IOSR-JAP   Volume-9 ~ Issue-6 ~ Nov-Dec 2017

ABSTRACT: In this article, we present a new technique to measure the static dielectric constant which was developed using atomic force microscopy (AFM) system. This technique is polarizability that is produced due to a low-frequency electric field. In addition, it is due to both permanent dipoles in the material and induced dipoles. Our goal was to show some physical, measurable quantity by Atomic Force Microscopy that can be related to the dielectric constant and our method was tested on a material whose dielectric constant is known such as strontium titanate and mica. The advantage of this method is that it does not require using the complex simulations that depend on the geometry of probe tip which is complicated and difficult to characterize.

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ABSTRACT: A novel zinc (metal) doped L-Lysine monohydrochloride (LMHCl) semiorganic crystal was grown by slow evaporation technique under isothermal condition. Single crystal X-ray diffraction analysis reveals that the crystal belongs to monoclinic system. The crystalline nature of the grown crystal was confirmed by powder X-ray diffraction analysis and the major peaks were indexed. FT-IR vibrational spectral study was used to identify the functional groups present in the grown crystal. The presence of zinc in the grown crystal was confirmed by inductively coupled plasma (ICP) elemental analysis. The density measurements were carried out by both theoretical and experimental methods........

Keywords: Crystal growth, FT-IR, Nonlinear Optical Material, Semiorganic, X-ray diffraction,

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ABSTRACT: Gel polymer electrolytes (GPE) are intended to help ion transportation in an enormously thick medium and consume incident light more efficiently in dye-sensitized solar cells. GPEs were synthesized by the addition of acetamide in poly (ethylene oxide) (PEO) and poly (ethylene glycol) dimethyl ether (PEGDME) with LiI/I2. PEO/PEGDME with 20 wt% acetamide provide highest efficiency (η = 4.89%) under 100 mW cm-2 illumination and exhibits highest ionic conductivity (σ = 1.47×10-3 S/cm) among the all electrolytes, compared to GPE without acetamide (η = 3.04%). The gain in open circuit voltage (Voc) was observed for GPEs due to the decrease in the recombination effect and electron lifetime increases by the addition of acetamide on the PEO. The short circuit current density (Jsc) is increased due to the growth in the ionic conductivity and amorphous nature of the GPE increases by addition of acetamide on the PEO.

Keywords: Dye sensitized solar cells (DSSC), Gel polymer electrolytes (GPE), poly (ethylene oxide) (PEO), Electrochemical Impedance Spectroscopy (EIS).

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ABSTRACT: Nanocrystalline Eu3+, Ho3+ co-doped Y2O3 powders with a maximum size of 9.8 nm were prepared by the sol-combustion process, using Y (NO3).6HO2 as an oxidizer, europium and holonium nitrates as activators, thiourea as a fuel and ethanol as a solvent. The crystal structure and optical properties were investigated by X-ray diffraction (XRD) patterns, Scanning electron microscope (SEM), equipped with energy dispersive X-ray (EDX), Ultra-violet visible (UV-Vis) spectroscopy, and Photoluminescence (PL). As Holonium concentration (x) varies from x = 0.1 to 0.5, the Y2O3:Eu3+:Ho3+ nanopowder exhibits a body – centred cubic structure of Y2O3 without any significant formation of a separated EuO2, or Ho2O3 phase. UV-Vis reveals that the optical band gap of Y2O3:Eu3+:Ho3+x alloys show red shift with increase............

Keywords: Y2O3:Eu3+: Ho3+x, band gap, sol-combustion, narrow emission, Fermi level

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