant Raman spectroscopy. The results ... -
Eigenstate Thermalisation in a Locally Perturbed Integrable System
(2020)Eigenstate thermalization is widely accepted as the mechanism behind thermalization in generic isolated quantum systems. Using the example of a single magnetic defect embedded in the integrable spin-1/2 XXZ chain, we show ... -
The Electro-Optical Performance of Silver Nanowire Networks
(2019)Networks of metallic nanowires have the potential to meet the needs of next-generation device technologies that require flexible transparent conductors. At present, there does not exist a first principles model capable of ... -
Electron trapping by neutral pristine ferroelectric domain walls in BiFeO3
(2018)First-principles calculations for pristine neutral ferroelectric domain walls in BiFeO3 reveal that excess electrons are selectively trapped by the domain walls, while holes are only weakly attracted. Such trapped excess ... -
Energy Current Rectification and Mobility Edges
(2019)We investigate how the presence of a single-particle mobility edge in a system can generate strong energy current rectification. Specifically, we study a quadratic bosonic chain subject to a quasiperiodic potential and ...