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Mechanochemically Synthesized CIGS Nanocrystalline Powder for Solar Cell Application  [PDF]
Journal of Nano- and Electronic Physics , 2013,
Abstract: Copper Indium Gallium Diselenide (CIGS) is a compound semiconductor material from the group of I-III-VI. The material is a solid solution of copper, indium and selenium (CIS) and copper, gallium and selenium with an empirical formula of CuIn(1 – x)GaxSe2, where 0 x 1. CIGS has an exceptionally high absorption coefficient of more than 105 cm – 1 for 1.5 eV. Solar cells prepared from absorber layers of CIGS materials have shown an efficiency higher than 20 %. CuIn(1 – x)GaxSe2 (x 0.3) nanocrystalline compound was mechanochemically synthesized by high-energy milling in a planetary ball mill. The phase identification and crystallite size of milled powders at different time intervals were carried out by X-ray diffraction (XRD). The XRD analysis indicates chalcopyrite structure and the crystallite size of about 10 nm of high-energy milled CIGS powder after two and half hours of milling. An attempt for preparing the thin film from CIGS nanocrystalline powder was carried out using the flash evaporation technique. Scanning electron microscopy (SEM) reveals uniform distribution of CIGS particles in thin film.
Structural and magnetic properties of mechanochemically synthesized nanosized yttrium titanate  [PDF]
Barud?ija Tanja,Gusev Alexey A.,Jugovi? Dragana,Marinovi?-Cincovi? Milena
Hemijska Industrija , 2012, DOI: 10.2298/hemind111103103b
Abstract: Nanosized perovskite YTiO3 with the mean crystallite size of 18 nm was synthesized for the first time by mechanochemical treatment. The mechanochemical solid state reaction between commercial Y2O3 powder and mechanochemically synthesized TiO powder in molar ratio 0.5:1 was completed for 3 h in a high-energy planetary ball mill in argon atmosphere. The heating in vacuum at 1150 °C for 12 h transforms nanosized YTiO3 to a well-crystallized single-phase perovskite YTiO3. Both samples were characterized by X-ray diffraction (XRD) and thermogravimetric (TGA/DTA) analyses, as well as superconducting quantum interference device magnetometer (SQUID) measurements.
Biomimetic helical rosette nanotubes and nanocrystalline hydroxyapatite coatings on titanium for improving orthopedic implants  [cached]
Lijie Zhang,Yupeng Chen,Jose Rodriguez,Hicham Fenniri
International Journal of Nanomedicine , 2008,
Abstract: Lijie Zhang1, Yupeng Chen2, Jose Rodriguez3, Hicham Fenniri3, Thomas J Webster11Division of Engineering, 2Department of Chemistry, Brown University, Providence, RI, USA; 3National Institute for Nanotechnology and Department of Chemistry, University of Alberta, Edmonton, AB, CanadaAbstract: Natural bone consists of hard nanostructured hydroxyapatite (HA) in a nanostructured protein-based soft hydrogel template (ie, mostly collagen). For this reason, nanostructured HA has been an intriguing coating material on traditionally used titanium for improving orthopedic applications. In addition, helical rosette nanotubes (HRNs), newly developed materials which form through the self-assembly process of DNA base pair building blocks in body solutions, are soft nanotubes with a helical architecture that mimics natural collagen. Thus, the objective of this in vitro study was for the first time to combine the promising attributes of HRNs and nanocrystalline HA on titanium and assess osteoblast (bone-forming cell) functions. Different sizes of nanocrystalline HA were synthesized in this study through a wet chemical precipitation process following either hydrothermal treatment or sintering. Transmission electron microscopy images showed that HRNs aligned with nanocrystalline HA, which indicates a high affinity between both components. Some of the nanocrystalline HA formed dense coatings with HRNs on titanium. More importantly, results demonstrated enhanced osteoblast adhesion on the HRN/nanocrystalline HA-coated titanium compared with conventional uncoated titanium. Among all the HRN/nanocrystalline HA coatings tested, osteoblast adhesion was the greatest when HA nanometer particle size was the smallest. In this manner, this study demonstrated for the first time that biomimetic HRN/nanocrystalline HA coatings on titanium were cytocompatible for osteoblasts and, thus, should be further studied for improving orthopedic implants.Keywords: helical rosette nanotubes, nanocrystalline hydroxyapatite, biomimetic, titanium, osteoblast, self assembled
Characterization of Nanocrystalline Intermetallic Compound NiAl Synthesized by Condensation
Yong QIN,Xiaoying QIN,Lide ZHANG,

材料科学技术学报 , 1996,
Abstract: Nanocrystalline intermetallic compound NiAl was Synthesized by evaporating NiAl master alloy in inert-gas followed by in situ compaction, and its structure was studied by means of X-ray diffractometry and transmission electron microscope. Experimental results reveal that the assynthesized nanocrystalline sample has a mean grain size of less than 10 nm and it is dominantly composed of the cubic structure phase NiAl. However, nanocrystalline Ni3Al as a trace phase mixed in NiAl phase, was also detected by transmission electron microscope observation.
Effects of Substrate Temperature on Helium Content and Microstructure of Nanocrystalline Titanium Films
PANG Hong-Chao&sup,LUO Shun-Zhong&sup,LONG Xing-Gui&sup,AN Zhu&sup,LIU Ning&sup,DUAN Yan-Min&sup,WU Xing-Chun&sup,YANG Ben-Fu&sup,WANG Pei-Lu&sup,ZHENG Si-Xiao,

中国物理快报 , 2006,
Abstract: Helium-charged nanocrystalline titanium films have been deposited by HeAr magnetron co-sputtering. The effects of substrate temperature on the helium content and microstructure of the nanocrystalline titanium films have been studied. The results indicate that helium atoms with a high concentration are evenly incorporated in the deposited titanium films. When the substrate temperature increases from 60℃ to 350℃ while the other deposition'parameters are fixed, the helium content decreases gradually from 38.6 at.% to 9.2at.%, which proves that nanocrystalline Ti films have a great helium storage capacity. The 20 angle of the Bragg peak of (002) crystal planes of the He-charged Ti film shifts to a lower angle and that of (100) crystal plane is unchanged as compared with that of the pure Ti film, which indicates that the lattice parameter c increases and a keeps at the primitive value. The grain refining and helium damage result in the diffraction peak broadening.
Low-Temperature Reverse Microemulsion Synthesis, Characterization, and Photocatalytic Performance of Nanocrystalline Titanium Dioxide
Zhang Liu,Zicong Jian,Jianzhang Fang,Xiaoxin Xu,Ximiao Zhu,Shuxing Wu
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/702503
Abstract: Nanocrystalline titanium dioxide (TiO2) was synthesized in microemulsions by using cetyltrimethylammonium bromide (CTAB) as surfactant. In order to investigate the crystal transformation and photoactivity at low temperature, the as-prepared precipitates were aged at 65°C or calcined at various temperatures. Analyses using powder X-ray diffraction (XRD) and Fourier transform infrared microscopy (FT-IR) showed that precursors without aging or calcination were noncrystal and adsorbed by surfactant. After aging for 6 h, the amorphous TiO2 began to change into anatase. The obtained catalysts, which were synthesized in microemulsions with weight ratios of n-hexanol/CTAB/water as 6 : 3 : 1 and calcined at 500°C, presented the highest photocatalytic degradation rate on methyl orange (MO), while the catalysts, which were aged at 65°C for 90 h, also exhibited an outstanding photocatalytic performance and a little higher than that of the commercial titania photocatalyst Degussa P25.
Nanocrystalline zirconia based powders synthesized by hydrothermal method
Viktoria Tsukrenko,Elena Dudnik,Alexey Shevchenko
Processing and Application of Ceramics , 2012,
Abstract: Nanocrystalline powders in the ZrO2-Y2O3-CeO2-CoO-Al2O3 system with 1 and 10 mol% Al2O3 were prepared via hydrothermal treatment in alkaline medium. The characteristics of nanocrystalline powders after heat treatment in the temperature range from 500 to 1200 °C were investigated by XRD phase analysis, scanning electron microscopy, petrography and BET measurements. It was found that hydrothermally treated powders contained metastable low-temperature cubic solid solution based on ZrO2 and addition of Al2O3 increased temperature of phase transformation of the metastable cubic- ZrO2 to tetragonal-ZrO2. It was evidenced that both powders remained nanocrystalline after all processing steps with the average particle sizes from 8 to 20 nm. The addition of 0.3 mol% CoO allows one to obtain composites with good sinterability at 1200 °C.
Photocatalytic Properties of Nanocrystalline TiO2 Synthesized by Highpressure Microwave Method
LIU Yu,ZHANG Ting,FU Min-Gong,LI Wang,DU Guo-Ping
无机材料学报 , 2010, DOI: 10.3724/sp.j.1077.2010.00375
Abstract: Nanocrystalline TiO2 powders were synthesized from TiCl4 solution by the highpressure microwave method under pressure ranging from 0.1MPa to 4.0MPa. The phase structures, microstructures and photocatalytic properties of the nanocrystalline TiO2 were investigated. It was found that the reaction pressure had a large impact on the phase structures, microstructures, and photocatalytic properties of the nanocrystalline TiO2. Under lower reaction pressure, TiO2 products consisted of anatase and brookite phase, with the brookite phase in minority, while under higher reaction pressure, a large quantity of rutile TiO2 was formed. With the increase of reaction pressure from 0.1MPa to 4.0MPa, the average sizes of the TiO2 nanoparticles increased from 5nm to 30nm. At reaction pressures lower than 2.0MPa, the photocatalytic performance of the nanocrystalline TiO2 increased with the pressure, while at pressures higher than 2.0MPa, the photocatalytic performance was found to decrease monotonically with the pressure.
Frequency Response of the Mechanochemically Synthesized AgI-Ag2O-B2O3 Superionic Glasses  [PDF]
Ankur Verma,K Shahi
Physics , 2007,
Abstract: The synthesis of xAgI(1-x)[Ag2O.B2O3] amorphous superionic conductors is done via mechanochemical synthesis route (for x = 0.5 and 0.7). Ionic conductivities of 3 mOhm-1cm-1 for x = 0.5 sample and 5mOhm-1cm-1 for x = 0.7 sample at room temperature, are observed, which are higher than those of the melt quenched glassy samples. Impedance plots (Nyquist plots) are found to be depressed semicircles with a tail at low frequency end. The corresponding equivalent circuit is postulated and each circuit element is related to a physical process. The ac conductivity is analyzed in view of the universal dynamic response (Bode Plots). A unique feature of the mechnochemically synthesized glasses is that their dc conductivity vs. 1/T behavior exhibit two distinct regions with different activation energies. The activation energy for dc conductivity (Edc) and that for ac conductivity (Eac) and the frequency exponent n are found to satisfy the UDR-relation, Eac= (1-n)Edc in the lower temperature regime. In the high temperature region, however, this correlation could not be established due to lack of sac data over the available frequency domain.
Adsorption of carbon monoxide on graphene with high titanium coverage
Carrillo, I.;Maga?a, L.F.;
Revista mexicana de física , 2009,
Abstract: density functional theory and molecular dynamics were used to study the adsorption of co on a graphene layer modifie with high titanium coverage (c2ti) at atmospheric pressure and 300 k. we found that the co molecule is adsorbed and dissociated.
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