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Glass samples with composition (50 - X) PbO - (25 + X) TiO2 - 25 B2O3 (where X =0, 5, 10 and 12.5 mol %) were prepared using conventional quenching technique. These glass samples were converted to glass ceramics by following two stage heat treatment schedules. Transition temperature (Tg), crystallization temperature (Tc), density and Coefficient of Thermal Expansion (CTE) of glass and glass ceramic samples measured. Tg and Tc observed to decrease with increase in the content of TiO2. The density values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and CTE results of the glass–ceramics. The dielectric constant of glass ceramic samples is higher than those of corresponding glasses. Maxwell’s dielectric mixture formula was used to correlate the theoretically predicted values of dielectric constant with experimentally observed values. [ABSTRACT FROM AUTHOR]

In this article, we report advancement in structural, morphological and dielectric studies of PVA encapsulated titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles. PVA/(x)TiO2(15-x)ZnO nanocomposites are prepared using solvent casting ex-situ technique for x= 0wt%, 1wt%, 5wt%, 7.5wt%, 10wt%, 14wt% and 15wt% filling concentrations. FTIR spectroscopy reveals the formulation of complexes between the PVA main chain and nano fillers is due to inter/intra molecular hydrogen bonding. The AFM picture shows the uniform grain structure for pure PVA and changes in surface morphology for prepared PVA nanocomposites. The morphological and homogeneous distribution of nano fillers in PVA nanocomposites was observed using SEM and EDAX. AC conductivity studies spectacles that the conductivity increases for different filling concentrations with increase in frequency. The frequency dependent dielectric constants with different filling concentrations are recorded. [ABSTRACT FROM AUTHOR]

Spacers are a key component of the gas-insulated structures. Most dielectric instances intensity collapses and ground flashover are attributed to distinguish the failures of spacer. Such Failures are due to non-uniformity distribution of electric field around the top of the spacer and high field tension at triple junctions. For a better electric field distribution, precise structure simulation of the spacers is important as it improves the component's existence. Rare pressure management results in problems such as moulding and manufacturing by shape modeling. In this paper, a graded high FGM insulating spacer is designed for a Single phase GIS for reduction of electric field stress. Stress in the electrical field for different values of high grading the FGM material is measured and the insertion of metal inserts is used to reduce the electrical field pressure. [ABSTRACT FROM AUTHOR]

The Sr2+ substituted 0.5(BiFeO3)-0.5(Ba0.90Sr0.10TiO3) ceramic has been synthesized by a conventional solid state reaction method. The structural analysis was carried out by room temperature x-ray diffraction and Raman spectra. The study reveals stabilization of tetragonal phase with P4mm space group. The coexistence of ferroelectric transition (TC = 270°C) and diffuse frequency independent dielectric anomaly at TN∼ 445°C were observed in temperature dependent dielectric studies. The simultaneous enhancement in ferroelectric polarization (Ps)∼9.4 µC/cm2 and magnetization Ms∼2.8 emu/g, at room temperature was observed, which indicates BFBST is a good multiferroic material for future spintronic device applications. [ABSTRACT FROM AUTHOR]

The dielectric and impedance spectroscopic properties of NiFe1.95R0.05O4 (R = Y, Yb and Lu) were investigated. The materials were prepared by solid state reaction and crystallized in the cubic inverse spinel phase with a very small amount additional phase of RFeO3 (R = Y, Yb and Lu) as secondary phase. The scanning electron micrograph images clearly show grains (∼2μm) which are separated by thin grain boundaries. The presences of all elements were confirmed by the energy dispersive X-ray elemental mapping. The frequency variation of ε’ shows the dispersion, following the Koop’s phenomenological theory, which considers the dielectric structure as an inhomogeneous medium of two-layers of the Maxwell-Wagner type. Impedance spectroscopic analysis indicates the different relaxation mechanisms, which corresponds to bulk grain and grain-boundaries. Their contributions to the electrical conductivity and capacitance of these materials were discussed in detailed. [ABSTRACT FROM AUTHOR]