Dylan Cuskelly

Plasmon Responses in the Sodium Tungsten Bronzes

The sodium tungsten bronzes (NaxWO3) are vividly coloured metallic materials where the optical behaviour can be attributed to the bulk plasma frequency occurring in the visible part of the spectrum. A combination of density functional theory (DFT) calculations and experimental electron energy-loss spectroscopy (EELS) was used to assess their bulk and surface plasmon responses. It was observed that NaxWO3 can sustain strong localised surface plasmon resonances (LSPR) with an energy that can be tuned by changing the Na content. They have a stronger plasmonic response when compared to Au and do not suffer from the atmospheric corrosion of Ag, giving them good potential for plasmonic applications.

Miscibility Gap Alloys: A New Thermal Energy Storage Solution

The status of miscibility gap alloys (MGA), which have demonstrated excellent characteristics for thermal storage applications over a wide range of temperatures, is reviewed. MGA remain macroscopically solid whilst delivering latent heat from embedded metal particles supplemented by the sensible heat of the whole material. Heat can be delivered rapidly due to very high thermal conductivity leading to modular solid storage designs which can act as solar boilers for direct steam CSP or other applications. Progress in the manufacture, alloy design and a demonstration of 1.5 kW steam turbine generator with integrated MGA storage unit are briefly described.