Sintered (1475 °C/2 h) pellets of Ba(Zn1/3Ta2/3)O3 were annealed at temperatures ranging from 1550 to 1625 °C/15 h and subsequently quenched into water. The degree of B-site order between the Zn and Ta cations was investigated using x-ray diffraction (XRD) and transmission electron microscopy (TEM). Samples quenched from 1575 to 1600 °C exhibit the highest degree of order by XRD. Dark-field TEM images from these samples revealed 1:2, Zn:Ta, trigonal, ordered domains approximately 0.4 μm diam near grain boundaries but 100 nm in the grain interior. Samples annealed and quenched from 1625 °C exhibited no ordered superlattice reflections by XRD. However, diffuse scatter along 〈111〉 directions and fcc rather than trigonal ordered reflections were observed in electron diffraction patterns. Disordered samples were subsequently annealed at 1500 °C/15 h (below the order–disorder phase transition ∼1625 °C) and ±13{hkl} superlattice reflections reappeared in XRD patterns demonstrating the reversibility of the phase transition.

A general method, which we call the potential S-matrix pole method, is developed for obtaining the S-matrix pole parameters for bound, virtual, and resonant states based on numerical solutions of the Schrödinger equation. This method is well known for bound states. In this work we generalize it for resonant and virtual states, although the corresponding solutions increase exponentially when r → ∞. Concrete calculations are performed for the 1 + ground state of 14 N, the resonance 15 F states (1/2 + , 5/2 + ), low-lying states of 11 Be and 11 N, and the subthreshold resonance in the proton-proton system. We also demonstrate that in the case of broad resonances, their energy and width can be found from the fitting the experimental phase shifts using the analytical expression for the elastic-scattering S matrix. We compare the S-matrix pole and the R matrix methods for broad resonances in the 14 O-p and in 26 Mg-n systems.A. M. MUKHAMEDZHANOV et al. PHYSICAL REVIEW C 81, 054314 (2010)

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In this investigation properties of organic semiconductor copper phthalocyanine (CuPc) capacitive humidity and illumination sensors were studied. Organic thin film was deposited by vacuum evaporation on a glass substrate with silver surface-type electrodes to form the Ag/CuPc/Ag sensor. The capacitance of the samples was evaluated at room temperature in the relative humidity range of 35-92%. It was observed that capacitance of the Ag/CuPc/Ag sensor increases with increase in humidity. The ratio of the relative capacitance to relative humidity was about 200. It is assumed that in general the capacitive response of the sensor is associated with polarization due to absorption of water molecules and transfer of charges (electrons and holes). It was observed that under filament lamp illumination of up to 1,000 lx the capacitance of the Ag/CuPc/Ag photo capacitive detectors increased continuously by 20% as compared to dark condition. It is assumed that photo capacitive response of the sensor is associated with polarization due to transfer of photo-generated electrons and holes. An equivalent circuit of the Ag/CuPc/Ag capacitive humidity and illumination sensor was developed. Humidity and illumination dependent capacitance properties of this sensor make it attractive for use in humidity and illumination multi-meters. The sensor may be used in instruments for environmental monitoring of humidity and illumination.

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An Ag2O(x)−PrO2(y)/γ-Al2O3 electrocatalyst series (X:Y is for Ag:Pr from 0 to 10) was synthesized, to use synthesized samples in electrochemical applications, a step in fuel cells advancements. Ag2O(x)−PrO2(y)/γ-Al2O3/Glassy-Carbon was investigated for electrochemical oxidation of ammonia in alkaline medium and proved to be highly effective, having high potential utility, as compared to commonly used Pt-based electrocatalysts. In this study, gamma alumina as catalytic support was synthesized via precipitation method, and stoichiometric wt/wt.% compositions of Ag2O−PrO2 were loaded on γ-Al2O3 by co-impregnation method. The desired phase of γ-Al2O3 and supported nanocatalysts was obtained after heat treatment at 800 and 600 °C, respectively. The successful loadings of Ag2O−PrO2 nanocatalysts on surface of γ-Al2O3 was determined by X-rays diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR), and energy dispersive analysis (EDX). The nano-sized domain of the sample powders sustained with particle sizes was calculated via XRD and scanning electron microscopy (SEM). The surface morphology and elemental compositions were examined by SEM, transmission electron microscopy (TEM) and EDX. The conductive and electron-transferring nature was investigated by cyclic voltammetry and electrochemical impedance (EIS). Cyclic voltammetric profiles were observed, and respective kinetic and thermodynamic parameters were calculated, which showed that these synthesized materials are potential catalysts for ammonia electro-oxidation. Ag2O(6)−PrO2(4)/γ-Al2O3 proved to be the most proficient catalyst among all the members of the series, having greater diffusion coefficient, heterogeneous rate constant and lesser Gibbs free energy for this system. The catalytic activity of these electrocatalysts is revealed from electrochemical studies which reflected their potentiality as electrode material in direct ammonia fuel cell technology for energy production.

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Ceramics-based capacitors with excellent energy storage characteristics, fast charging/discharge rate, and high efficiency have received significant attention. In this work, Na[Formula: see text]Bi[Formula: see text]NbO3(NBN) ceramics were processed through solid-state sintering route. The investigated ceramics were crystallized in a single perovskite phase. Dense microstructure, with small average grain size ([Formula: see text]0.92 [Formula: see text]m) is obtained for the investigated ceramics. A high dielectric constant >1000 accompanied by a low dielectric loss was achieved for these ceramics at ambient temperature. A recoverable energy density [Formula: see text]0.92 J/cm3and ultra-high efficiency of 96.33% at 138 kV/cm were obtained at room temperature. Furthermore, a lower discharging time of 0.14 [Formula: see text]s was also achieved. This material is a suitable candidate for power pulsed applications.