Papers by Keyword: Indium Oxide

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Authors: Ju Hyun Myung, Hyoun Woo Kim, S.H. Shim
Abstract: We report on the first synthesis of nanosized In2O3 rods using the TEI as a precursor in the presence of oxygen. The samples were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy. XRD analysis revealed that the products are In2O3 phase with a tetragonal cubic structure. SEM analysis indicated that the obtained nanorods have a circular cross section and a diameter in the range of 50-150 nm.
146
Authors: Hyoun Woo Kim, Ju Hyun Myung, S.H. Shim, Woon Suk Hwang
Abstract: In2O3 materials consisting of dense arrays of vertically aligned rod-like structures were deposited on sapphire substrates by thermal chemical vapor deposition (CVD) using triethylindium (TEI) and oxygen as precursors at a substrate temperature of 350 oC. The rod-like structure with a triangular cross section had a cubic structure, exhibiting preferred crystallographic orientation in the [111] direction. The photoluminescence spectra of In2O3 structures under excitation at 325 nm revealed a visible emission.
143
Authors: E.C.C. Souza, E.N.S. Muccillo
Abstract: Indium oxide, a wide band gap transparent conductor, is of great interest for many device applications due to its unusual combination of high transparency in the visible region and high electrical conductivity. Several methods, comprising all three phases, namely, the solid phase, the solution phase, as well as the vapor phase, have been used for the preparation of In2O3 powders and thin films. In this work, indium oxide nanoparticles were synthesized by homogeneous precipitation using hexamethylenetetramine as ligand and indium nitrate or indium chloride as precursor materials. Thermogravimetry and differential thermal analysis results evidenced the relatively low temperature for crystallization of indium oxide. Spherical clusters consisting of about 8 nm of diameter indium oxide nanoparticles were obtained after thermal decomposition at 400 °C for 2 h, as revealed by X-ray diffraction experiments and nitrogen adsorption measurements. Transmission electron microscopy observations confirm the single-crystalline nature of the prepared nanoparticles. This material exhibits photoluminescence emission at room temperature with peak onset at 315 nm as a consequence of the small size of the particles.
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Authors: Jin Ho Yoon, Jung Sik Kim
Abstract: In this study, the micro gas sensor for NOx gas was fabricated by using a MEMS technology and sol-gel process. The sensing electrode and micro heater were designed to be a co-planar typed structure in the Pt thin film layer. The fabricated micro platform had a low power consumption of 67 mW at 2.0 V of heater voltage and 300°C of operating temperature. Indium oxide as a sensing material for NOx gas was synthesized by a sol-gel process with indium isopropoxide. The particle size of synthesized In2O3 was identified as about 50 nm. The maximum gas sensitivity as relative resistance (Rs = Rgas / Rair) occurred at 300°C with the value of 8.0 at 1 ppm NO2 gas. The present study shows that a MEMS-based gas sensor is a potential candidate for the automobile AQS (air quality system) gas sensor with many advantages of small dimension, high sensitivity, short response time and low power consumption.
255
Authors: V.S. Vaishnav, S.G. Patel, J.N. Panchal
Abstract: Volatile Organic Compounds (VOCs) are highly reactive, often mixed with interfering gases and more importantly, their vapours in the gaseous form respond to the gas sensor devices. Oxide semiconductor based thin film gas sensors play vital role in detecting, monitoring and controlling the presence of hazardous and harmful gases in the environment at very low concentration and hence are tested for the detection of harmful or industrially important VOCs. The demand of sensitive as well stable gas/vapour sensors for direct sensing application has increased the importance of In2O3:SnO2 based semiconductor materials. The paper presents the fabrication aspects of thin film gas sensors based on x1In2O3:x2SnO2 compound and also their application for the detection of some important volatile organic compounds. Thin films of x1In2O3:x2SnO2 were deposited using Thermal Evaporation technique and under the optimized fabrication conditions, the vapour sensors were prepared and mounted on the proper contact jig. Their response to the presence of Volatile Organic Compounds like CCl4 was examined. The stability, the sensitivity and the response time of the sensors were studied for the different concentrations of test vapours.
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Authors: Tomoyuki Endo, Yamato Hayashi, Jun Fukushima, Hirotsugu Takizawa
Abstract: Various (ZnO)5In2O3 ceramics were fabricated by microwave heating. Density, XRD pattern and microstructure were examined and those of Al-doped (ZnO)5In2O3 were almost the same as Al-free one. Highly textured (ZnO)5In2O3 ceramic was also fabricated by reactive templated grain growth (RTGG) method. The electrical conductivity was not improved by Al-doping; however it was improved slightly by microwave heating compared with conventional heating and especially improved by texturing using RTGG method. On the other hand, the absolute Seebeck coefficient in microwave heating was improved about 25% by Al-doped. Maximum electric power factor of textured specimen fabricated by RTGG method along ab-plane showed 5.76×10-4 WK-2m-1 (at 873K), which was attributed to high electrical conductivity.
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Authors: Hyoun Woo Kim, Jong Woo Lee, Jeong Whan Han, Hyung Sun Kim, Mok Soon Kim, Byung Don Yoo, Sun Keun Hwang
Abstract: Indium oxide (In2O3) films were successfully grown on LiAlO2 substrates using the triethylindium (TEI) as a precursor in the presence of oxygen in the metalorganic chemical vapor deposition process. We have established the correlation between the substrate temperature and the structural properties. The grain structures were clearly shown on the surface of the films deposited at 350°C. The root mean square (RMS) surface roughness of the In2O3 films increased with increasing the substrate temperature. A photoluminescence measurement at room temperature exhibited a yellow-green emission band centered at 585 nm.
625
Authors: Wei Huang, Jin Chun Tu, Yang Cao, Xiao Hong Wang, Jin Li, Kai Xiao
Abstract: In this paper, mesoporous indium oxide has been synthesized by the hard template route from the SBA-15 silica template. The results characterized from XRD, and N2 adsorption-desorption demonstrated that the synthesis can be controlled successfully in nanometer (meso-structure) scale. The obtained sample was investigated as humidity sensing material by coating on a ceramic plate, and the humidity sensing performance can be enhanced up to more than three orders of magnitude without any doping. Further testing proved that it is a promising humidity sensing material and can be widely used, and a possible mechanism was also provided.
1860
Authors: Alberto F. Pasquevich, Mario Rentería
Abstract: In this chapter Perturbed Angular Correlation (PAC) experiments on binary oxides are described. These experiments provide local-scale fingerprints about the formation, identification, and lattice environment of defect complexes at the PAC probe site. The potential of the PAC observations in conjunction with ab initio calculations is shown. Measurements of the electric-field gradient at impurity sites using 111Cd and 181Ta probes are reviewed. Special attention is paid to oxides with the bixbyite structure. The case of In2O3 is particularly analyzed. Results obtained with HfO2, in form of coarse grain or nano particles, are described. The potential results that can be obtained from Density Functional Theory ab initio calculations in doped systems are shown describing the main results observed in many impurity-host systems.
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Authors: Hyoun Woo Kim, Sun Keun Hwang, Won Seung Cho, Tae Gyung Ko, Seung Yong Choi, Wan In Lee, Sang Eon Park, Jung Hoon Joo, Dong Ik Kim, Seong Gyoon Kim, Byung Hak Choe, Seok Hong Min, Jae Ho Choi
Abstract: This paper reports the fabrication of indium oxide (In2O3) films using a triethylindium and oxygen mixture. The deposition has been carried out on TiAlN substrates (200-350°C). We have established the correlation between the substrate temperature and the structural properties. The films deposited at 300-350°C were polycrystalline, whereas those deposited at 200°C was close to amorphous. XRD analysis and SEM images indicated that the films grown at 350°C had grained structures with the (222) preferred orientation. The room-temperature photoluminescence spectra of the In2O3 films exhibited a visible light emission.
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