[en] Indium antimonide (lnSb) is one of the most widely used materials in the field of infrared detectors in the 35 μm wavelength range owing to its high electron mobility and low energy band gap 0.18 eV at room temperature. It is used for the fabrication of high speed Hall and optoelectronic devices. The n-type lndium antimonide thin films at different substrate temperature (50℃ - 70℃) has been fabricated by electron beam evaporation technique at pressure 10^-5 torr. The X-ray diffraction patterns reveal that films are polycrystalline nature with zinc blende structure and having orientation along (111) plane. The value of grain size for (111) is calculated. The particle size increases with the increase of substrate temperature. (author)

[en] Indium oxide thin films were prepared by pulsed dc magnetron sputtering technique with no substrate heating. X-ray diffraction was used to investigate the structural properties and AFM was used to study the surface morphology gas sensing performance were conducted using a static gas sensing system. Room temperature gas sensing performance was conducted in range of 17 to 286 ppm. The sensitivity, response and recovery time of the sensor was also determined. (author)

[en] In present work the nano-structured pure ZrO₂ thin films were prepared using spray pyrolysis techniques. The aqueous solution of ZrCl₄, was used as a precursor with flow rate controlled 5 mI/min. The films were synthesized on glass substrate between temperature 250-400℃ and subjected to different analytical characterization like SEM, XRD, TEM, FTIR, UV, TGA-DTA/DSC. The gas sensing performances of various gases were tested in different operating temperature range. The sensitivity, selectivity, response and recovery time for H₂S gas was discussed. Also nano structured grain size discussed. (author)

[en] A series of ZrO₂-SiO₂, nanosized mixed oxides has been fabricated using the chemical sol-gel procedure with four stages: prehydrolysis of TEOS, addition of Zr(OPr)₄, complete hydrolysis and gelation. The effect of annealing temperature and the ratio of Zr/Si on the structural properties of nanosized mixed oxides have been studied. The structure of samples has been investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The crystallite size of synthesized nanopowders has been determined by Debye-Scherer and Williamson-Hall equations, and compared. The structural parameters such as lattice constants, micro-strain and dislocation density have also been evaluated. The FTIR spectra throw light on the bonding pattern of the constituent atoms and groups such as Zr, Si, O and OH. The results suggest that crystallite size of nanosized samples increases with increasing temperature. (author)

[en] Nanocrystalline perovskites LaMnO₃ gas sensor has been developed with high sensitivity for ammonia gas by doping Cd. Nanocrystalline LaMnO₃ were prepared by the sol gel citrate. The structural characterization was studied by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM results show perovskite structures, with grain growth 30 nm. Nanostructured LaMnO₃, and La_1-xCd_xMnO₃ (x = 0, 0.1, 0.15) were studied. The operation temperature falls and sensitivity increases when Cd concentration in LaMnO₃, changes from x = 0 to x = 0.1. Ag impregnation over La_0.9Cd_0.1MnO₃ sensor, on exposure to ammonia at about 120℃ showed an increased sensitivity as well as the response time also decreases. The possible ammonia sensing mechanism is proposed. (author)

[en] Nanoscience and nanotechnology has made great strides in the development of core technology in the 21st century. It is the branch of science and technology that deals with the things on nanometric scale. It is well established that the properties of materials at this scale are entirely different from those at the bulk level; fullerenes are known to be superconducting, carbon nanotubes have optical, electrical and mechanical behaviour entirely different from those in bulk materials. The physics of Quantum Dots open some new aspects of physics. The subject is so exciting and versatile that it has made inroads in all branches of science. One talks of nanoelectronics, nanophotonics, nanobiotechnology, nanomedicine, nanorobotics etc. Nanomaterials play important role in the modern development of science due to its small size and large surface area. Nanotechnology is expected to revolutionize certain areas, such as semiconductors, pharmaceuticals and materials. The total societal impact of nanotechnology is expected to be much greater than that of the silicon integrated circuits because it has applications in many more fields than electronics. The conference focussed on the topics like synthesis of nanomaterials, characterization of nanomaterials, applications of nanomaterials, fullerenes and carbon nanotubes, nanobiotechnology, nanophotonics, nano-devices and sensors, nano-bio, nanotoxicology and green technology, and theoretical/computational aspects. Papers relevant to INIS are indexed separately

[en] Nanosized single and binary metal oxides Sn_xZr_1-xO₂ with different compositions 0 ≤ x ≤ 1 were prepared at room temperature by sol-gel wet chemical route using ammonia as a hydrolyzing agent. As-prepared samples were annealed at 700℃ for 3h in air. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were employed to reveal the behavior of SnO₂-ZrO₂ nanocomposites. XRD spectra illustrate the mixture of different phases: tetragonal and monoclinic ZrO₂ (t-ZrO₂, m-ZrO₂), tetragonal SnO₂ (t-SnO₂) and orthorhombic ZrSnO₄ (o-ZrSnO₄). FTIR spectra exhibit the functional groups present in the samples. Various structural parameters were determined through above mentioned techniques. (author)

[en] Recently there is lot of interest in the structure and phase transition behavior of nanocrystalline manganites. The doped perovskites oxide manganites (with ABO3 structure) are fascinating because their electronic and crystal structure can be readily tuned by proper substitution of cations to get wide range of physical properties. The ground state of manganite solid solutions can have distinct crystallographic phases such as monoclinic with space group P21/m, orthorhombic with space groups Pnma, lmma, and tetragonal with space group 14/mmm, rhombohedral with space group R3 etc. depending upon the cationic radii, electronic configuration and ionic charge. Charge orbital ordered state observed in half doped manganites have equal amount of Mn+3 and Mn+4 ions at the B-site in the ABO3 perovskite structure. The half doped manganites give rise to the charge ordered state associated with a real space ordering of 1:1 Mn+3/Mn+4 species accompanying a structural change. We data. Our studies clearly show that for the nanocrystalline samples structure is monoclinic in P21/m space group whereas for bulk samples the structure is coexistence of orthorhombic phase in the Pnma space group and tetragonal phase in the 14/mmm space group. (author)

[en] Multiferroic material exhibits more than one ferroic properties (magnetic/ferroelectric/ferroelastic) in same phase. It has engrossed the scientists and researchers for their diverging applications such as magnetic field sensors, non-volatile and data storage multiple state memories etc. GdMnO₃ is one of the multiferroic compounds belonging to orthorhombic rare earth manganite family. For the optimization of the synthesizing conditions of nanostructured GdMnO₃, the modified sol-gel (nitrate route) technique was used. During the synthesizing process the precursor of GdMnO₃ was formed which was sintered at different temperature ranging from 300 to 800℃ for 2 hours. These samples were characterized with various techniques eg. X-ray diffraction (XRD), Raman, Fourier Transformation Infrared (FTIR) and UV-Visible spectroscopy. XRD patterns of GdMnO₃ at different sintering temperatures were analysed for phase determination. When precursor is sintered at 300℃ the XRD pattern shows the amorphous nature. As the sintering temperature is increased the crystallinity was found to improve. On sintering at 800℃, the pure crystalline GdMnO₃ phase appears having space group Pnma. The Raman and FTIR analysis show some interesting results which may be correlated to the XRD data. UV-Vis spectrum of the sample sintered at 300℃ shows an absorption peak at 2.39 eV whereas the completely crystallized sample sintered at 800℃ shows two absorption bands at 2.25 and 2.56 eV. These bands are attributed to the Mn (d-d) transition. Higher energy band (3.26, 4.40, 4.74 and 5.08 eV) are attributed to the charge transfer transition from O(2p) to Mn(3d) state. (author)

[en] The unique properties of nanocomposite materials have generated much interest in science community because these materials have a high surface to volume ratio leading to structural and optical properties different from those of bulk materials and exhibit unique functional applications. Rare earth oxides have been extensively investigated due to their fascinating properties such as enhanced luminescence efficiency; lower lasing threshold, high-performance luminescent devices, drug-carrying vehicle, contrast agent in magnetic resonance imaging (MRI), up-conversion materials, catalysts, and time-resolved fluorescence (TRF) labels for biological detection etc. In the present study nanocomposites of silica-gadolinium oxide have been successfully synthesized by sol-gel process using hydrochloric acid as a catalyst. Gd(NO₃)₃.6H₂O and TEOS were used as precursors and obtained powdered form of Gd₂O₃:SiO₂ composite. The powdered samples having 3.4 mol % Gd₂O₃ were annealed at 900℃ temperature for 6 h and characterized XRD, FTIR, SEM and TEM. The effect of annealing on the phase evolution of the composite system has been discussed in detail. It was found that the annealing of precursor plays a pivotal role to obtained crystalline phase of Gd₂O₃. Cubic phase of gadolinium oxide was completely developed for annealed sample at 900℃ (6h) with an average grain size ∼ 21 nm. (author)