Nanocrystalline europium doped yttria was synthesized using a chemical vapor technique. The powder was characterized by x-ray diffraction, transmission electron microscopy, and ultraviolet spectroscopy. For the first time it was possible to obtain single phase Y2O3:Eu nanoparticles crystallized in the cubic structure with an average particle size of only 10 nm. The reflection, excitation, and emission spectra were studied. The nanoparticles show blue shifted absorption bands with respect to coarse grained material.

For the first time Y2O3 has been deposited in the cubic equilibrium structure with a small particle size of 10 nm in a single processing step; the Figure shows the XRD patterns with Bragg peaks consistent with the structure. This communication shows that this good crystalline quality makes Y2O3 a promising host material for doped nanocrystalline phosphorus with high efficiency in lighting systems.

The BaO/W interaction is responsible for the emission properties of barium–oxide coated tungsten electrode coils in fluorescent lamps. The electronic structure of the BaO/W(001) interface is investigated by first-principles calculations within the local-density approximation of the density functional theory using the full-potential linearized augmented plane wave method. Results are presented for the total density of states (DOS), the atom- and orbital-resolved partial DOS and charge density distributions. Partial covalent character in the W–O and W–Ba bonding is shown. The main contribution to chemical bonding is caused by the tungsten d states and the adsorbate valence states, which interestingly also involve barium d states. This leads to a stabilization of the adsorbed configuration, with respect to cathode operation temperatures. The calculated work function is in agreement with experimental data.

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