Wyniki wyszukiwania - Biblioteka Nauki

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Structural and conductivity studies of LiNi0.5Mn0.5O2 cathode materials for lithium-ion batteries

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Murali N. , Babu K. V. , Babu K. E. , Veeraiah V.

Materials Science Poland

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2016

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tom Vol. 34, No. 2

404--411

EN

Layered oxide LiMO2 (Ni, Co, Mn) have been proposed as cathode materials for lithium-ion batteries. Mainly LiNiO2 is accepted as an attractive cathode material because of its various advantages such as low cost, high discharge capacity, good reversibility. The LiNi0.5 Mn0.5 O2 powders are synthesized by a sol-gel method using citric acid as a chelating agent. The structure of the synthesized material is analyzed by using XRD, FT-IR and the microstructures of the samples are observed by using FESEM. The intensities and positions of the peaks are in a good agreement with the previous results. The morphological changes are clearly observed as a result of manganese substitution. The Fourier transform infrared (FT-IR) spectra obtained with KBr pellet data reveal the structure of the oxide lattice constituted by LiO6 and NiO6 octahedra. The conductivity studies are characterized by (EIS) in the frequency range of 42 Hz to 1 MHz at room temperature to 120 °C. The dielectric properties are analyzed in the framework of complex dielectric permittivity and complex electric modulus formalisms. It indicates that the conductivity increases with increasing temperature. The fitting data of EIS plots replicate the non-Debye relaxation process with negative temperature coefficient of resistance (NTCR) behavior.

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Structural and optical characteristics of SnS thin film prepared by SILAR

88%

Mukherjee A. , Mitra P.

Materials Science Poland

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2015

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tom Vol. 33, No. 4

847--851

EN

SnS thin films were grown on glass substrates by a simple route named successive ion layer adsorption and reaction (SILAR) method. The films were prepared using tin chloride as tin (Sn) source and ammonium sulfide as sulphur (S) source. The structural, optical and morphological study was done using XRD, FESEM, FT-IR and UV-Vis spectrophotometer. XRD measurement confirmed the presence of orthorhombic phase. Particle size estimated from XRD was about 45 nm which fitted well with the FESEM measurement. The value of band gap was about 1.63 eV indicating that SnS can be used as an important material for thin film solar cells. The surface morphology showed a smooth, homogenous film over the substrate. Characteristic stretching vibration mode of SnS was observed in the absorption band of FT-IR spectrum. The electrical activation energy was about 0.306 eV.

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Characterization of laser ablated AgInSe2 films

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Pathak D. , Bedi R. K. , Kaur D.

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tom Vol. 28, No. 1

199--205

EN

AgInSe2 (AIS) thin films have been grown directly on silicon by means of a pulsed laser deposition technique. The X-ray diffraction studies show that the films are textured in the (112) direction. Increase of the substrate temperature results in a more ordered structure. Composition of the samples has been analysed by EDAX. It was found that the stoichiometry is better maintained with the PLD technique than with other traditional methods like thermal evaporation. The optical studies of the films show that the optical band gap is about 1.20 eV. The results of investigations may be of interest for a better understanding of the growth processes of chalcopyrite thin films on silicon materials.

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Influence of Particle Size and Load on Loss of Material in Manganese-Steel Material: an Experimental Investigation

88%

Sinha R. , Mukhopadhyay A. K.

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tom Vol. 63, iss. 1

359--364

EN

The present study explores the influence of variables like particle size of coal, load, speed and sliding distance on weight loss in manganese-steel (Mn-steel). The observations are made using pin-on-disc apparatus. Specimen prepared from Mn-steel used for the wear test. The size and shape of specimen is in accordance with ASTM G99 standard. From design of experiment (DOE) procedure the variables load were altered to assess the weight loss in material. It is observed that with the increase in particle size and load, the weight loss increases when other variables are constant. Mn-steel shows decrease in weight loss at higher load due to property of dipole interaction and stacking fault energy (SFE). Decrease in weight loss at higher load results in transition in wear mechanism from scratch to groove formation as observed under field emission scanning electron microscope (FESEM).

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Thermal Effect of Er³⁺ Ions Embedded in Smart Nano-Composite Oxide Material Prepared by Sol-Gel Technique

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Battisha I. , Ayoub M. , Hashem A. , Ahmed E. , Amin A.

Acta Physica Polonica A

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2017

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tom 132

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nr 4

1277-1283

EN

The phosphosilicate for planar waveguides fabrication by using sol-gel, and particularly erbium-doped waveguide amplifiers, is reviewed. In particular, efforts to use sol-gel to improve molecular homogeneity in Er-doped phosphosilicate-based monolith and thin films will be discussed. A variety of material studies was carried out to investigate and optimize the sample preparation condition for such application. These include X-ray diffraction, the Fourier transform infrared and optical transmittance, absorption and refractive index calculation. The erbium nitrate precursors use is shown to alter the Er³⁺ ions doping in the prepared samples thermally treated in the final monolith glass form, in comparison to the use of thin film phosphosilicate sol-gel sample. Excess heat treatment is used to force prepared samples crystallization, moreover resulting photoluminescence analysis is used to detect the co-operative-up-conversion sample properties before and after heating.

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Synthesis and characterization of high-efficiency low-cost solar cell thin film

75%

Immanuel W. C. , Deborrah S. P. M. , Inbanathan S. S. R. , Sree D. N.

Materials Science Poland

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2019

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tom Vol. 37, No. 1

127--135

EN

Polycrystalline chalcogenide semiconductors play a vital role in solar cell applications due to their outstanding electrical and optical properties. Among the chalcogenide semi-conductors, CdZnS is one kind of such important material for applications in various modern solid state devices such as solar cells, light emitting diode, detector etc. Due to their applications in numerous electro-optic devices, group II-VI semiconductors have been studied extensively. In recent years, major attention has been given to the study of electrical and optical properties of CdZnS thin films. In this work, Cd1−xZnxS thin films were prepared by chemical bath deposition technique. Phase purity and surface morphology properties were analyzed using field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD) studies. Chemical composition was studied using energy dispersive spectrophotometry (EDS). Optical band gap property was investigated using UV-Spectroscopy. Electrical conductivity studies were performed by two probe method and thermoelectric power setup (TEP) to determine the type of the material. This work reports the effect of Zn on structural, electrical, microstructural and optical properties of these films.