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Chunfei Li, Virgil Solomon, Marjan Moro, Chad Welsh, Tyler McCauley, Michael Bauer and Joseph Cupo

Abstract

In an effort to synthesize doped ZnO nanowires, SiOx nanowires were obtained accidently. In the experiment, mixed powders containing chemicals such as ZnO, graphite, Ga2O3, and In2O3 were placed in the center of a tube furnace, where the temperature was set to 1200 °C and the vacuum was approximately 27 Pa. Silicon wafers were placed around the vicinity of the furnace exit to collect the expected nanomaterials. After prolonged heating, grey layers were found on top of one wafer located inside the furnace. The layer showed no adhesion to the substrate. Characterization by using Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and Energy Dispersive X-ray Spectroscopy (EDS) revealed that this layer consisted of SiOx nanowires. Formation of Si-containing liquid drop and the subsequent growth of SiOx nanowires out of it are suggested as the growth mechanism.

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K. Ravindranadh and M.C. Rao

Abstract

During recent decades, magnetic and semiconductor nanoparticles have attracted significant attention of scientists in various fields of engineering, physics, chemistry, biology and medicine. Fe3+ doped PVA capped CdTe nanoparticles were prepared by co-precipitation method and characterized by powder X-ray diffraction, SEM, TEM, FT-IR, optical, EPR and PL techniques to collect the information about the crystal structure, coordination/local site symmetry of doped Fe3+ ions in the host lattice and the luminescent properties of prepared sample. Powder XRD data revealed that the crystal structure belongs to a cubic system and its lattice cell parameters were evaluated. The average crystallite size was estimated to be 8 nm. The morphology of prepared samples was analyzed by using SEM and TEM investigations. Functional groups of the prepared sample were observed in FT-IR spectra. Optical absorption and EPR studies have shown that on doping, Fe3+ ions enter the host lattice in octahedral site symmetry. PL studies of Fe3+ doped PVA capped CdTe nanoparticles revealed UV and blue emission bands. CIE chromaticity coordinates were also calculated from the emission spectrum of Fe3+ doped PVA capped CdTe nanoparticles.

Open access

T. Hongo, H. Wakasa and A. Yamazaki

. Health. Part. A, 28 (1993), 1875. [17] Hermosin M.C., Pavlobic I., Ulibarri M.A., Cornejo J., Fresenius Environ. Bull., 4 (1995), 41. [18] Hermosin M.C., Pavlovic I., Ulibarri M.A., Cornejo J., Water Res., 30 (1996), 171. http://dx.doi.org/10.1016/0043-1354(95)00088-3 [19] Ulibarri M.A., Pavlovic I., Hermosin M.C., Cornejo J., Appl. Clay Sci., 10 (1995), 131. http://dx.doi.org/10.1016/0169-1317(95)00020-5 [20] Kovanda F., Kovacsova E., Kolousek D., Collect. Czech

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Xiang Wei Kong, Rong Liang Zhang, Sheng Kui Zhong and Ling Wu

was used to provide a 12 kV voltage for the as-prepared electrospinning solution. A piece of flat aluminum foil was used to collect the nanofibers. The distance between the tip of the dropper and the collector was 15 cm. In the electric field, a polymer jet was ejected and accelerated toward the counter electrode. The solvent evaporated rapidly as the high-surface-area steam traveled to the target. Dry fibers accumulated randomly on the collection screen and were collected as a fibrous mat. The PVP-NiO composite nanofibers were then heated at a rate of 2 °C·min −1

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Janusz Typek, Nikos Guskos, Grzegorz Zolnierkiewicz, Aleksander Guskos, Kielbasa Karolina, Rafal Pelka and Walerian Arabczyk

all investigated samples is presented in Fig. 5 . Each rectangle in that figure collects components arising from the same phase. The difference of the resonance fields of both components (one in high H h (perpendicular orientation) and the other in low field H L (parallel orientation)) arising from the same phase could be correlated with the effective uniaxial anisotropy field H a of that phase by using the relation [ 33 ]: (3) H a   =   2 3 ( H h − H L ) $${H_a}\, = \,{2 \over 3}({H_h} - {H_L})$$ Fig. 5

Open access

Franciszek Balik and Andrzej Dziedzic

resistors must demonstrate smaller than 5 % scattering of resistance). Therefore, we paid special attention to the model accuracy and its temperature dependence. The mathematical models in the form of a multiplication of two 1D-and 2D-polynomials were elaborated for 5 types of thick-film resistors. The paper is organized as follows: in Section 2 , the measurement and data collecting system is described, while in Section 3 the modeling method is explained; Section 4 contains description of the modeling results. 2 Experimental 2.1 Measurement system At

Open access

Krzysztof Zdunek, Lukasz Skowroński, Rafal Chodun, Katarzyna Nowakowska-Langier, Andrzej Grabowski, Wojciech Wachowiak, Sebastian Okrasa, Agnieszka Wachowiak, Olaf Strauss, Andrzej Wronkowski and Piotr Domanowski

values at which the glow discharge was initiated and vanished periodically. As it was mentioned before the crucial goal of the experiments was to check the uniformity of the optically sensitive coatings deposited under the GIMS conditions ex-ploited in an industrial scale facility. According to the results reported in the literature [23] we were sure that the presently produced layers in the ar-gon/oxide mixture atmosphere were made from TiO₂. Table 1 collects the thickness and resistance measurement results of the obtained layers. Fig. 3 Reflectance spectra

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Łukasz Kosior, Damian Radziewicz, Iwona Zborowska-Lindert, Andrzej Stafiniak, Mikołaj Badura and Beata Ściana

or wet chemical etching it was needed to collect data from each experimental step. 3.1 Mask film After etching the structure in 1HCl:3H 3 PO 4 to a depth of about 2 µm there were no significant differences between the materials used as the masks ( Fig. 4a ). This situation changed when the depth reached 10 µm ( Fig. 4b ). The photoresist mask was underetched, forming rounded tops of the islands. Differences could be seen also in the slopes in 1 1 ¯ 0 $\left\langle {1\;\bar 1\;0} \right\rangle$ direction, which were not oriented according to the

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M. Bhuvaneswari, S. Sendhilnathan, M. Kumar, R. Tamilarasan and N.V. Giridharan

nanopowders doped with cobalt. 3.1.1 W-H analysis Since the breadth of the Bragg peak is the combination of both instrumental and sample dependent effects, it is necessary to collect a diffraction pattern from the line broadening of a standard material such as silicon to determine the instrumental broadening [ 15 ]. The instrumental corrected broadening β hkl corresponding to the diffraction peak of Co x Mn y Zn y Fe 2 O 4 was estimated from the relation: β h k l = [ ( β h k l ) m e a s u r e d 2 − β i n s t r u m e n t a l 2 ] 1 / 2 $${\beta

Open access

M. Jamshidiyan, A.S. Shirani and Gh. Alahyarizadeh

water and ethanol, and dried at 70 °C in vacuum environment for 4 h. 2.3 Characterization Four available systems, XRF, XRD, SEM and FT-IR were used to characterize and compare the synthesized magnetite Fe 3 O 4 nanoparticles. XRD, Bruker D8 Advance diffractometer was used to collect XRD patterns at 30 kV and 20 mA, and CuKα radiation (λ = 0.1540598 nm). The particle sizes of synthesized nanoparticles were measured by FE-SEM (HITACHI S-4160). The crystallite size of the synthesized magnetic Fe 3 O 4 nanoparticles was estimated based on the Scherrer equation