Optical analysis of samarium doped sodium bismuth silicate glass

Samarium doped sodium bismuth silicate glass was synthesized using the melt quenching method. Detailed optical spectroscopic studies of the glassy material were carried out in the UV–Vis-NIR spectral range. Using the optical absorption spectra Judd-Ofelt (JO) parameters are derived. The calculated values of the JO parameters are utilized in evaluating the various radiative parameters such as electric dipole line strengths (Sed), radiative transition probabilities (Arad), radiative lifetimes (τrad), fluorescence branching ratios (β) and the integrated absorption cross- sections (σa) for stimulated emission from various excited states of Sm3 +‡ ion. The principal fluorescence transitions are identified by recording the fluorescence spectrum. Our analysis revealed that the novel glassy system has the optimum values for the key parameters viz. spectroscopic quality factor, optical gain, stimulated emission cross section and quantum efficiency, which are required for a high performance optical amplifier. Calculated chromaticity co-ordinates (0.61, 0.38) also confirm its application potential in display devices

Growth and characterization of Sm3+ doped cerium oxalate single crystals

Single crystals of Sm3+ doped cerium oxalate decahydrate were synthesized using single diffusion gel technique and the conditions influencing the size, morphology, nucleation density and quality of the crystals were optimized. Highly transparent single crystals of average size 3 mm × 2 mm × 1 mm with well-defined hexagonal morphology were grown during a time period of two weeks. X-ray powder diffraction analysis revealed that the grown crystals crystallize in the monoclinic system with space group P21/c as identical with the pure cerium oxalate. The various functional groups of the oxalate ligand and the water of crystallization were identified by Fourier transform infrared spectroscopy. The photoluminescence spectrum of the Sm3+ doped cerium oxalate indicated that the Sm3+ ions are optically active in the cerium oxalate matrix. The crystal has a strong and efficient orange red emission with a wavelength peak at 595 nm and hence can be effectively used for optical amplification. Microhardness measurements of the crystal revealed that they belong to the soft material category

Development and characterizations of Ag nanoparticles decorated TiO2-ZrO2 coatings as electrode material for supercapacitors

Supercapacitors are considered as newly developed auxiliary and clean supplies of power and energy for the next generation energy storage devices with significant impact in many fields. In the present investigation, Ag nanoparticles decorated over TiO2-ZrO2 films are used as the material for energy storage applications. The cyclic voltammograms of the proposed material show better specific capacitance values and robust cyclic stability. The results of the electrochemical measurements further show a strong double-layer electrical capacitance of ternary mixed oxides. The synergetic interaction among the components in the hierarchical nanostructured porous Ag@TiO 2-ZrO2 film guaranteed the good capacitive performance. The comparison between the TiO2-ZrO2 films and Ag decorated TiO 2-ZrO2 films bring out the strong interconnection between the constitution and composition of both systems and their properties. These results underline the exceptional electrical double layer capacitive behavior that is seen in porous ternary composite films with better surface area. Furthermore, such a simple and low-cost layer by layer assembly method with self-cleaning property can be used for the large-scale fabrication of diverse functional architectures for energy storage and conversions

NIR emission studies and dielectric properties of Er(3+)-doped multicomponent tellurite glasses.

Multicomponent tellurite glasses containing altered concentrations of Er2O3 (ranging from 0 to 1 mol%) were prepared by the standard melt quenching technique. Investigations through energy dispersive X-ray spectroscopy (EDS), Raman scattering spectroscopy, Fourier transform infrared (FTIR) spectroscopy, near-infrared (NIR) emission studies and dielectric measurement techniques were done to probe their compositional, structural, spectroscopic and dielectric characteristics. The broad emission together with the high values of the effective linewidth (~ 63 nm), stimulated emission cross-section (9.67 × 10− 21 cm2) and lifetime (2.56 ms) of 4I13/2 level for 0.5 mol% of Er3+ makes these glasses attractive for broadband amplifiers. From the measured capacitance and dissipation factor, the relative permittivity, dielectric loss and the conductivity were computed; which furnish the dielectric nature of the multicomponent tellurite glasses that depend on the applied frequency. Assuming the ideal Debye behavior as substantiated by Cole–Cole plot, an examination of the real and imaginary parts of impedance was performed. The power–law and Cole–Cole parameters were resolved for all the glass samples. From the assessment of the emission analysis and dielectric properties of the glass samples, it was obvious that the Er3+ ion concentration had played a vital role in tuning the optical and dielectric properties and the 0.5 mol% of Er3+ -doped glass was confirmed as the optimum composition