02200nas a2200229   4500008004100000022001400041245009100055210006900146260007300215300001400288490000700302520140100309653001401710653001501724653001901739653002201758653000801780100002401788700001901812700002201831856011701853       2008                        eng d  a0039-914000aControlled synthesis of ZnO from nanospheres to micro-rods and its gas sensing studies0 aControlled synthesis of ZnO from nanospheres to microrods and it  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN  a1315-13190 v753 a<p>1D ZnO rods are synthesized using less explored hydrazine method. Here we find, besides being combustible hydrazine can also be used as a structure-directing agent. The ratio of zinc nitrate (ZN) to hydrazine is found to control the morphology of ZnO. At lower concentration of ZN as compared with hydrazine the morphology of ZnO is found to be spherical. As we increase the hydrazine content the morphology changes from spherical (diameter similar to 100 nm) to the elongated structures including shapes like Y, T as well dumbbell (diameter similar to 40 nm and length similar to 150 nm). Interestingly for more than 50% of hydrazine ZnO micro-rods are formed. Such rods are of diameter similar to 120 mn having length of about 1 mu m for ZN to hydrazine ratio of 1:9, isolated as well as bundle of rods are seen in scanning electron microscopy (SEM). The X-ray diffraction (XRD) reveals the phase formation with average particle size of 37 nm as calculated using Scherrer's formula. The high-resolution transmission electron microscopy (HRTEM) is also done to confirm the d-spacing in ZnO. Gas sensing study for these samples shows high efficiency and selectivity towards LPG at all operating temperatures. Photoluminescence (PL) study for these samples is performed at room temperature to find potential application as photoelectric material. (C) 2008 Elsevier B.V. All rights reserved.</p>10aHydrazine10aLPG sensor10aNanostructures10aphotoluminescence10aZnO1 aNavale, Shalaka, C.1 aGosavi, S., W.1 aMulla, Imtiaz, S.  uhttps://library.ncl.res.in/content/controlled-synthesis-zno-nanospheres-micro-rods-and-its-gas-sensing-studies-002342nas a2200265   4500008004100000022001400041245006100055210006000116260009200176300001200268490000600280520146300286653001901749653002601768653001901794653000801813100002401821700002601845700002201871700002201893700002001915700002301935700002301958856009501981       2009                        eng d  a1662-525000aField emission properties of Al-doped ZnO nanostructures0 aField emission properties of Aldoped ZnO nanostructures  aLAUBISRUTISTR 24, STAFA-ZUERICH, CH-8712, SWITZERLANDbTRANS TECH PUBLICATIONS LTDcJAN  a231-2370 v53 a<p>Field emission from Al-doped ZnO nanostrcutures has been investigated in planar diode configuration under ultra high vacuum conditions. The Al-doped ZnO nanostructures were synthesized by co-precipitation method with varying aluminium concentrations. The as- synthesized product was characterized by x-ray diffraction, scanning electron microscope and energy dispersive x-ray analysis. The threshold field required to draw a current density of similar to 1 mu A/cm(2) was observed to be similar to 2.0 V/mu m and similar to 2.3 V/mu m for Al-doped ZnO nanostructures synthesized with aluminium concentrations of 1% and 3%, respectively. The Fowler- Nordheim (F-N) plots for both the specimens exhibit non-linear behaviour, which is observed to be specimen dependent. The nonlinearity observed in the F-N plots has been interpreted on the basis of the theory of electron emission from semiconductor emitters. The field enhancement factors, estimated from the slope of the F-N plots, are found to be similar to 9.3 x 10(3) and 3.9 x 10(3) for 1% and 3% Al-doped ZnO emitters, respectively. The high values of the field enhancement factor Suggest that the emission is from the nanostructures. The emission current stability measured at the preset value of similar to 2 mu A over a period of more than three hours is found to be fairly stable. The results indicate use of Al-doped ZnO nanostructures as promising emitters for field emission based devices.</p>10afield emission10aFowler-Nordheim plots10aNanostructures10aZnO1 aNavale, Shalaka, C.1 aSheini, Farid, Jamali1 aPatil, Sandip, S.1 aMulla, Imtiaz, S.1 aJoag, Dilip, S.1 aMore, Mahendra, A.1 aGosavi, Suresh, W.  uhttps://library.ncl.res.in/content/field-emission-properties-al-doped-zno-nanostructures-001941nas a2200229   4500008004100000022001400041245008400055210006900139260010600208300001400314490000700328520108600335653002301421653002601444653001901470653001101489653002201500100002501522700002401547700002201571856011801593       2009                        eng d  a0025-540800aMicrowave-assisted synthesis and humidity sensing of nanostructured alpha-Fe2O30 aMicrowaveassisted synthesis and humidity sensing of nanostructur  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAY  a1179-11820 v443 a<p>Nanocrystalline alpha-Fe2O3 has been prepared on a large-scale by a facile microwave-assisted hydrothermal route from a solution of Fe(NO3)(3)center dot 9H(2)O and pentaerythritol. A systematic study of the morphology, crystallinity and oxidation state of Fe using different characterization techniques. Such as transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy was performed It reveals. that nanostructured alpha-Fe2O3 comprises bundles of nanorods with a rhombohedral crystalline Structure. The individual nanorod has 8-10 nm diameter and similar to 50 nm length. The as-prepared nanostructured alpha-Fe2O3 (sensor) gives selective response towards humidity. The sensor shows high sensitivity, fast linear response to change in the humidity with almost 100% reproducibility. The sensor works at room temperature and rejuvenates without heat treatment. The as-prepared nanostructured alpha-Fe2O3 appears to be a promising humidity sensing material with the potential for commercialization. (C) 2008 Elsevier Ltd. All rights reserved.</p>10aChemical synthesis10aElectrical properties10aNanostructures10aOxides10aX-ray diffraction1 aDeshmukh, Rupali, G.1 aBadadhe, Satish, S.1 aMulla, Imtiaz, S.  uhttps://library.ncl.res.in/content/microwave-assisted-synthesis-and-humidity-sensing-nanostructured-alpha-fe2o3-001602nas a2200253   4500008004100000022001400041245010500055210006900160260007100229300001400300490000600314520069700320653001901017653002501036653001901061653001701080653000801097100002601105700002301131700002001154700002201174700003001196856012201226       2010                        eng d  a1936-085100aFowler-nordheim plot behavior and mechanism of field electron emission from ZnO tetrapod structures	0 aFowlernordheim plot behavior and mechanism of field electron emi  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT  a5585-55900 v43 a<p>Field emission measurements of current-voltage characteristics are reported for tetrapod structures of ZnO. The nonlinear Fowler-Nordheim (FN) plot is analyzed according to a model of calculation based on saturation of conduction band current and predominance of valence band current at high-field values. The simulated FN plot exhibits similar features to those observed experimentally. The model of calculation suggests that the slope variation of the FN plot, in the high-field and low-field regions, does not depend on the magnitude of saturation. Instead, it is a characteristic of the energy band structure and voltage-to-barrier-field conversion factor of the emitting material.</p>10afield emission10aFowler-Nordheim plot10aNanostructures10anonlinearity10aZnO1 aAl-Tabbakh, Ahmed, A.1 aMore, Mahendra, A.1 aJoag, Dilip, S.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/fowler-nordheim-plot-behavior-and-mechanism-field-electron-emission-zno-tetrapod-001919nas a2200217   4500008004100000022001400041245008900055210006900144260006900213300001200282490000800294520115200302653001101454653001201465653001501477653002601492653001901518100002501537700002201562856011701584       2010                        eng d  a0254-058400aInfluence of palladium on gas-sensing performance of magnesium ferrite nanoparticles0 aInfluence of palladium on gassensing performance of magnesium fe  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcJAN  a319-3230 v1193 a<p>Commercial ferrites with high densities are mostly used in the electromagnetic devices, which require high temperature synthesis. In this article the gas-sensing characteristics of pure and Pd-doped MgFe(2)O(4) powder has been discussed. The synthesis has been carried out by using a simple molten salt method. This method facilitates rapid synthesis at comparatively lower temperature enabling formation of nanostructures, suitable for the gas-sensing application. Various physicochemical techniques have been used for the characterization of samples. X-ray diffraction analysis confirmed the single-phase formation of pure and Pd-doped MgFe(2)O(4) having crystallite size 15-20 nm. Pure MgFe(2)O(4) showed highest responses towards liquid petroleum gas (LPG) at 350 degrees C while, on doping with Pd the highest response shifted towards lower operating temperature of similar to 200 degrees C. Pure MgFe(2)O(4) exhibited some response towards 200 ppm of LPG which markedly increased on doping of palladium (Pd). The probable mechanism is proposed to explain the selective response towards LPG. (C) 2009 Elsevier B.V. All rights reserved.</p>10aDoping10aFerrite10aLPG sensor10aMolten salt synthesis10aNanostructures1 aDarshane, Sonali, L.1 aMulla, Imtiaz, S.  uhttps://library.ncl.res.in/content/influence-palladium-gas-sensing-performance-magnesium-ferrite-nanoparticles-001991nas a2200229   4500008004100000022001400041245011500055210006900170260010600239300001200345490000700357520109500364653002501459653001201484653001901496653002301515653001801538100002801556700002201584700002501606856013001631       2011                        eng d  a0025-540800aLow temperature pH dependent synthesis of flower-like ZnO nanostructures with enhanced photocatalytic activity0 aLow temperature pH dependent synthesis of flowerlike ZnO nanostr  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAY  a771-7780 v463 a<p>In the present study we have synthesized flower-like ZnO nanostructures comprising of nanobelts of 20 nm width by template and surfactant free low-temperature (4 degrees C) aqueous solution route. The ZnO nanostructures exhibit flower-like morphology, having crystalline hexagonal wurtzite structure with (001) orientation. The flowers with size between 600 and 700 nm consist of ZnO units having crystallite size of similar to 40 nm. Chemical and structural characterization reveals a significant role of precursor: ligand molar ratio, pH, and temperature in the formation of single-step flower-like ZnO at low temperature. Plausible growth mechanism for the formation of flower-like structure has been discussed in detail. Photoluminescence studies confirm formation of ZnO with the defects in crystal structure. The flower-like ZnO nanostructures exhibit enhanced photochemical degradation of methylene blue (MB) with the increased concentration of ligand, indicating attribution of structural features in the photocatalytic properties. (C) 2010 Elsevier Ltd. All rights reserved.</p>10aCatalytic properties10aDefects10aNanostructures10aOptical properties10aSemiconductor1 aVaishampayan, Mukta, V.1 aMulla, Imtiaz, S.1 aJoshi, Satyawati, S.  uhttps://library.ncl.res.in/content/low-temperature-ph-dependent-synthesis-flower-zno-nanostructures-enhanced-photocatalytic-0