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101.
U.P. Verma Sonu Sharma Nisha Devi P. Rajaram 《Journal of magnetism and magnetic materials》2012,324(19):3017-3023
We have investigated the structural, electronic, magnetic and optical properties of Hg1?xMnxTe in the zinc-blende phase for 0≤x≤1. The calculations were performed by using the full potential linearized augmented plane wave plus local orbitals method within the framework of the density functional theory. The lattice constants of Hg1?xMnxTe at different Mn concentrations exhibit Vegard's law perfectly. For spin-up channel the Mn 3d bands are occupied and mixed with the Te 5p bands whereas for spin-down channel the Mn 3d bands are unoccupied. The values of the p–d exchange splitting energy, ?x(pd) as produced by the Mn 3d states are given. The contribution of the valence band and the conduction band in the process of exchange and splitting is described by the exchange coupling constants N0α and N0β. Due to p–d hybridization the magnetic moment of the Mn atom reduces, which results in small local magnetic moments on the non-magnetic Hg and Te sites. The potential applications of Hg1?xMnxTe in infrared device have been discussed on the basis of its optical properties. 相似文献
102.
Poonam Sharma D. K. Kanchan Nirali Gondaliya Meenakshi Pant Manish S. Jayswal 《Ionics》2013,19(2):301-307
In this paper, the electrical conductivity and relaxation studies in two different temperature regions (T?<?T m and T?>?T m) on plasticized PEO–PMMA blend polymer electrolyte system with AgNO3 salt are reported. The polymer electrolyte system has been prepared by solution cast technique and characterized by X-ray diffraction and differential scanning calorimetry. The conduction and relaxation processes at various temperatures have been investigated in the framework of modulus formalism. The distribution of relaxation times is discussed using Argand plot. Variation in ionic conductivity of polymer blends is discussed with the increase of PEO as well as with temperature. 相似文献
103.
M. Kameswara Rao M. Sharma S. K. Raza D. K. Jaiswal 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):559-566
The synthetic standards for cysteine and valine adducts of sulphur mustard have been synthesized using 2-(2-chloroethylthio) ethanol (half-mustard). These adducts have been recognized as biomarkers for exposure to sulphur mustard. The adducts have been fully characterized using 1 H and 13 C NMR spectroscopy and mass spectrometric techniques. 相似文献
104.
Arvind Samariya S.N. Dolia Arun S. Prasad P.K. Sharma S.P. Pareek M.S. Dhawan Sudhish Kumar 《Current Applied Physics》2013,13(5):830-835
CaFe2O4 nanocrystalline powders were synthesized through sol–gel treatment in which the stoichiometric mixing of various nitrates involving calcium and iron in presence of citric acid was performed. Subsequently, the as prepared sample was annealed at various temperatures in order to obtain the fine distribution of size including the bulk counterpart. The samples were then characterized using powder X-ray diffraction followed by 57Fe Mössbauer spectroscopy, SQUID as well as vibrating sample magnetometry. The results of spectroanalyses revealed that the samples were formed in single phase cubic spinel structure and exhibits room temperature superparamagnetism, except the bulk one, which crystallizes in characteristic orthorhombic structure of CaFe2O4 and displays trivial coercivity and remanent magnetization at room temperature. 相似文献
105.
Pooja Singla Manoj Sharma O. P. Pandey K. Singh 《Applied Physics A: Materials Science & Processing》2014,116(1):371-378
Undoped and Zn-doped TiO2 nanoparticles were synthesized by the sol gel method. The dopant (Zn) was taken at 0.1, 0.2, 0.5, 0.7, and 1.0 mol%. The initial precursors were titanium tetraisopropoxide and zinc acetate. The samples were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and UV–vis diffuse reflectance. The photocatalytic activity of the prepared nanoparticles was studied by observing their role in degradation of two azo dyes, i.e., Eriochrome Black T and Methyl Red under UV–visible light. The results revealed that Zn-doped TiO2 nanoparticles exhibited better degradation as compared to undoped TiO2 nanoparticles. In this study, 0.7 mol% Zn-doped TiO2 showed highest photocatalytic activity. Doping of Zn allowed better separation of electron–hole pairs which results in increased oxidation and reduction reactions. 相似文献
106.
Surya Prakash Singh CH Pavan Kumar G. D. Sharma J. A. Mikroyannidis Manjeet Singh Rajnish Kurchania 《Journal of Polymer Science.Polymer Physics》2012,50(23):1612-1618
Power conversion efficiency (PCE) of phenylenevinylene‐based copolymer with BF2 azopyrrole complex (PB)/modified PC70BM, that is, CN‐PC70BM bulk heterojunction solar cells improves from 2.16 to 4.90% using a processing additive and drying condition. The results demonstrate that a processing additive and drying condition provides an effective means to control both the surface roughness and finer interpenetrating networks to enhance the exciton dissociation into free charge carriers, charge transportation, and collection. Taking into the account of simple device fabrication process without thermal annealing, the PCE of the polymer solar cell can further improved by chloronapthalene (CN) additive under the fast drying condition. The average carrier lifetimes extracted from the impedance spectra and found to correlate with measured PCEs. At short circuit conditions and illumination, the average charge carrier lifetime was found vary from 16.8 to 32 μs with power conversion efficiencies ranging from 3.0 to 4.9%. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献
107.
A Facile and Convenient Method for the Synthesis of 8-Methoxy 10,11-Dihydronaphtho [1,2-b]Quinolines
Dihydronaphthoquinolines are relatively rare polycyclic heterocyclic compounds. We wish to report a simple and convenient preparative method for hitherto unknown compounds with these new structural features. 6-methoxy tetralone1 (I) 3.5g (.02 mole) in 3 ml DMF was added slowly to 4.6g (.02 mole) of POCl3 in 3ml DMF at 0°C. The mixture was stirred for 5 hrs. and the temp. was then gradually raised from 0° to 60–65°C. The resultant complex was treated with aq. sodium acetate solution till pH5–6 was reached. The extract on usual purification, furnished 3.2g (80°%.) of 1-chloro, 6-methoxy, 1,2,3,4 tetrahydro naphthalene-2-aldehyde(II)+2 相似文献
108.
A simple and efficient synthesis of nickel(II) 2‐benzazolo‐5,10,15,20‐tetraphenylporphyrins from nickel(II) 2‐formyl‐5,10,15,20‐tetraphenylporphyrin and o‐arylenediamines, o‐aminophenols or o‐aminothiophenol in 1,2‐dichlorobenzene is described. A diverse range of novel β‐substituted azoloporphyrins has been successfully synthesized in good yields and their structures are confirmed on the basis of spectral data. J. Heterocyclic Chem., (2012). 相似文献
109.
Harshal P. Mungse Niharika Bhakuni Deependra Tripathi Om P. Sharma Bir Sain Om P. Khatri 《Journal of Physical Organic Chemistry》2014,27(12):944-951
Graphene oxide (GrO) prepared by the Hummers method was separated into three different fractions (GrO5000, GrO2000, and GrOres) on the basis of their dispersion stability in the water. Infrared, nuclear magnetic resonance, X‐ray photoelectron spectroscopy, and elemental analyses revealed that GrO5000 possesses a high degree of oxygen functionalities including phenolic, carboxylic, and ?OSO2H groups, compared with the other fractions. The GrO5000 was found to be a highly efficient and reusable solid catalyst for the esterification of various carboxylic acids with a variety of alcohols to furnish corresponding esters in high to excellent yields. The catalytic activity of the GrO5000 was attributed to the ability of highly polar GrO5000 scaffold to adsorb/attract reactants, where the acid functionalities of GrO5000 facilitated the esterification process efficiently. The chemical and structural features of GrO5000 were discussed to understand the improved catalytic activity compared with GrO2000 and conventional solid acid catalysts. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
110.
Sanjeev K. Sharma Sungeun Heo Byoungho LeeHwangho Lee Changmin KimDeuk Young Kim 《Current Applied Physics》2014,14(12):1696-1702
We report on an n-ZnO/p-GaN heterojunction diode fabricated from zinc oxide (ZnO) films at various growth temperatures (450, 500, 550, and 600 °C) by RF sputtering. The films were subsequently annealed at 700 °C in N2 ambient. To investigate the influence of the growth temperature of n-ZnO films, the microstructural, optical, and electrical properties were measured using scanning electron microscopy (SEM), X-ray diffraction (XRD), photoluminescence (PL), and Hall measurements. The XRD pattern showed the preferred orientation along the c-axis (002) regardless of growth temperature. The PL spectra showed a dominant sharp near-band-edge (NBE) emission. Current–voltage (I–V) curves showed excellent rectification behavior. The turn-on voltage of the diode was observed to be 3.2 V for the films produced at 500 °C. The ideality factor of ZnO film was observed to be 1.37, which showed the best performance of the diode. 相似文献