The resistivity and magnetization of layered perovskite La222xCa112xMn2O7 have been studied systematically using bulk samples with a wide doping concentration range 0<x<0.5 and epitaxial thin film samples with x50.3. The system becomes a metallic ferromagnet for doping concentrations 0.22<x<0.5. In this doping region, results for bulk samples as well as for thin films have clearly shown that th...

The hole-concentration (x) dependence of the three-dimensional energy-momentum dispersion in (Bi, Pb)2(Sr, La)2CuO(6+delta) has been investigated by angle-resolved photoemission spectroscopy. For a heavily overdoped sample of T(c) < or = 0.5 K, an energy dispersion of approximately 10 meV in width is observed in the vicinity of the (pi, 0) point with varying momentum along the c axis (k(z)). Th...

The chemical selectivity and great sensitivity of the Extended X-ray Absorption Spectroscopy technique allowed the determination, in the paramagnetic phase, of the structural distortions induced by doping in the spin-Peierls CuGeO3 compound. The distorted environments were analyzed as a function of concentration, magnetic nature of impurity and the substitution site (Ni, Mn and Zn impurities on...

Si nanocrystals embedded in SiO2 doped with P and Au at concentrations in the range of 1 10–3 10 cm 3 exhibit photoluminescence quenching. Upon increasing the Au concentration, a gradual decrease in nanocrystal photoluminescence intensity is observed. Using a statistical model for luminescence quenching, we derive a typical radius of 3 nm for nanocrystals luminescing around 800 nm. Au doping al...

Cobalt (Co) doped Zinc Oxide (ZnO) thin films, containing different amountof Cobalt nanoparticles as the Co doping source, deposited by the sol–gel spin coatingmethod onto glass via annealing temperature at 400˚C, have been investigated by opticalcharacterization method. The effect of Co incorporation on the surface morphology wasclearly observed from scanning electron microscopy (SEM) images. ...

Silica based waveguides on Si fabricated by flame hydrolysis deposition were doped with erbium ions using an aerosol doping technique, and co-doped with GeO2, P2O5 and B2O3. Erbium doping levels in the films were dependent on the nebulized solution concentration and delivery rate of the aerosol to the torch. The erbium solution concentration was varied from 4 to 8 wt%. The refractive index was ...

High-conductive phosphorus-doped Si nanocrystals/SiO2(nc-Si/SiO2) multilayers are obtained, and the formation of Si nanocrystals with the average crystal size of 6 nm is confirmed by high-resolution transmission electron microscopy and Raman spectra. The temperature-dependent carrier transport behaviors of the nc-Si/SiO2 films are systematically studied by which we find the shift of Fermi level...