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Growth, Optical, Mechanical, Dielectric and Theoretical Studies on Potassium Pentaborate Tetrahydrate (KB5O8?4H2O) Single Crystal by Modified Sankaranarayanan-Ramasamy Method
C. Justin Raj,S. Krishnan,S. Dinakaran,J. Mary Linet,R. Uthrakumar,R. Robert,S. Jerome Das
J Mater Sci Technol    2009, 25 (06): 745-748.  
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A nonlinear optical single crystal of potassium pentaborate tetrahydrate (KB5O8? 4H2O) has been grown from aqueous solution by using unidirectional crystal growth method of Sankaranarayanan-Ramasamy (SR) with a due modification in the growth assembly. Potassium pentaborate crystal of 60 mm length and 10 mm diameter has been grown along (100) plane with a growth rate of 3 mm per day within a period of 20 days. The grown crystal was subjected to single crystal X-ray diffraction analysis to confirm that the crystal belongs to the orthorhombic system. Some fundamental data such as valance electron plasma energy, Penn gap, Fermi energy and electronic polarizability of the grown crystal were calculated. The presence of borate in the grown crystal was confirmed by Fourier transform infrared (FTIR) spectroscopy. The optical transmission property of the grown crystal was analyzed using ultra violet (UV) visible spectral analysis. Surface morphology of the growth plane was observed using scanning electron microscopy (SEM). The mechanical strength of the crystals was found out using Vickers microhardness test along the growth axis. Frequency dependent dielectric constant of the grown crystal was studied for various temperatures along (100) plane.

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Factors Affecting the Growth of SiC Nano-whiskers
Y.F. Chen, X.Z. Liu, X.W. Deng
J Mater Sci Technol    2010, 26 (11): 1041-1046.  
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Silicon carbide (SiC) is a IV-IV compound semiconductor material with a wide band gap. Semiconductor electronic devices and circuits made from SiC are presently developed for high-temperature, high-power, and high-radiation conditions, in which conventional semiconductors cannot be adequately performed. In this paper, SiH4 and C2H2 were used to synthesize SiC nano-whiskers. Metal Ni was the catalyst. SiC nano-whiskers were grown by vapor-liquid-solid mechanism. The effects of the H2 flow rate, growth temperature, catalyst thickness and growth pressure to grow SiC nano-whiskers were studied. 3C-SiC thin film and nano-tips can be synthesized by controlling the growth conditions.
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Analysis of the Interaction of Pulsed Laser with Nanoporous Activated Carbon Cloth
B.V. Kaludjerovic, M.S. Trtica, B.B. Radak, J.M. Stasic, S.S. Krstic Musovic, V.M. Dodevski
J Mater Sci Technol    2011, 27 (11): 979-984.  
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Interaction of pulsed transversely excited atmospheric (TEA) CO2-laser radiation at 10.6 μm with nanoporous activated carbon cloth was investigated. Activated carbon cloth of different adsorption characteristics was used. Activated carbon cloth modifications were initiated by laser pulse intensities from 0.5 to 28 MW/cm2, depending on the cloth adsorption characteristics. CO2 laser radiation was effectively absorbed by the used activated carbon cloth and largely converted into thermal energy. The type of modification depended on laser power density, number of pulses, but mostly on material characteristics such as specific surface area. The higher the surface area of activated carbon cloth, the higher the damage threshold.
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High Hole Mobility of GaSb Relaxed Epilayer Grown on GaAs Substrate by MOCVD through Interfacial Misfit Dislocations Array
Wei Zhou, Xiang Li, Sujing Xia, Jie Yang, Wu Tang, K.M. Lau
J Mater Sci Technol    2012, 28 (2): 132-136.  
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The structural property of GaSb epilayers grown on semi-insulator GaAs (001) substrate by metalorganic chemical vapor deposition (MOCVD) using Triethylgallium (TEGa) and trimethylantimony (TMSb), was investigated by variation of the Sb:Ga (V/III) ratio. An optimum V/III ratio of 1.4 was determined in our growth conditions. Using transmission electron microscopy (TEM), we found that there was an interfacial misfit dislocations (IMF) growth mode in our experiment, in which the large misfit strain between epilayer and substrate is relaxed by periodic 90 deg. IMF array at the hetero-epitaxial interface. The rms roughness of a 300 nm-thick GaSb layer is only 2.7 nm in a 10 μm×10 μm scan from atomic force microscopy (AFM) result. The best hole density and mobility of 300 nm GaSb epilayer are 5.27×106 cm-3(1.20×106) and 553 cm2?V−1?s−1 (2340) at RT (77 K) from Hall measurement, respectively. These results indicate that the IMF growth mode can be used in MOCVD epitaxial technology similar to molecular beam epitaxy (MBE) technology to produce
the thinner GaSb layer with low density of dislocations and other defects on GaAs substrate for the application of devices.
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ZnCl2-assisted Synthesis of ZnSe Polycrystal
Changyou Liu, Tao Wang, Gangqiang Zha, Zhi Gu, Wanqi Jie
J Mater Sci Technol    2012, 28 (4): 373-378.  
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A chemical-assisted element direct-reaction method is developed to synthesize ZnSe compound semiconductor material at a relatively low temperature (~1000 °C). ZnSe polycrystal was obtained in the closed-tube systems with Zn-Se, Zn-Se-Zn(NH3)2Cl2, Zn-Se-NH4Cl and Zn-Se-ZnCl2. The as-synthesized samples were tested by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and analyzed by thermodynamic numerical
method. The results demonstrate that the synthesis efficiency is higher than 99.96% for Zn-Se-ZnCl2 system at around 1000 °C for 3 weeks. It also exhibits that not only temperature, but also low apparent ratio of volume and surface area of the source materials and higher ZnCl2 content are required to achieve high synthesis efficiency. A SeCl transporting reaction synthesis process is proposed based on the thermodynamic analysis.
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Effect of Thickness of SnO2:F over Layer on Certain Physical Properties of ZnO:Al Thin Films for Opto-electronic Applications
P. Ravikumar, K. Ravichandran, B. Sakthivel
J. Mater. Sci. Technol.    2012, 28 (11): 999-1003.  
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Bilayered FTO/AZO (fluorine doped tin oxide/aluminium doped zinc oxide) films were fabricated using a simple, cost effective spray pyrolysis technique. X-ray diffraction (XRD) profiles of bilayered films showed that in the case of lower thickness FTO over layers, (002) plane of ZnO phase had the highest intensity, whereas the predominance was changed in favour of (200) plane of SnO2 phase for higher thickness FTO over layer. UV studies showed that bilayered FTO/AZO films exhibited a sharp absorption edge as that of AZO film. The decrease in the photoluminescence (PL) peak at 420 nm with increasing FTO over layer thickness indicated a reduction in the zinc vacancies which caused a reduction in the sheet resistance (Rsh). Electrical studies revealed that, eventhough the Rsh value (916 Ω­/?) of bilayered FTO (313 nm)/AZO (314 nm) film was found to be higher than that of FTO single layer film (72 ­Ω­/?), it was much lower than that of AZO single layer film (5661 Ω­/?). The atomic force microscopy (AFM) images reflect the characteristic features of both
zinc oxide and tin oxide films.

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Preparation and Characterization of Flower-like Cu2SnS3 Nanostructures by Solvothermal Route
Xiaojuan Liang, Qian Cai, Weidong Xiang, Zhaopin Chen, Jiasong Zhong, Yun Wang, Mingguo Shao, Zhenrong Li
J. Mater. Sci. Technol.    2013, 29 (3): 231-236.   DOI: 10.1016/j.jmst.2012.12.011
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Flower-like Cu2SnS3 nanostructures composed of nano-flakes were successfully synthesized by solvothermal technique at 180 oC for 16 h. In the preparation process, CuCl2·2H2O, SnCl2·2H2O and thiourea were used as raw materials, and ethylene glycol were used as solvent. The results showed that the obtained product was pure phase Cu2SnS3. The average diameter of Cu2SnS3 flowers and the thickness of the nano-flakes were about 1e1.5 mm and 10 nm, respectively. The influence of reaction time and solvents on the morphology, size and structure of the products was investigated by powder X-ray diffraction and field-emission scan electron microscopy (FESEM). The ultraviolet-visible absorption spectrum measurement indicated that the band gap of the sample was about 1.26 eV and could be applied to the absorbing layer of thin solar cell. The possible formation mechanism of flower-like Cu2SnS3 was also proposed and discussed.

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Effect of Sodium Metasilicate on Structural, Optical, Dielectric and Mechanical Properties of ADP Crystal
Mohd Anis, M.D. Shirsat, S.S. Hussaini, B. Joshi, G.G. Muley
J. Mater. Sci. Technol.    2016, 32 (1): 62-67.   DOI: 10.1016/j.jmst.2015.09.010
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For the first time, sodium metasilicate (SMS) doped ammonium dihydrogen phosphate (ADP) crystal was grown by slow evaporation solution technique. The unit cell parameters of grown crystal were determined by means of single crystal X-ray diffraction technique. The qualitative analysis of SMS doped ADP crystal was carried out using energy dispersive X-ray and Fourier transform infrared analysis. The increase in optical transparency of doped ADP crystal was ascertained in the range of 200-900 nm using the UV-visible spectral analysis. The vital optical constants were evaluated using the transmittance data to explore various optical device applications of crystal. The assertive influence of SMS on mechanical and dielectric behavior of ADP crystal was investigated by means of Vickers microhardness analysis and dielectric studies, respectively. The enhancement in second harmonic generation (SHG) efficiency of SMS doped ADP crystal with reference to potassium dihydrogen phosphate (KDP) and ADP was confirmed from Kurtz-Perry SHG test. The Kerr lensing nonlinearity in SMS doped ADP crystal was identified by means of Z-scan analysis and the third order nonlinear optical susceptibility (χ3) was found to be 6.19 × 10-5 esu, which vitalizes its application for laser stabilization systems.
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