Structural, morphological, dielectric and optical properties of double perovskites RBaFeTiO6 (R = La, Eu).

Double perovskites RBaFeTiO6 (R = La, Eu) were successfully synthesized using a solid state reaction route. Structural refinement analysis has been performed to investigate the details of the crystalline structure which was found to be a cubic double perovskite structure at room temperature (space group Pm3̄m, No. 221). Crystallite size, lattice strain, density, and porosity parameters were also calculated. The morphology and the elemental composition were analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and elemental mapping. FTIR and Raman scattering spectroscopy have been performed in order to study the vibrational modes and the various bond formations of the synthesized samples. The optical properties investigated by means of the optical absorbance measurements highlight that both materials present large band gap energies, and are thus potential candidates for various technological applications. The electrical behavior of these double perovskites was also studied by frequency-dependent dielectric measurements and impedance spectroscopy. The electrical conduction follows Jonscher's power law and the conduction mechanisms are identified.

Optical Properties of Ag-TiO(2) Nanocermet Films Prepared by Cosputtering and Multilayer Deposition Techniques.

Ag-TiO(2) nanocermet thin films, deposited for optical filtering applications by two sputtering techniques, codeposition and multilayer deposition, exhibit surface plasmon absorption in the spectral range 450-500 nm. The cosputtering technique induces a columnar growth, whereas multilayer deposition produces a more-random distribution of silver inclusions. Both films have large, flat silver grains at the air-cermet interface. An optical double-heterogeneous layer model based on the experimental morphological parameters of the films accounts well for their experimental transmittance, notably for extra absorption near 700 nm, which is attributed to a surface plasmon in the flat silver grains of the surface.

Optical properties of Ag -TiO 2 nanocermet films prepared by cosputtering and multilayer deposition techniques.

Ag -TiO2 nanocermet thin films, deposited for optical filtering applications by two sputtering techniques, codeposition and multilayer deposition, exhibit surface plasmon absorption in the spectral range 450 -500 nm. The cosputtering technique induces a columnar growth, whereas multilayer deposition produces a more-random distribution of silver inclusions. Both films have large, flat silver grains at the air -cermet interface. An optical double-heterogeneous layer model based on the experimental morphological parameters of the films accounts well for their experimental transmittance, notably for extra absorption near 700 nm, which is attributed to a surface plasmon in the flat silver grains of the surface.