In2O3 Doping Research Articles

Indium, as an efficient co‐catalyst of Cu/Al2O3 in the selective hydrogenation of biomass derived fatty acids to alcohols

Octanoic acid (OA) as model reactant of medium chain length, and its reduced products, octanal and octanol were hydroconverted over different components of a CuIn/Al2O3 composite catalyst. A fixed‐bed flow through reactor was used at 21 bar total pressure in the temperature range of 240–360 °C. Fatty acid hydroconversion activity of alumina supported Cu catalyst and mainly the yield of selectively produced octanol can be greatly increased by In2O3 doping, suppressing the dehydration side reactions. Appearance of metallic indium on alumina supported reduced copper catalyst can arrest the consecutive catalytic reaction at the alcohol formation step prior to further dehydration to ether or alkenes. An industrial, conventionally used Adkins catalyst (72 wt.% CuCr2O4 and 28 wt.% CuO) and the novel bimetallic composite (CuIn/Al2O3) were compared: both produce octanol with high selectivity, but the new chromium‐free fatty acid hydrogenation catalyst is more active, nearly as active as earlier investigated NiIn/Al2O3.

Major effect on electrical properties and aging behavior of ZnO–Pr6O11-based varistor ceramics with small In2O3 doping changes

The effect of In2O3 doping on microstructure, electrical properties, and DC-accelerated aging behavior of the ZnO–Pr6O11-based varistor ceramics was systematically investigated. The addition of In2O3 did not significantly alter the sintered density increasing in the small range of 5.60–5.63 g/cm3 and the average grain size decreasing in the small range of 3.4–2.9 μm. However, the incorporation of In2O3 pronouncedly increased the breakdown field from 6,023 to 14,822 V/cm. Furthermore, the incorporation of In2O3 markedly improved the nonlinear coefficient (45 at 0.005 mol% In2O3) and it saliently suppressed the leakage current density (7.3 µA/cm2 at 0.005 mol% In2O3). In2O3 acted like the role of acceptor due to the donor concentration, which decreases in the range of 1.02 × 1017–0.24 × 1017 cm−3 with an increase in the content of In2O3. The ceramics added with 0.005 mol% In2O3 exhibited an excellent stability, with %ΔE1mA = 0% and %Δα = −2.2% under DC-accelerated aging stress state of 0.85 E1mA/115°C/24 h.

The effect of In3+ ion on the optical characteristics of Er3+ in Er/Yb:LiNbO3 crystal

The effect of In3+ ion on the optical characteristics of Er3+ ion in Er/Yb:LiNbO3 crystal under 980nm excitation has been investigated. The Er and Yb contents in the crystals were measured by an inductively coupled plasma atomic emission spectrometer (ICP-AES). A significant enhancement of 1.54μm emission was observed for Er/Yb:LiNbO3 crystal doped with 1mol% In2O3. The studies on the UV–vis absorption and the OH− absorption spectra indicate that the threshold concentration of In3+ ion decreases with the Er/Yb doping in Er/Yb/In:LiNbO3 crystal. The 1mol% In2O3 doping results in the reduction of absorption cross section in the UV–vis region, meaning the formation of Er3+ cluster sites. The enhancement of 1.54μm emission is attributed to the larger probabilities of the cross relaxation processes 4S3/2+4I15/2→4I9/2+4I13/2 (Er), 4S3/2+4I15/2→4I13/2+4I9/2 (Er) and 4I9/2+4I15/2→4I13/2+4I13/2 (Er) induced by Er3+ cluster sites.

Improving the catalytic behavior of Ni/Al2O3 by indium in reduction of carboxylic acid to alcohol

Octanoic acid (OA) was used as reactant with medium chain length to model the aliphatic carboxylic acids which can be produced by catalytic, thermochemical or biological degradation of biomass. A flow through reactor was applied at 21 bar total pressure (in general 20 bar hydrogen and 1 bar octanoic acid partial pressures) and 240–360 °C. Fatty acid conversion activity of alumina supported Ni catalysts and the yield of selectively produced alcohol can be increased drastically by In2O3 doping. Appearance of metallic indium can effectively direct the step by step catalytic reduction to alcohol formation over partly reduced Ni catalysts instead of chain shortening hydrodecarbonylation. On comparing a commercial, conventionally used Adkins catalyst (consisting of 72 wt.% CuCr2O4 and 28 wt.% CuO) and novel bimetallic alumina supported composite (InNi/Al2O3) producing alcohol with high selectivity, the chromium-free, environmental benign hydrogenation catalyst seems to be much more active.

Emission and absorption cross section spectra of Er3+ in LiNbO3 crystals codoped with indium

Abstract

The Effect of GeO2 and In2O3 Doping on the Dielectric Properties of CaCu3Ti4O12 Ceramics Prepared via Vibro-Milling Method

In this work, effects of GeO2 and In2O3 doping on the dielectric properties of CCTO were investigated. Doping levels range from 0.5 to 2.0 mol%. The vibro-milling method was employed for processing. The dopant addition produced a slightly smaller grain size. A reduction in dielectric constant was observed, but it is still high. The 2.0 mol% GeO2 and In2O3 doped samples exhibited high dielectric constant of about 25,000 and 23,000 and low dielectric loss with 0.06 and 0.05 respectively at room temperature and at 10 kHz. The dielectric measurements showed that the modified samples exhibited a strong dielectric independency of temperature and frequency. In addition, the loss tangent reduced after doping. From this results, it can be incurred that GeO2 and In2O3 doping, processed via vibro-mill are the suitable methods to achieve the stability of high ϵr and low loss ceramics.

Judd-Ofelt Spectroscopic Study of Er:In:LiNbO3 Crystals For Integrated Optics

Er:In:LiNbO3 crystals were grown by Czochralski method from congruent melts containing 0.5/0.5, 0.5/1.0, and 0.5/1.5 mol%/mol% Er2O3/In2O3. The Er and In concentrations in the crystals were determined by neutron activation analysis. The refractive indices at the 473, 633, and 1536 nm wavelengths were measured by prism coupling technique. The unpolarized Er3+ and OH− absorption spectra of the crystals were measured at room temperature. The Er3+ absorption cross-section spectra were determined, and the Er3+ spectroscopic properties were analyzed by Judd–Ofelt (J–O) theory. The In segregation coefficient is 1.20 ± 0.06, 0.95 ± 0.05, and 0.89 ± 0.05, respectively, and the Er concentrations in all of the three crystals studied have a nearly same value of 1 mol%. The ordinary index decreases while the extraordinary index increases with the increased In doping level. The 0.5 and 1.0 mol% In2O3-doped two crystals are below while the 1.5 mol% In2O3-doped crystal is above the photorefractive threshold concentration. The Er3+ absorption cross sections of some transitions change definitely due to In codoping, but reveal a weak dependence on the In2O3 doping level. The J–O-predicted spectroscopic parameters show similar In codoping effects. The In codoping hardly affects the Er3+ 1.5 μm radiative lifetime.

PERHITUNGAN POLARISASI SPONTAN DAN MOMEN QUADRUPOL POTENSIAL LISTRIK BAHAN PIZT (PbInxZryTi1-x-yO3-x/2)

The Calculation Spontaneous Polarization and Quadrupole Moment of Electric Potential PIZT (PbInxZryTi1-x-yO3-x/2). PZT (PbZr1-xTixO3) is a perovskite crystal that can be used for IR sensor. Small amount of dopant can drastically change the specific characteristic of ferroelectric ceramic such as spontaneous polarization, dielectric constant, electromechanical and also electro-optic properties. The addition of In3+ ion (called as hard doping) has been applied in this research. Thin film of PIZT (PbInxZryTi1-x-yO3-x/2) has been deposited on Si(100) substrate with Chemical Solution Deposition (CSD) method. The concentration of solution is 0,5 M and the angular speed applied of spin coating is 3000 rpm. The PIZT sample has been analyzed with x-ray diffraction method. Rietveld analyses using GSAS-EXPGUI software resulted lattice parameter of crystal and phase compositions of PIZT samples. The values of all sample PIZT spontaneous polarization (Ps) have been calculated lower than PZT. The optimally Ps was reached at 0,5% to 1% In2O3 doping. Quadrupole moment of electric potential Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 ( θ Q ( r )) at point P (0,0,2 a ) reached optimum at 6% In2O3 doping and they also showed that PIZT thin film have θ Q ( r ) higher value than their bulk form for In2O3 doping >1%. Keywords: PZT, PIZT, XRD, Rietveld analyses, spontaneous polarization, quadrupole moment of electric potential

Control of Ferromagnetism via Electron Doping inIn2O3∶Cr

Carrier-induced ferromagnetism in wide-gap transparent conductive oxides has been widely discussed and debated, leading to confusion and skepticism regarding whether dilute magnetic oxides exist at all. We show from density-functional calculations within a band-gap corrected approach that ferromagnetic Cr-Cr coupling can be switched on and off via electron doping in the wide-gap transparent n-type conductive oxide In2O3. We show that (i) Cr does not produce in In2O3 any free electrons and renders the system an insulating paramagnet. (ii) Extrinsic n-type doping of In2O3:Cr via Sn produces free electrons, whose concentration is controllable via the oxygen partial pressure. Such additional carriers stabilize a strong long-range Cr-Cr ferromagnetic coupling.

Ozone and gamma radiation sensing properties of In2O3:ZnO:SnO2 thin films

Both gamma radiation and ozone sensing properties of mixed oxides in the form of thin films are explored. External effects, such as radiation and ozone, cause defects in the materials it interacts with and, consequently, it causes changes in their properties. These changes manifest themselves as the alterations in both the electrical and the optical parameters, which are being measured and employed for dosimetry sensor development. An Edwards E306A thermal coating system was used for In2O3:ZnO:SnO2 (90%:5%:5%) films deposition. For the electrical properties measurements, Cu electrodes were manufactured on the glass substrate via thermal evaporation of Cu; then AZ5214 photoresist was spin-coated over it and exposed to ultraviolet (UV) light via the acetate, containing the desired electrodes patterns. After the exposure, the substrate was placed in Electrolube PDN250ML developer solution and then rinsed in water and placed in the etching solution of SEMO 3207 fine etch crystals to reveal the electrode pattern. The optical properties of In2O3:ZnO:SnO2 thin films were explored using CARY 1E UV–visible spectrophotometer. The values of the optical band gap Eopt are estimated in the view of the Mott and Davis’ theory. Doping of In2O3 with 5% ZnO and 5% SnO2 dramatically changes the overall structure of the film and thus affects its sensing to gamma radiation and ozone. Mixing metal oxides in certain proportions provides a tool for controlling the sensors response.

Lead-free In2O3-doped (Bi0.5Na0.5)0.93Ba0.07TiO3 ceramics synthesized by direct reaction sintering

Lead-free (Bi0.5Na0.5)0.93Ba0.07TiO3–xwt%In2O3 ceramics synthesized by direct reaction sintering have been studied. X-ray diffraction reveals that all (Bi0.5Na0.5)0.93Ba0.07TiO3–xwt%In2O3 ceramics are of a perovskite structure with coexistence of rhombohedral and tetragonal phases. It is found that the direct reaction sintering promotes growing of ceramic grains while doping of In2O3 contributes to inhibit and homogenize the grain growth, as shown by scanning electron microscopy. The ceramics show excellent piezoelectric and dielectric properties with thickness electromechanical coupling factor kt=0.503, piezoelectric constant d33=205pC∕N, dielectric constant ε33T∕ε0=1046, and loss tangent tanδ=0.036.

Hydrogen-discriminating nanocrystalline doped-tin-oxide room-temperature microsensor

Highly hydrogen (H2)-selective [relative to carbon monoxide (CO)] sensor, operating at room temperature, has been fabricated using the micronanointegration approach involving the deposition of the nanocrystalline indium oxide (In2O3)-doped tin oxide (SnO2) thin film on microelectromechanical systems device. The present microsensor exhibits high room-temperature sensitivity towards H2 (S=12700); however, it is insensitive to CO at room temperature. In view of the different gas selectivity mechanisms proposed in the literature, it is deduced that the In2O3 doping, the presence of InSn4 phase, the low operating temperature (room temperature), the mesostructure, the small sizes of H2 and H2O molecules, the bulky intermediate and final reaction products for CO, and the electrode placement at the bottom are the critical parameters, which significantly contribute to the high room-temperature H2 selectivity of the present microsensor over CO. The constitutive equation for the gas sensitivity of the semiconductor oxide thin-film sensor, proposed recently by the authors, has been modified to qualitatively explain the observed H2 selectivity behavior.

Enhanced luminance of ZnGa2O4 phosphor by In2O3 doping

This article describes the effect of In2O3 doping on the luminance of ZnGa2O4 phosphor. The crystalline properties, photoluminescence (PL), cathodoluminescence (CL), and resistivity of the In2O3-doped ZnGa2O4 phosphor will be discussed. The PL wavelength of In2O3-doped ZnGa2O4 phosphor is centered at 4020 Å; it is insensitive to the In2O3 doping. However, the PL intensity depends on the In2O3 concentration, and it initially increased, then decreased with the concentration of In2O3. The CL intensity of phosphor also depends on the concentration of the In2O3 dopant. The maximum CL intensity of the In2O3-doped ZnGa2O4 phosphor is obtained at an In2O3 concentration of 12 wt %. At this doping level, a minimum resistivity of 1.4 MΩ m of phosphor is obtained. In conclusion, the luminance of ZnGa2O4 phosphor is enhanced by In2O3 doping.

Effects of In2O3 doping and sintering temperature on the electrical properties of ZnO varistors

ZnO varistors are prepared using the 0.1–0.3 mm ZnO powders. The effects of the sintering temperature, contents of In2O3 doping on the non-linear properties of ZnO varistors have been investigated. The results show that this kind of ZnO powder has a high sintering activity. It is suitable for making the low voltage varistors. The V c decreases with the increase of sintered temperature, when the In2O3 content is fixed (0.98%, mass fraction), and increases with the increase of In2O3 contents when the temperature is steady.

Estimation and verification of the electrical properties of indium tin oxide based on the energy band diagram

Indium tin oxide (ITO) is a transparent conducting oxide used in a variety of optoelectronic applications. In order to optimize the electrical conductivity of ITO thin films it is necessary to determine this property as a function of optimum electron concentration (e.g., doping of In2O3 with Sn). A new software program called CRYSTAL 92 is used to determine the energy band diagrams of In2O3 and In2O3 doped with Sn. Using the curvature of the conduction bands, the effective mass of the electrons is estimated and an empirical relationship is established between the effective mass and free carrier concentration using experimentally observed optical effective mass values. The importance of the varying electron effective mass in the prediction of the electron mobility, and hence the electrical conductivity, is shown here by comparing the published experimental results with the estimated results. The limiting factor in the electron mobility appears to be either grain boundary scattering or ion impurity scattering. The mobility due to neutral impurity scattering appears to have a negligible effect on the overall mobility unless the neutral impurity concentration reaches extremely high values.

Effects of dopants on the deep bulk levels in the ZnO-Bi2O3-MnO2 system

Small amounts of In2O3 and Li2O were added to the ZnO-Bi2O3-MnO2 ternary primitive varistor system. Considering Schottky disorder and Frenkel disorder, oxygen vacancy or zinc interstitial density was expected to decrease with In2O3 doping and to increase with Li2O doping. Using admittance spectroscopy, a 0.32-eV electron trap, which is suggested to be an ionized oxygen vacancy, was observed regardless of the doping conditions. Changes in the peak height, for the 0.32-eV trap, in the admittance spectra are correlated with In2O3 and Li2O doping. Doping with In2O3 reduces the conductance contribution due to the trap, while doping with Li2O enhances it. However, calculations show that small amounts of dopants, less than 100 ppm, do not greatly influence the trap density. The trap density remains within experimental error approximately 1.0×1017 cm−3.