https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Corrosion processes of silver nanoparticles https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50089 Wed 12 Jul 2023 14:53:10 AEST ]]> Light splitting in nanoporous gold and silver https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:17410 Sat 24 Mar 2018 08:01:37 AEDT ]]> An introduction to the calculation of valence EELS: quantum mechanical methods for bulk solids https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:19315 Sat 24 Mar 2018 07:51:53 AEDT ]]> Applications and theoretical simulation of low-loss electron energy-loss spectra https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:4743 Sat 24 Mar 2018 07:21:06 AEDT ]]> Crystal structures, electrical properties, and electron energy-loss spectroscopy of the sodium and potassium tetragonal tungsten bronzes https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38283 xWO3) are non-stoichiometric metal oxides which have attracted interest for their potential applications in plasmonics. Although the cubic structures of the sodium tungsten bronzes (NaxWO3) have been extensively studied, reports into the tetragonal-II structures (TII-) of any tungsten bronze are comparatively rare. In this work, TII-NaxWO3 and TII-KxWO3 were prepared by a furnace-assisted method, and characterised by X-ray and neutron powder diffraction, selected-area electron diffraction and electron energy-loss spectroscopy (EELS). A structural determination of TII-NaxWO3 was performed in the space group >I4∕m, in a √2 ✕ √2 ✕ 2 supercell of the P4∕mbm TII-KxWO3 structure. Density functional theory is then used to calculate the valence electronic structure and optical properties to support the EELS measurements. Similar to the cubic structures, the conduction band of TII- is composed of hybridised O 2p and W 5d states, which is filled by electrons donated from the inserted Na or K. The O sites which are in-plane with the W sites are found to have highly localised bands, resulting in low-energy interband transitions in the a∕b direction of the unit cell. In contrast, purely free-electron behaviour is observed in the c-direction below 2 eV. High-quality plasmon resonances are thus only observed in the c-direction, with energy and quality similar to those of the cubic structures. These anisotropic optical properties make TII-NaxWO3 and TII-KxWO3 interesting materials for further study as potential plasmonic materials.]]> Mon 29 Jan 2024 18:47:32 AEDT ]]>