Indium tin oxide (ITO) thin films were prepared on glass substrates by an electron beam evaporation technique from a mixture of In 2 O 3 and SnO 2 . The films were annealed in air for 30 min at 350°C. The electrical and optical properties of these films were investigated as a function of the substrate temperature. The films were deposited at substrate temperatures ranging from 50 to 350°C at an oxygen partial pressure of 5×10 −5 mbar. The dopant concentration, resistivity, electrical conductivity, activation energy, optical transmission and band gap energy were investigated. It was found that the activation energy decreased with an increase in the film thickness. A transmittance value of 92% in the visible region of the spectrum and a resistivity of 3×10 −6 Ωm was obtained at a substrate temperature of 350°C. Structural studies showed that the films were polycrystalline.

Electrical and optical properties of electron beam evaporated ITO thin films

Comparative study of ITO and FTO thin films grown by spray pyrolysis

The effect of annealing on structural, electrical and optical properties of nanostructured ITO films prepared by e-beam evaporation

Water oxidation is a required half-reaction for electrochemical water splitting. To date, the only well-established active oxygen-evolution catalysts stable under operating conditions and at rest in acidic aqueous media contain Ru or Ir, two of the scarcest non-radioactive elements on Earth. We report herein a nickel-manganese antimonate electrocatalyst with a rutile-type crystal structure that requires an initial voltammetric overpotential of 672 ± 9 mV to catalyze the oxidation of water to O2(g) at a rate corresponding to 10 mA cm−2 of current density when operated in contact with 1.0 M sulfuric acid. Under galvanostatic control, the overpotential initially rose from 670 mV but was then stable at 735 ± 10 mV for 168 h of continuous operation at 10 mA cm−2. We additionally provide an in-depth evaluation of the stability of the nickel-manganese antimonate electrocatalyst, including elemental characterization of the surface, bulk, and electrolyte before and after electrochemical operation.

Crystalline nickel manganese antimonate as a stable water-oxidation catalyst in aqueous 1.0 M H2SO4

Low-temperature growth of highly crystallized transparent conductive fluorine-doped tin oxide films by intermittent spray pyrolysis deposition

https://publikationen.sulb.uni-saarland.de/bitstream/20.500.11880/24276/1/aeg199905.pdf

Comparison of spray pyrolyzed FTO, ATO and ITO coatings for flat and bent glass substrates

Abstract This paper presents an insight on major ion chemistry and identification of solute sources in meltwater of Chaturangi glacier throughout the ablation period 2015 and 2016. The results indicate that meltwater is slightly acidic with Ca–HCO 3 and Mg–HCO 3 dominated hydrochemical facies. In meltwater, Ca 2+ and HCO 3 − are the most dominant cation and anion, respectively. The Water Quality Index values show that the quality of meltwater is good for both the ablation seasons. An important factor governing the quality of water is the residence time for dissolving minerals from the rocks. Mineralogy of surrounding rocks and Gibbs plot suggest that the meltwater ionic concentration is mostly controlled by weathering of rocks with slight contribution from atmospheric aerosols. For meltwater, the average equivalent ratios of Na/Cl and K/Cl were calculated as 3.36 ± 1.29 and 2.29 ± 0.62 in 2015 and 1.39 ± 0.6 and 0.8 ± 0.2 in 2016, which are considerably higher than the marine aerosols (Na/Cl = 0.85 and K/Cl = 0.017), it also confirmed the less contribution of atmospheric input in meltwater. The petrographic analysis of surrounding rocks indicate positive relationship among the cations (Ca 2+ , Mg 2+ , Na + and K + ) and mineral abundance. Our observations suggest that the bedrock mineralogy and weathering reactions together with amount and composition of atmospheric inputs are the main sources of ions, dissolved in the glacier meltwater. It might be due to rate of chemical reaction which leads decomposition of rocks and leaching of minerals into the meltwater. Additionally, the geology of the area plays a significant as the influence of geology and climate on water quality is observed by the quantity and types of dissolved materials and amount of the sediment carried by the streams. The elevated proportion of Ca + Mg in total cations and high Ca + Mg/(Na + K ratios, 1.47 ± 0.14 in the year 2015 and 1.44 ± 0.28 in 2016 clearly reveal that the ionic composition is primarily controlled by carbonate weathering and partly by silicate weathering. Further, the low Na + K/TZ − ratio (0.41 ± 0.02) and (0.22 ± 0.05) in 2015 and 2016, respectively also supports that carbonate weathering is main geochemical process controlling the hydrochemistry of meltwater. In addition, the ion denudation rate was calculated for both the years. The results show that the cation denudation rate of meltwater was 32.84 and 22.30 ton/km 2 /ablation during 2015 and 2016, respectively, whereas the anion denudation rate was found to be 205.43 in 2015 and 170.24 ton/km 2 /ablation in 2016. 

/pdf/hydrogeochemical-analysis-and-identification-of-solute-22f4xeui.pdf

Hydrogeochemical analysis and identification of solute sources in the meltwater of Chaturangi glacier, Garhwal Himalaya, India

Grain size analysis is an essential tool for classifying sedimentary environments. The main aim of the current research is to use granulometric analysis of the Bhikiysain palaeolake sequence along the Ramganga river to describe changes in the depositional environment within the lake during the late Quaternary. The granulometric analysis was conducted using a laser particle size analyser on 32 samples, collected at 10 cm intervals in a vertical palaeolake profile, at Bhikiyasain (Ramganga Basin). The results of the grain-size analysis indicate that the size distribution of the sediment is unimodal. The unimodal size distribution of the sediment suggests that the sediment was supplied via fluvial action. The Bhikiyasain Basin (29°43.106’ N; 79°15.682’ E) underwent tectonic activity around 44 ka, resulting in the ponding of the Ramganga river and the formation of palaeolake deposit. Based on grain size analysis, variation in the colour and lithofacies, the entire profile has been divided into 6 different zones (zones 1 to 6). The silt has the highest concentration in all the zones except for zones 1 and 3. Zones with high silt concentration are inferred to represent low energy depositional environments during the time of deposition. The higher amount of sand concentration in zones 1 and 3 represent higher energy depositional environment. For the whole profile, the sorting of the samples varies between 1.1 and 2.0, indicating poor sorting of the samples. The poorly sorted sediment in all six zones represents limited transportation of sediment from the catchment and also suggests that the sediment was deposited in a low energy environment. The ternary plots also signify the dominance of silt followed by sand and clay. The skewness values range from 0.1 to 0.5 which indicates that the samples are symmetrical to very finely skewed. Variability in the skewness values may be due to changes in the intensity of wind and hydrodynamic conditions of the lake. The kurtosis value ranges from 0.9-1.4, indicating the samples are platykurtic, leptokurtic and mesokurtic in nature. Variability in the kurtosis may be due to changes in the flow characteristics of the depositional medium.

H. Bisht

Papers

Comparison of spray pyrolyzed FTO, ATO and ITO coatings for flat and bent glass substrates

Hydrogeochemical analysis and identification of solute sources in the meltwater of Chaturangi glacier, Garhwal Himalaya, India

Palaeoenvironmental Reconstruction Through Granulometric Analysis of a Palaeolake Deposit at Bhikiyasain, Kumaun Lesser Himalaya