scholarly journals Voltammetric growth of tin oxides in borate solution of pH 8.7

2017 ◽  
Vol 7 (2) ◽  
pp. 65
Author(s):  
Tiago Brandão Costa ◽  
Tania Maria Cavalcanti Nogueira ◽  
Ladário Da Silva
Keyword(s):  
Film Growth ◽  
Sweep Rate ◽  
Ex Situ ◽  
Phosphate Solution ◽  
Buffer Solution ◽  
Charge Densities ◽  
Tin Oxides ◽  
Phosphate Solutions ◽  
Tin Oxide Films ◽  
Borate Solution

<p class="PaperAbstract"><span lang="EN-US">Voltammetry has been employed to study the growth of tin oxides in buffer solution of 0.3 mol L<sup>-1</sup> H<sub>3</sub>BO<sub>3</sub> + 0.15 mol L<sup>-1</sup> Na<sub>2</sub>B<sub>4</sub>O<sub>7</sub>·10H<sub>2</sub>O (pH 8.7). Voltammetric data were compared with the results of tin in a phosphate solution of pH 8.7, presented in the previous work, in order to study the influence of these anions on the growth of tin oxides. The thicknesses of grown oxides were determined using ex-situ ellipsometric technique and the volume per charge unity of the film, V<sub>f</sub>, was calculated for different charge densities of the film. The results showed that less dense films were obtained at higher sweep rates. Tin oxide films grown in phosphate solution at 2 mV s<sup>-1</sup> were denser than those grown in borate solution at the same sweep rate. The kinetic parameters, determined applying the ohmic model, showed that there are no significant differences between the kinetics at the metal/film interface of tin in borate and tin in phosphate solutions. Despite these facts, the ionic specific resistivity for oxide film growth in borate solution were significantly higher than in phosphate solution. This result indicates that incorporation of anions occurs during the growth of the films.</span></p>

scholarly journals Ellipsometric measurement of thickness of tin oxides grown by voltammetry in phosphate solution of pH 8.7

2016 ◽  
Vol 6 (4) ◽  
pp. 303
Author(s):  
Tiago Brandão Costa ◽  
Tania Maria Cavalcanti Nogueira ◽  
Ladário Da Silva
Keyword(s):  
Charge Density ◽  
Tin Oxide ◽  
Oxide Films ◽  
Galvanized Steel ◽  
Ex Situ ◽  
Phosphate Solution ◽  
Buffer Solution ◽  
Tin Oxides ◽  
Ionic Resistivity ◽  
Tin Oxide Films

<p class="PaperAbstract"><span lang="EN-US">The voltammetry induced growth of tin oxides on tin in the buffer solution of 0.18 mol L<sup>-1</sup> Na<sub>2</sub>H<sub>2</sub>PO<sub>4</sub> and 0.18 mol L<sup>-1</sup> KH<sub>2</sub>PO<sub>4</sub> (pH 8.7) has been studied. Ex-situ ellipsometric mea­surements were made in an order to determine thicknesses of the grown oxides. From these results the film volume per charge unit, </span><span lang="EN-US">V</span><sub><span lang="EN-US">f</span></sub><span lang="EN-US">, was calculated for different charge den­sities of the film. This parameter was used to calculate the variable ionic resistivity of the film, </span><span lang="EN-US">ρ</span><sub><span lang="EN-US">f</span></sub><span lang="EN-US">, considered by the Ohmic model for the case of voltammetric growth of oxides on metals having a previously existing continuous film. Tin oxide films grown at 2 mV s<sup>-1</sup> showed to be less dense for values of charge density below 50 C m<sup>-2</sup>, having </span><span lang="EN-US">V</span><sub><span lang="EN-US">f</span></sub><span lang="EN-US"> near <br /> 5.7x10<sup>-10</sup> m<sup>3</sup> C<sup>-1</sup>. For higher values of charge density, tin oxide films become denser, having </span><span lang="EN-US">V</span><sub><span lang="EN-US">f</span></sub><span lang="EN-US"> near 0.5x10<sup>-10</sup> m<sup>3</sup> C<sup>-1</sup>. The calculated values of the variable ionic resistivity of the film during voltammetric growth showed that </span><span lang="EN-US">ρ</span><sub><span lang="EN-US">f</span></sub><span lang="EN-US"> passes through a minimum (justifying the maximum in current densities). This behavior was also found by other authors in the cases of Zn, Nb, Ni and galvanized steel sheets.</span></p>

Composition and Structure of Epitaxial CaF2 Layers at the First Stages of Their Growth on Si(111)

2001 ◽  
Vol 696 ◽  
Author(s):  
R. Würz ◽  
W. Bohne ◽  
W. Fuhs ◽  
J. Röhrich ◽  
M. Schmidt ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Stoichiometric Composition ◽  
Interface Reaction ◽  
Heavy Ion ◽  
Interface Layer ◽  
Buffer Layers ◽  
Ex Situ ◽  
Elastic Recoil ◽  
Detection Analysis

AbstractCaF2 films with thicknesses in the monolayer range (<20 Å) were grown on Si(111) by evaporation from a CaF2 source at UHV conditions. They were characterized ex-situ by Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA), RBS/Channeling, X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). The F/Ca ratio of the films was found to depend on the growth temperature Ts and to deviate appreciably from the stoichiometric composition (F/Ca=2). Due to an interface reaction which leads to a CaF-interface layer a change from polycrystalline to epitaxial growth occurs at Ts=450°C. At higher temperature film growth started with a closed layer of CaF on top of which CaF2 layers with an increasing fraction of pinholes were formed. By means of a two-step process at different temperatures, the amount of pinholes could be strongly reduced. It was found, that buffer layers of CaF2 with a CaF interface layer introduced in Au/p-Si contacts enhance the barrier height by as much as 0.36eV to values of 0.64eV.

Growth of Oriented Tin Oxide Thin Films from an Organctin Compound by Spray Pyrolysisxf

1992 ◽  
Vol 271 ◽  
Author(s):  
Isao Yag ◽  
Shoji Kaneko
Keyword(s):  
Electron Microscopy ◽  
Tin Oxide ◽  
Film Growth ◽  
Growth Parameters ◽  
Optimum Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tin Oxide Films ◽  
Heated Glass ◽  
Scanning Electron

ABSTRACTTin oxide films were grown from di-n-butyltin diacetate on a heated glass substrate by a pneumatic spraying system The effects of various film growth parameters. i.e solvent, solution feed rate, film thickness, and film growth rate on the microstructures of the films were studied by X-ray diffraction and scanning electron microscopy The SnO2 films of the (200) plane were grown by the optimum growth parameters

The crossover of preferred orientation in TiN film growth: A real time x-ray scattering study

1997 ◽  
Vol 12 (1) ◽  
pp. 9-12 ◽  
Author(s):  
J. H. Je ◽  
D. Y. Noh ◽  
H. K. Kim ◽  
K. S. Liang
Keyword(s):  
Real Time ◽  
Film Growth ◽  
Substrate Surface ◽  
Rf Sputtering ◽  
Growth Front ◽  
Surface Topology ◽  
Ex Situ ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

The orientational crossover phenomena in a radio-frequency (rf) sputtering growth of TiN films were studied in a real-time synchrotron x-ray scattering experiment. Following the initial random nucleation and growth stage, the growth was dominated by the grains with the (002) planes aligned with the substrate surface. Surprisingly, at later stages, the grains with the (002) growth front tilted away from the surface by about 60° became dominant. The tilting of the growth front resulted in a faceted surface topology that was confirmed by an ex situ AFM study. Our x-ray results suggest that the crossover was driven by the competition between the surface and the strain energy

scholarly journals The Estimation of Acidic Behavior of Wood by Treatment with Aqueous Solution

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Güneş Uçar ◽  
Mualla Balaban Uçar
Keyword(s):  
Aqueous Solution ◽  
Wood Species ◽  
Ph Value ◽  
Phosphate Solution ◽  
Weak Acids ◽  
New Approach ◽  
Conjugate Acid ◽  
Phosphate Solutions

As a new approach, the acidity that wood exhibits under moderate conditions is assayed by stimulated dissociation of weak wood acids in lightly basic secondary phosphate solutions. To assure a sufficient dissociation of hardly soluble weak acids in the solution, the amount of wood suspended in solutions should be small but vary depending on the degree of acidity of wood species. However, the difficulties are associated with the titration of very dilute acids limiting the precision of the measurement. If the disintegrated wood is suspended in a secondary phosphate solution, the weak woods acids form the conjugate acid from secondary phosphate resulting in a pH fall of the solution. The decrease in the pH value in phosphate solution, which depends on the wood acidity, can be evaluated to estimate the acidity arising from wood under moderate conditions.

Heteroepitaxy of Ge on Vicinal Si(100)

1990 ◽  
Vol 198 ◽  
Author(s):  
Mohan Krishnamurthy ◽  
Jeff S. Drucker ◽  
J.A. Venables
Keyword(s):  
Intermediate Layer ◽  
Room Temperature ◽  
Secondary Electron ◽  
Elevated Temperatures ◽  
Film Growth ◽  
Growth Parameters ◽  
Ex Situ ◽  
Nucleation Density ◽  
Size Distributions ◽  
Surface Steps

ABSTRACTThe initial stages of germanium heteroepitaxy on vicinal Si(100) have been studied using in-situ deposition in a UHV STEM. Germanium was deposited using molecular beam techniques onto substrates misoriented 1° and 5* toward <110> held at room temperature, 375°C and 525°C. Film thicknesses were in the range 4-6 ML, just greater than the stable intermediate layer of 3-4ML (1ML = 0.14nm). The Ge clusters were observed using biassed secondary electron (b-SE) imaging with nanometer resolution. Comparisons were made between deposition at the elevated temperatures, and room temperature deposition followed by anneals at the same temperatures.Annealing the low temperature deposits produces coarsening of the islands which is similar on the 1° and 5° samples. Island size distributions and other film growth parameters obtained from the 375°C and 525°C anneals indicate that the coarsening is different at these temperatures and is possibly affected by instabilities in the intermediate layer. Results of the high temperature depositions indicate that neither surface steps nor the edges of islands act as perfect sinks, and that diffusion distances are of the order of several microns. The nucleation density and size distributions are markedly different for deposition at 375°C and 525°C possibly due to competitive capture at strong sinks.In a parallel set of experiments in a standard UHV chamber, macroscopic wafer samples were analyzed with RHEED, Auger and secondary electron spectroscopy. These correlate well with the intermediate layer thicknesses previously reported in the literature, and the large contrast observed in the b-SE images. Ex situ TEM studies of samples grown in this chamber show islands with various contrast features including those of coherent strain.

scholarly journals Зависимость топологии эпитаксиальных слоев PbSnTe:In от концентрации In

2021 ◽  
Vol 91 (6) ◽  
pp. 1038
Author(s):  
Д.В. Ищенко ◽  
А.Н. Акимов ◽  
И.О. Ахундов ◽  
В.А. Голяшов ◽  
А.Э. Климов ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Epitaxial Films ◽  
Ex Situ ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Tin Telluride ◽  
Lead Tin Telluride ◽  
Statistical Indicators

The topology of the surface of epitaxial films of lead tin telluride solid solution, including those with the addition of indium (Pb1-xSnxTe:In), grown on single-crystal BaF2 (111) substrates and a CaF2/BaF2 buffer layer on Si (111) was studied by atomic force microscopy. It is shown that the characteristic statistical indicators of the relief are due to the peculiarities of film growth and the mechanism of incorporation of Indians, the excess content of which was registered on the surface ex situ by X-ray photoelectron spectroscopy.

scholarly journals Effects of Chemical Mutagen (Sodium Azide) on Onion Grown in Organic and Inorganic Fertilized Soil

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Adeoti O.M. ◽  
Sodiq Zainab O ◽  
Adeoye K.A
Keyword(s):  
Sodium Azide ◽  
Phosphate Buffer Solution ◽  
Organic Fertilizers ◽  
Stem Length ◽  
Phosphate Solution ◽  
Chemical Agent ◽  
Buffer Solution ◽  
Green House ◽  
Fertilized Soil ◽  
Laboratory Technology

The effects of chemical agent (Sodium Azide) on Onion growing in organic and inorganic fertile soil was to be examined during this study. The analysis work was carried out within the green house of the research laboratory technology of the Oke Ogun Science Laboratory Technology, Saki, Oyo State. Onion seeds were soaked inside different beakers containing the mixture of Sodium Azide and water mixed with 10 ml of Phosphate solution for 4 hours. Also, the control was soaked with normal water and 10 ml of Phosphate buffer solution. The treated seeds of onions was planted in plastic containers containing 4.2 g of weighed humus soil within the green house at the Department of research lab Technology of The Oke Ogun polytechnic school, Saki Oyo State. The samples parameter were taken daily for six consecutive months. The result obtained was additionally subjected to statistical analysis by using DMRT techniques. The results showed that the stem length was ranged from 11.39±0.62 and 9.98±0.52 with sample of onion without sodium Azide and inorganic had the highest stem length values and samples of onion with Sodium Azide and inorganic had very cheap stem length. However, the leave length ranged from 29.63±0.12 and 22.45±0.10 with the Onion samples with inorganic and Organic fertilizers which had the highest leave length and sample of onion without Sodium Azide was very low leave length. The results of this study showed that each one the parameters studied within the plant were low with Sodium Azide treatment. The decrease in plant growth, plant heights, root lengths, and Phaonerogam survival, fruit yield per plant and height at maturity with agent concentration. It is hereof suggested that Sodium Azide (NaN3) was expected to produce mutation in onion that area unit extremely liable to harmful pathogens and making them cheap to be useful for farmers.

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