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Article
Publication date: 1 August 1970

R.W. Wilson and E.B. Shone

AN OVERLAY bearing is a bearing with a precision electroplated overlay of lead‐tin or lead‐indium alloy, 20 to 40µ thick. This lead‐alloy overlay is generally applied to a…

Abstract

AN OVERLAY bearing is a bearing with a precision electroplated overlay of lead‐tin or lead‐indium alloy, 20 to 40µ thick. This lead‐alloy overlay is generally applied to a copper‐lead or lead‐bronze substrate, which is itself bonded to a steel backing. Bearings of this construction are probably the most extensively used type of engine bearings; many millions are manufactured annually. The main functions of the overlay are to provide a seizure‐resistant surface, to increase the tolerance of the bearing for dirt and wear‐debris, and to protect the lead in the underlying copper‐lead or lead‐bronze alloy from corrosion by oxidized oil. When mineral oils are exposed to air oxidation for prolonged periods at elevated temperatures, weak organic acids are formed which can dissolve pure lead. The lead in copper‐lead or lead‐bronze is present as a separate, unalloyed phase, very susceptible to corrosion by weak organic acids. However, it has been known for some time that if lead is alloyed with indium or tin it is not corroded in this way. Most bearing manufacturers incorporate at least 4%w indium or 8%w tin in overlays to make them resistant to corrosion, but precise information on the amounts of alloying element required is not available.

Details

Anti-Corrosion Methods and Materials, vol. 17 no. 8
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 5 December 2017

Mohammadali Eslamian, Alireza Salehi and Zohreh Sadat Miripour

Indium tin oxide (ITO) thin film as a gas sensor has a good stability and performance. The purpose of this paper is to compare the effect of depositing different metal…

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Abstract

Purpose

Indium tin oxide (ITO) thin film as a gas sensor has a good stability and performance. The purpose of this paper is to compare the effect of depositing different metal layers in various structures on the gas sensing properties of ITO toward ethanol and carbon dioxide.

Design/methodology/approach

In this work, the authors have investigated the effect of depositing an ITO layer by Electron Beam Evaporation technique under, on top and in the middle of the metal layers. Surface morphology and the response of the fabricated sensors were compared and the changes in the response of the sensors to ethanol and carbon dioxide gases were studied at various gas concentrations and operating temperatures. The sensing mechanism and result of the other studies were also discussed.

Findings

Comparing various sensor structures reported in this study showed that the ITO nanorods which grow over distinct Ag nano-islands in the ITO/Ag structure has the highest response of 420 per cent to ethanol which is 6 times more than the single-layer ITO sensor. Further, gold nanoparticles on ITO nanorods in Au/ITO/Ag structure produce a very complex structure that exhibits the best response of 150 per cent to carbon dioxide which is 6.5 times more than the single-layer ITO sensor. The response and the recovery times were improved also.

Originality/value

Different ITO-metal gas sensor structures were studied and compared toward ethanol and carbon dioxide. Response enhancement and various surface changes through a series of experiments and analysis were discussed and compared to the literature.

Details

Sensor Review, vol. 38 no. 1
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 7 December 2020

Michał Mazur, Roman Pastuszek, Damian Wojcieszak, Danuta Kaczmarek, Jarosław Domaradzki, Agata Obstarczyk and Aneta Lubanska

Indium tin oxide (ITO) is a material belonging to the group of transparent conductive oxides, which are widely used in many fields of technology including optoelectronics…

Abstract

Purpose

Indium tin oxide (ITO) is a material belonging to the group of transparent conductive oxides, which are widely used in many fields of technology including optoelectronics and photovoltaics. However, the properties of ITO thin films depend on many factors. Therefore, the aim of the study was thorough investigation of the properties of sputtered ITO thin films of various thicknesses.

Design/methodology/approach

ITO coatings were deposited by magnetron sputtering in pure argon atmosphere using ceramic ITO target. Various deposition times resulted in obtaining thin films with different thickness, which had significant influence on the optoelectronic properties of deposited coatings. In this work the results of investigation of structural, surface, optical and electrical properties were presented.

Findings

Increase of the coating thickness caused change of the microstructure from amorphous to nanocrystalline and occurrence of grains with a size of 40 to 60 nm on their surface. Moreover, the fundamental absorption edge was red-shifted, whereas the average transmission in the visible wavelength range remained similar. Increase of the thickness caused considerable decrease of the sheet resistance and resistivity. It was found that even thin films with a thickness of 10 nm had antistatic properties.

Originality/value

The novelty and originality of presented work consists in, among other, determination of antistatic properties of ITO thin films with various sheet resistances that are in the range typical for dielectric and semiconducting material. To date, there are no reports on such investigations in the literature. Reported findings might be very helpful in the case of, for example, construction of transparent antireflective and antistatic multilayers.

Details

Circuit World, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 18 October 2011

Alex M. Andrew

The paper seeks to review the undesirable side‐effects of some measures to protect the environment, particularly the results of increased demand for certain metals used in…

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Abstract

Purpose

The paper seeks to review the undesirable side‐effects of some measures to protect the environment, particularly the results of increased demand for certain metals used in hybrid cars and wind turbines, and for tantalum for mobile phones. The increased demands for indium and lithium due to technical developments are also discussed although they do not pose corresponding dilemmas.

Design/methodology/approach

The aim is to review developments on the internet, especially those of general cybernetic interest.

Findings

Undesirable side‐effects need to be considered, though means of overcoming them are not always apparent.

Practical implications

In the case of tantalum and mobile phones, attention has been given to ethical sourcing. The possibility of indium extraction in the UK is a welcome development.

Originality/value

It is hoped this is a valuable periodic review.

Details

Kybernetes, vol. 40 no. 9/10
Type: Research Article
ISSN: 0368-492X

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Article
Publication date: 3 August 2015

Kazimierz Drabczyk, Jaroslaw Domaradzki, Piotr Panek and Danuta Kaczmarek

The purpose of this paper was the investigation of transparent conducting oxide (TCO) applied as an additional part of front metal electrode of crystalline silicon solar…

Abstract

Purpose

The purpose of this paper was the investigation of transparent conducting oxide (TCO) applied as an additional part of front metal electrode of crystalline silicon solar cell. Transparent conducting oxides are widely used as counter electrodes in a wide range of electronics and optoelectronics applications, e.g. flat panel displays. The most important optical and electrical requirements for TCOs are high optical transmittance and low resistivity. This low resistivity might invoke the possibility of increasing the distance between the fingers in the solar cell front electrode, thus decreasing the total area covered by metal and decreasing the shadowing loss.

Design/methodology/approach

In the present work, thin films of indium-tin-oxide (ITO) as a transparent counter electrodes, were evaporated on the surface of silicon n+-p junction structures used in solar cells. The influence of the properties of ITO electrode on the electrical performance of prepared solar cells was investigated through optical and electrical measurements. The discussion on the influence of deposition conditions of the TCO films on recombination of the photogenerated electrical charge carriers and solar cell series resistance was also included.

Findings

In this work, the fingers lines 100 μm width were screen-printed on the c-Si wafer with ITO layer. Monocrystalline silicon 25 cm 2,200-μm-thick wafers, were used for this testing. The usefulness of the ITO films as antireflection coating was discussed as well. It is commonly known that electrical performance of solar cells is limited by surface passivation. Despite this, the obtained results for ITO-Si structures showed relatively high value of short circuit current density (Jsc) up to 33 mA/cm2.

Originality/value

Our experiments confirmed the potential of application of ITO as anti-reflection coating (ARC) layer and according to their low resistivity possible use as a functional counter electrodes in photovoltaic structures.

Details

Microelectronics International, vol. 32 no. 3
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 1 April 2003

Jarmo Määttänen

The increasing demand for fine pitch interconnections has led to a growth of interest in anisotropically conductive adhesives (ACAs) as an alternative to solder joints in…

Abstract

The increasing demand for fine pitch interconnections has led to a growth of interest in anisotropically conductive adhesives (ACAs) as an alternative to solder joints in high density applications. The understanding of the conduction mechanisms for ACAs is of vital importance when choosing the right adhesive for a specific application. In the conductivity model, a formula has been created that can be used to estimate how the degree of deformation of the particles effects the resistance, especially in the case of soft metal‐coated polymer particles. Using this model, it is possible to estimate the total contact resistance. Some comparisons are made with real measurements for gold and indiumtinoxide (ITO) surfaces, using gold‐coated polymer particles and gold bumped chips. For gold surfaces, the measurements have shown reasonably good correlation with the model. In the case of the ITO surface, the interface resistances seem to be the major part of the total resistance.

Details

Soldering & Surface Mount Technology, vol. 15 no. 1
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 26 January 2021

Elakkiya A., Radha Sankararajan and Sreeja B.S.

The proposed metamaterial absorber (MMA) has the following advantages: first, the structure of the MMA consists of one planar metallic resonator, which presents a new…

Abstract

Purpose

The proposed metamaterial absorber (MMA) has the following advantages: first, the structure of the MMA consists of one planar metallic resonator, which presents a new design approach to obtain a multiband absorption response, rather than using multiple unit-cells in the one large unit cell or stacking different layers. Second, the simultaneous realization of triple-band and dual-band absorption (or bi-functional absorption) at five different frequencies can integrate the respective advantages of the triple functions of the triple-band MMA and double-band MMA, and therefore, the bi-functional MMA will find more application prospects than multiple-functional devices of triple-band and dual-band. Third, the authors simulated the three combinations of MMA here, which is indium tin oxide (ITO)-Polyimide-ITO, ITO-Teflon-ITO and ITO-polyethylene terephthalate (PET)-ITO for the same planar structure and achieve a high absorption rate. Finally, the proposed structure is polarization and angle independent in nature.

Design/methodology/approach

This absorption device consists of the top circular resonator, the middle insulating SiO2 medium layer and the bottom metallic copper ground plane placed on a substrate. The conductivity of the copper metal is s = 5.8 × 107 s/m. As the transmission of the MMA structure is zero, the substrate materials can be selected randomly. Totally four combinations of terahertz MMA are designed and simulated here which are ITO- SiO2 –ITO, ITO-Polyimide-ITO, ITO-Teflon-ITO and ITO- PET-ITO for the same planar structure.

Findings

Compared with previous MMAs, the proposed MMA has the following advantages: First, the structure of the MMA consists of one planar metallic resonator, which presents a new design approach to obtain a multiband absorption response, rather than using multiple unit-cells in the one large unit cell or stacking different layers. Second, the simultaneous realization of triple-band and dual-band absorption (or bi-functional absorption) at five different frequencies can integrate the respective advantages of the triple functions of the triple-band MMA and double-band MMA, and therefore, the bi-functional MMA will find more application prospects than multiple-functional devices of triple-band and dual-band. Third, the authors simulated the three combinations of MMA here, which is ITO-polyimide-ITO, ITO-Teflon-ITO and ITO- PET-ITO for the same planar structure and achieve a high absorption rate. Finally, the proposed structure is polarization and angle independent in nature.

Originality/value

First, the structure of the MMA consists of one planar metallic resonator, which presents a new design approach to obtain a multiband absorption response, rather than using multiple unit-cells in the one large unit cell or stacking different layers. Second, the simultaneous realization of triple-band and dual-band absorption (or bi-functional absorption) at five different frequencies can integrate the respective advantages of the triple functions of the triple-band MMA and double-band MMA, and therefore, the bi-functional MMA will find more application prospects than multiple-functional devices of triple-band and dual-band. Third, the authors simulated the three combinations of MMA here, which is ITO-polyimide-ITO, ITO-Teflon-ITO and ITO-PET-ITO for the same planar structure and achieve a high absorption rate. Finally, the proposed structure is polarization and angle independent in nature.

Details

Circuit World, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0305-6120

Keywords

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Article
Publication date: 1 October 2018

Boyang Qu, Peng Zhang, Jianmin Luo, Shie Yang and Yongsheng Chen

The purpose of this paper is to investigate a light-trapping structure based on Ag nanograting for amorphous silicon (a-Si) thin-film solar cell. Silver nanopillar arrays…

Abstract

Purpose

The purpose of this paper is to investigate a light-trapping structure based on Ag nanograting for amorphous silicon (a-Si) thin-film solar cell. Silver nanopillar arrays on indium tin oxide layer of the a-Si thin-film solar cells were designed.

Design/methodology/approach

The effects of the geometrical parameters such as nanopillar radius (R) and array period (P) were investigated by using the finite element simulation.

Findings

The optimization results show that the absorption of the solar cell with Ag nanopillar structure and anti-reflection film is enhanced up to 29.5 per cent under AM1.5 illumination in the 300- to 800-nm wavelength range compared with the reference cell. Furthermore, physical mechanisms of absorption enhancement at different wavelength range are discussed according to the electrical field amplitude distributions in the solar cells.

Research limitations/implications

The research is still in progress. Further studies mainly focus on the performance of solar cells with different nanograting materials.

Practical implications

This study provides a feasible method for light-trapping structure based on Ag nanograting for a-Si thin-film solar cell.

Originality/value

This study is promising for the design of a-Si thin-film solar cells with enhanced performance.

Details

Microelectronics International, vol. 35 no. 4
Type: Research Article
ISSN: 1356-5362

Keywords

Content available
Article
Publication date: 23 August 2011

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462

Abstract

Details

Circuit World, vol. 37 no. 3
Type: Research Article
ISSN: 0305-6120

Content available

Abstract

Details

Soldering & Surface Mount Technology, vol. 23 no. 3
Type: Research Article
ISSN: 0954-0911

1 – 10 of 197