Influence Of Bath Temperature Research Articles

Bath temperature impact on morphological evolution of Ni(OH)2 thin films and their supercapacitive behaviour

Nanostructured Ni(OH)2 thin films were deposited over stainless steel (SS) and glass substrate via simple chemical bath deposition (CBD) method. NiCl2:6H2O were used as source of nickel and aqueous ammonia as a complexing agent. The coating process of Ni(OH)2 material over substrate is based on the decomposition of ammonia complexed nickel ions at two different bath temperatures. The changes in structural, morphological and electrochemical properties are examined as an impact of bath temperature. XRD studies reveal formation of mixed phase of α and β at lower bath temperature (313 K) while, pure β phase of Ni(OH)2 thin films deposited was observed at higher bath temperature (353 K). The morphological evolution from honeycomb structure to vertically aligned flakes over the substrate is observed as the influence of bath temperature. The supercapacitive performance based on the morphology examined by using cyclic voltammetric measurements in 1 M KOH. The maximum specific capacitances of 610 and 460 F/g were observed for the vertical flake and honeycomb structured Ni(OH)2 thin films, respectively.

Influence of bath temperature on zinc plating and passivation process

Zinc films were prepared by a typical chloride zinc system electrodeposition on iron substrate. Effects of different temperatures on deposition rate, structures and surface morphology of zinc films were investigated in the paper. Trivalent chromium passivation technology was also studied in the paper to improve corrosion resistance of zinc films. Higher temperature could dramatically improve bath conductivity, which contributed directly to the rise in mass transfer and deposition rate. The deposited films were crystalline and showed characteristic peaks of zinc. However, zinc films with bad crystallinity would be obtained at higher temperatures due to thermal decomposition of additives. With the increase in temperature, zinc films with rough surface could be observed. Zinc passivation layer with optimal corrosion resistance could be obtained at passivation time of 30 s, temperature of 303 K and pH 3.

Influence of Bath Temperature on the Properties of In2S3 Films Grown by Chemical Bath Deposition

In2S3 films were deposited by chemical bath deposition (CBD) method on glass substrates using indium sulphate and thioacetamide (TA) as precursors and acetic acid as the complexing agent. The films were grown by varying the bath temperature (Tb) from 50°C to 90°C, keeping concentration of indium precursor at a constant value of 0.025M and thioacetamide concentration at 0.1M for a fixed deposition time of 60min. X-ray diffraction (XRD) studies revealed that the deposited films were nanocrystalline in nature and showed the (311) peak as preferred orientation, exhibiting cubic structure. The Raman studies revealed that the grown layers were free from secondary phases. The scanning electron microscopy (SEM) studies indicated smooth morphology at lower temperatures that changed in to granular structure at higher temperatures. Energy dispersive X-ray analysis (EDAX) revealed a change of composition from sulfur deficient to sulfur rich at a bath temperature of 70°C. The optical measurements showed that the films had a maximum transmittance of >85% in the visible region. The evaluated energy band of the layers varied in the range,<remove-image> 2.36 2.74eV with the change of bath temperature. A detailed study of the results were presented and discussed.

Studies on oscillating chemical reaction in Cu(II)‐catalyzed thiocyanate–hydrogen peroxide–NaOH system using pulsating sensor

AbstractWe present a novel measurement technique to study an oscillating chemical reaction using a new class of sensor, viz. a pulsating sensor developed in‐house. A halogen‐free oscillating chemical reaction in the Cu(II)‐catalyzed H2O2‐KSCN–NaOH system reported by Orban was chosen to examine the performance of this technique. Shift in potential during the oscillating reaction was captured online with high precision and excellent resolution using this simple but high‐performance pulsating potentiometric measurement technique. In this work, the influence of bath temperature and flow rate of reagents on the Cu(II)‐catalyzed H2O2–KSCN–NaOH oscillating chemical reaction is investigated to optimize the conditions for rapid oscillations. This, in turn, helps to evolve analyte pulse perturbation techniques for rapid assay of hydrazine, uranium(VI), and sodium thiosulfate in aqueous solutions using the above oscillating reaction. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 45: 19–29, 2013

SYNTHESIS OF PbSe THIN FILM BY CHEMICAL BATH DEPOSITION AND ITS CHARACTERIZATION USING XRD, SEM AND UV-Vis SPECTROPHOTOMETER

Lead selenide thin films were prepared by chemical bath deposition method using aqueous of lead nitrate, sodium selenate and sodium tartrate. The influence of bath temperature towards the properties of the thin films was studied. The films were characterized by X-ray diffraction, scanning electron microscopy and UV-Vis spectrophotometer. The XRD results confirmed the polycrystalline cubic structure of PbSe films. The intensity of major peak at 2ϴ = 25.1&deg; which belonged to (111) plane of PbSe, increased with bath temperature from 40 to 80 &deg;C. The SEM micrographs showed that the most homogeneous surface and larger grain sizes could be seen for the films deposited at 80 &deg;C as compared with other bath temperatures. Keywords: lead selenide, semiconductor, chemical bath deposition, thin films

Influence of Bath Temperature, Deposition Time and S/Cd Ratio on the Structure, Surface Morphology, Chemical Composition and Optical Properties of CdS Thin Films Elaborated by Chemical Bath Deposition

Cadmium sulphide (CdS) thin films were deposited on glass substrates by the chemical bath deposition (CBD) method, using anhydrous cadmium chloride (CdCl2) and thiourea (CS(NH2)2) as sources of cadmium and sulphur ions respectively. The influence of bath temperature (Tb), deposition time (td) aSnd [S]/[Cd] ratio in the solution on the structural, morphological, chemical composition and optical properties of these films were investigated. XRD studies revealed that all the deposited films were polycrystalline with hexagonal structure and exhibited (002) preferential orientation. The films deposited under optimum conditions (Tb = 75?C, td = 60 min and [S]/[Cd] ratio = 2.5) were relatively well crystallized. These films showed large final thickness and their surface morphologies were composed of small grains with an approximate size of 20 to 30 nm and grains grouped together to form large clusters. EDAX analysis revealed that these films were nonstoichiometric with a slight sulphur deficiency. These films exhibited also a transmittance value about 80% in the visible and infra red range.

Influence of bath temperature and bath composition on Co–Ag electrodeposition

A study of the best conditions to prepare smooth heterogeneous Co–Ag films with low amounts of S from a thiourea-based electrolytic bath has been performed. Using a 0.01 M AgClO 4 + 0.1 M Co(ClO 4) 2 + 0.1 M thiourea + 0.1 M sodium gluconate + 0.3 M H 3BO 3 + 0.1 M NaClO 4 bath, low temperature (10 °C) allowed obtaining compact and smooth deposits containing 2 wt.% sulphur. Decreasing thiourea content 0.06 M and increasing gluconate concentration up to 0.3 M, better deposits (more compact with lower sulphur content (1.2 wt.%)) were obtained. A clear influence of the species present in the bath on the film quality was observed: while gluconate favoured film cohesion, boric acid hindered hydrogen adsorption. For all films, fcc-Ag, hcp-Co and hcp-CoAg 3 phases were always detected by XRD, TEM and electron diffraction, their proportions varying with the electrodeposition conditions. Magnetic measurements revealed that the increase in the CoAg 3 led to an increase in the film coercivity. GMR values were only measured at cryogenic temperatures, they being higher for the deposits with the lowest sulphur content revealing that sulphur exerts a negative effect on magnetoresistance.

Electro-deposition and characterizations of nickel coatings on the carbon–polythene composite

Nickel coating on the carbon-polythene com- posite plate was prepared by electrodeposition in a nickel sulfate solution in this work. The morphology and cross- sectional microstructure of the nickel coating were exam- ined by scanning electron microscope (SEM) and optical microscope (OM), respectively. The influence of bath temperature on the nickel deposition rate was investigated experimentally. The adhesion between the coating and the substrate was evaluated by the pull-off test. The corrosion behavior of the coating in an aqueous solution of NaCl was studied by electrochemical methods. The results showed that the nickel electrodeposition rate could reach up to 0.68 lm min -1 on average under conditions of cathodic current density of 20 mA cm -2 and bath temperature of 60 C. It was confirmed that increasing the bath tempera- ture up to 50 C had a positive effect on the nickel deposit rate, while an adverse effect was observed beyond 60 C. The adhesion strength between the nickel coating and the substrate can be more than 2.3 MPa. The corrosion potential of the bright coating in the NaCl solution was more positive than that of the dull coating, and the anodic dissolution rate of the bright coating was also far lower at the same polarization potential compared with the dull

Preparation and Microstructural Studies of Electrodeposited FeSe Thin Films

Iron selenide (FeSe) thin films were electrodeposited onto tin oxide coated conducting glass substrates using aqueous solution mixture containing FeSO4 and SeO2 at various bath temperatures and deposition potentials. The deposited films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis by x-rays (EDX) for their structural, morphological and compositional properties. X-ray diffraction patterns revealed that the deposited films are found to be tetragonal structure with preferential orientation along (100) plane. The x-ray line profile analysis technique by the method of variance has been used to evaluate the microstructural parameters such as, crystallite size, R.M.S strain, dislocation density and stacking fault probability. The influence of bath temperature and deposition potential on the microstructual parameters was investigated. The SEM observation reveals uniform surface morphology for films deposited at higher bath temperatures. The experimental observations are discussed in detail.

Geometrical phases of excitonic qubits in quantum dots

We investigate the influence of phonon mediated interactions on the non-unitary evolutionof geometrical phases in excitonic qubits formed in quantum dots entangled by pure Förstercoupling. We consider decoherence to occur via acoustic phonons interacting through thedeformation potential and piezoelectric coupling mechanisms. The influences of bathtemperature, external electric field, quantum dot size and interdot distance on theevolution of geometrical phases are examined for the GaAs/AlGaAs material system. Weextend the theory to determine the effect of dynamic decoupling employing ultrafastπ-pulses on the evolution of geometrical phases in the presence of dephasing processes.

Influence of growth process on the structural, optical and electrical properties of CBD-CdS films

The hexagonal cadmium sulphide (CdS) thin films with strong (002) orientation are successfully prepared by chemical bath deposition (CBD) technique using the reaction between CdCl 2 and CS(NH 2) 2. Especially, polyglycol is used to modify the CBD system without magnetic agitation. The influence of bath temperature on the properties of the CdS films such as optical transmission, surface morphology and the structure is researched. The results show that polyglycol can flatten the films and diminish the pinhole. X-ray diffraction (XRD) and transmission electron microscopy (TEM) tests verify that the deposited CdS films presented a hexagonal structure and no secondary or mixed phases are found. A preferential columnar growth parallel to the substrate edge is also observed. It is found that the bath temperature plays a vital role on the quality of the CdS films. The increase of bath temperature improves the surface morphology of the CdS films and also diminishes pinholes on the films. The optimum bath temperature is 85 °C. The band gap calculated from transmission spectra is about 2.56–2.336 eV.

Electrodeposited cadmium selenide films for solar cells

We have conceived this paper according to our background and interest in the preparation and photoelectrochemistry of II–VI semiconductor thin films. The synthesis of polycrystalline CdSe thin films by cathodic electrodeposition on conducting substrates is described. Electrodeposition involves potentiostatic reduction from an acid aqueous bath. The influence of bath temperature and deposition potential on the crystallinity is discussed. For optimized deposition parameters, the XRD patterns reveal cubic and hexagonal CdSe. Electron probe microanalysis shows an excess of Se in the samples. Photoelectrochemical studies of the films in aqueous polysulfide allowed us to determine the photovoltaic properties e.g: semiconducting type, short-circuit current, open circuit voltage and fill factor. Cet article a été conçu en se basant sur les acquis et les intérêts dans la préparation et la photoélectrochimie des couches minces semiconductrices de la famille II–VI. Des couches minces de CdSe polycristallin ont été élaborées par électrodéposition cathodique en milieu acide sur des substrats conducteurs. L'influence de la température du bain et du potentiel de déposition sur la cristallinité a été discutée. L'analyse par diffraction des rayons X des couches de CdSe révèlent une cristallisation dans les deux structures cubique et hexagonale. La Microanalyse (MEB) montre un excès de Se dans les échantillons. Les études photoélectrochimiques ont permis de determiner le type du semiconducteur, le courant de court- circuit, la tension de circuit ouvert et le facteur de forme.

A Study on the Anode Effect in KF-2HF System. III. Influence of Bath Temperature and Surface Tension and Addition of Fluoride Particles on the Occurrence of the Anode Effect

Abstract The decomposition reaction of the graphite fluoride film formed on the edge plane of pyrolytic graphite, carbon, and graphite electrodes was faster in a KF·HF bath (250 °C) than in a KF·2HF bath (100 °C) due to the higher temperature of KF·HF bath. The critical current densities (CCD’s) were about 0.1 A/cm2 for the layer and edge planes of pyrolytic graphite, carbon, and graphite electrodes in the KF·HF bath, and the CCD for each electrode was larger in the KF·HF bath than in the KF·2HF bath. The anode effect took place easily on the glassy carbon electrode in the KF·2HF bath. However, the anode effect did not take place in liquid hydrogen fluoride due to its very low surface tension, although the graphite fluoride film was formed on the electrode surface. The zeta-potential of aluminum fluoride particles in liquid hydrogen fluoride containing 0–20 mol of potassium fluoride/1 and that of magnesium fluoride particles in liquid hydrogen fluoride were almost zero at 0 °C. From the results it is not proper that the effect of the addition of dispersed particles upon the anode effect is explained by the view of electrostatic force of the particles proposed so far.

Effect of bath temperature on the chemical bath deposition of PbSe thin films

PbSe thin films are prepared by chemical bath deposition technique over microscope glass substrates from an aqueous acidic bath containing lead nitrate and sodium selenate. The influence of bath temperature on the properties of PbSe film is investigated. The X-ray diffraction analysis showed the deposited films were polycrystalline and having the (111) orientation. The surface morphology study revealed that the grains have cubic shape crystal. The band gap energy was decreased from 2.0 to 1.3 eV as the bath temperature was increased from 40 to 80°C. The films deposited at 80°C showed good crystallinity and uniformly distributed over the surface of substrate with larger grain sizes. Therefore, the optimum bath temperature is 80°C. Keywords: Lead selenide; X-ray diffraction; Band gap energy; Chemical bath deposition; Thin films DOI: 10.3126/kuset.v6i2.4021Kathmandu University Journal of Science, Engineering and Technology Vol.6. No II, November, 2010, pp.126-132

An X-Ray Study on the Micro Strain and the Coherently Diffracting Domain Size in Electrodeposited Chromium

It is recognized that electrodeposits are similar in microstructure to the microcrystals produced by cold work and the crystals with high internal stress and preferred orientation.In order to obtain the knowledge of microstructures in chromium, electrodeposited from a chromic acid plating bath as a function of bath temperature, the X-ray diffraction line profiles of its deposits were analysed by Fourier series method which was practicable by using a single reflection only. The information on micro strain, coherently diffracting domain size was obtained from the Fourier cosine coefficients. Moreover, the effect of unresolved Kα line profile and Kα1 line profile separated by Rachinger's graphical method on the r.m.s. strain and the domain size were examined. From the experimental results, the following conclusions have been derived.(1) The value of r.m.s. strain obtained by using unresolved Kα line profile is a little larger than that in the case of Kα1 diffraction line profile separated by Rachinger's graphical method, but the domain she is slightly small in the case where unresolved Kα line profile was used.(2) It is found that the r.m.s. strains in electrodeposited chromium analysed on the (211) diffraction line profiles have decreased with increasing bath temperatures, in the range of 40 to 70°C, and again increased at 75°C. The influence of bath temperature on the stored energy and the dislocation density derived from the mean squared strain show a similar tendency as the r.m.s. strain. The coherently diffracting domain size in electrodeposited chromium on the (211) diffraction line profile has increased with increasing bath temperature, in the range of 40 to 70°C, and again decreased at 75°C.(3) The reflecting plane dependence of the r.m.s. strain and the domain size in electrodeposited chromium obtained from bath temperature of 60°C have been investigated on the three planes of (110), (200) and (211). It is found that the r.m.s. strain has increased in the order (200), (211), (110) and the domain siza in (211) plane is smaller than that in the case of (110) and (200) planes, but between the domain size in (110) and (200) planes, no marked difference has been recognized.