In the current study, the peculiar nonlinear optical (NLO) properties of KAgCh (Ch = S, Se) and their structural, electronic, and thermodynamic properties are computed utilizing the FP-LAPW (full-potential linearized augmented plane wave)... more
In the current study, the peculiar nonlinear optical (NLO) properties of KAgCh (Ch = S, Se) and their structural, electronic, and thermodynamic properties are computed utilizing the FP-LAPW (full-potential linearized augmented plane wave) approach as embedded in Wein2K code. The Perdew–Burke–Ernzerh of generalized gradient approximation (PBE-GGA) was considered for the structural optimization. The computed bandgaps are found to be 2.57 and 2.39 eV for KAgS and KAgSe, respectively. Besides the structural and electronic properties, we also computed the refractive indices n(ω), surface energy loss function (SELF), and nonlinear optical susceptibilities. The estimated refractive indices, energy band gap, and their frequency dependence for the investigated KAgCh (Ch = S, Se) compounds, along with the NLO coefficients, are found to be in good agreement with the earlier reports. These current findings suggest that KAgCh (Ch = S, Se) can be recommended for nonlinear optical applications in ...
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This work focuses on study of the structural, electronic, thermodynamic and thermoelectric properties of RbNbCd and RbNbZn Half Heusler (HH), utilizing a full-potential linearized augmented plane wave (FP-LAPW) approach and the Boltzmann... more
This work focuses on study of the structural, electronic, thermodynamic and thermoelectric properties of RbNbCd and RbNbZn Half Heusler (HH), utilizing a full-potential linearized augmented plane wave (FP-LAPW) approach and the Boltzmann transport equation using a constant relaxation time approximation within the context of density functional theory (DFT) as embedded in the WIEN2k code. The structural analysis employed the generalized gradient approximation (GGA) and considered the Birch Murnaghan equation of state (EOS), which results in the stable phase for RbNbCd and RbNbZn. The positive phonon spectra indicate the dynamical stability of the studied RbNbCd and RbNbZn. The compounds under investigation that have no bandgap are metallic, as evidenced by their electronic properties. Their mechanical and thermal stability as well as their anisotropic and ductile character are confirmed by the various elastic and thermodynamic parameters. The lattice thermal conductivity has been calc...
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Due to the limited supply of fossil fuels in the modern era, humankind’s need for new energy sources is of utmost importance. Consequently, solar energy is essential to society. Solar energy is an endless and pure source of energy. Solar... more
Due to the limited supply of fossil fuels in the modern era, humankind’s need for new energy sources is of utmost importance. Consequently, solar energy is essential to society. Solar energy is an endless and pure source of energy. Solar energy research is being used to help solve the world’s energy dilemma, safeguard the environment, and promote significant sustainable economic growth. Humans have now constructed numerous solar photovoltaic power plants to produce electricity, and many people have installed solar panels on their homes’ roofs to do the same. The non-mathematical explanation of PV solar cell theory and its circuit architecture is covered in this chapter. It is written for a variety of groups, including engineers who need an introduction to the subject of photovoltaic cells, end users who require a deeper understanding of the theory to support their applications, students interested in PV science and technology, and others. The fundamentals of the individual electrici...
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In this work, the structural, elastic, electronic, thermodynamic, optical, and thermoelectric properties of cubic phase SnTiO3 employing first-principles calculation are examined. The calculations of all parameters via various potentials... more
In this work, the structural, elastic, electronic, thermodynamic, optical, and thermoelectric properties of cubic phase SnTiO3 employing first-principles calculation are examined. The calculations of all parameters via various potentials such as LDA, PBE-GGA, WC-GGA, PBEsol-GGA, mBJ-GGA, nmBJ-GGA, and HSE are performed. The computed band structure yields an indirect bandgap of 1.88 eV with the HSE approach. The optical parameters have been evaluated through absorption, dispersion, and loss function. For cubic phase SnTiO3, the maximum absorption coefficient α(ω) is 173 × 104 (cm)−1 at high energy region 9 eV. The thermoelectric properties of the SnTiO3 have been explored by the Seebeck coefficient, thermal conductivity, and power factor employing the BoltzTrap code with temperature and chemical potential. Furthermore, the thermodynamic quantities under high pressure (0–120 GPa) and temperature (0–1200 K) are also calculated.
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In this paper, the fabrication of PEDOT:PSS-doped graphene oxide (GO) as a hole transport conducting electrode has been discussed. GO has been synthesized by modified Hummer’s method. Formation of GO and structural changes in GO after... more
In this paper, the fabrication of PEDOT:PSS-doped graphene oxide (GO) as a hole transport conducting electrode has been discussed. GO has been synthesized by modified Hummer’s method. Formation of GO and structural changes in GO after PEDOT:PSS doping had been confirmed by Raman and XRD analyses. FESEM images depict the morphological changes in GO before and after doping. Bonds in the samples have been analyzed by FTIR. UV-Vis study shows that PEDOT:PSS-doped GO has good transparency in the visible region. Hall measurement indicates that the electrical conductivity in GO is due to the electron transport while the conductivity in PEDOT:PSS-doped GO is due to the hole transport. A new type of DSSC has been proposed with the fabricated hole transport PEDOT:PSS electrode without ITO. The working of the cell with the new hole transport electrode has been explained. Prepared electrodes have been used in the fabrication of DSSC, showing exciting initial results.
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In order to fulfil the growing need to replace fossil fuels, investigations exploring the production of biodiesel from agricultural biomass have gained attention. The purpose behind this study is to examine the efficiency of biodiesel... more
In order to fulfil the growing need to replace fossil fuels, investigations exploring the production of biodiesel from agricultural biomass have gained attention. The purpose behind this study is to examine the efficiency of biodiesel extracted from Madhuca longifolia and Jatropha curcas by means of pre-treatment followed by two step acid-base homogeneous catalyst method. The Madhuca and Jatropha biodiesels were blended with diesel at different percentages. Fourier Transform Infrared Spectroscopy (FTIR) showed a strong presence of fatty acid profile, and triglyceride ester linkage at 1744 cm− 1. UV–Vis spectra confirmed the presence of conjugated dienes in the extracted biodiesels. UV absorbance at 320 nm decreases linearly with blend percentage. 1HNMR and 13C NMR confirmed the presence of methyl ester moiety at 3.6 ppm and methoxy carbon at 51.2 ppm in biodiesel distinguishing it from diesel. Raman spectra exhibited C = O stretching at 1725 cm− 1 indicating conversion of Madhuca an...
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Lithium detection in materials is often crucial even with sophisticated compositional analysis techniques, like Energy Dispersive X-ray (EDX) spectroscopy and X-ray photoelectron spectroscopy (XPS). The present work focuses on the... more
Lithium detection in materials is often crucial even with sophisticated compositional analysis techniques, like Energy Dispersive X-ray (EDX) spectroscopy and X-ray photoelectron spectroscopy (XPS). The present work focuses on the three-dimensional compositional mapping of Li in Li-doped ZnO films using atom probe tomography (APT). A syringe pump spray pyrolysis (SSP) technique was prosperously used to synthesize undoped and Li doped zinc oxide (ZnO) thin films with Li concentration range from 0 to 8 at.%. onto glass substrates. The chemical reagents used for this experiment are Zinc acetate (Zn(acac)2) and lithium acetate (Li (acac)2) under atmospheric conditions. Spectroscopic analyses of the films using Raman and Fourier transform infra-red (FTIR) spectroscopic techniques were done to confirm phase formation. Diffuse but strong absorption peaks within 400 – 600 cm-1 in FTIR spectra confirm compound formation while the existence of E2High and E1(LO) vibration modes in Raman spectr...
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Doping of CdTe quantum dots (QDs) has been found to be difficult task and this QD-system was considered as ‘undopable’ for long due to the ‘self-purification’ phenomenon that dominates the growth-process. Here we present a facile aqueous... more
Doping of CdTe quantum dots (QDs) has been found to be difficult task and this QD-system was considered as ‘undopable’ for long due to the ‘self-purification’ phenomenon that dominates the growth-process. Here we present a facile aqueous approach to synthesize Mn-doped CdTe quantum dots (d-dots) by controlling the degree of supersaturation of the initial synthetic mixture. By increasing the degree of Supersaturation by four times, Mn-CdTe d-dots were obtained which show remarkable improvement in photoluminescence (PL) spectral profile and PL efficiency. The sizes of the Mn-CdTe d-dots were tuned from 2.5 nm to 3.5 nm and the size distribution was also narrowed down significantly.
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In this work, the effects of Ba(Fe0.5Nb0.5)O3 (BFN) addition on the structure and dielectric behaviour of Ba0.06(Na0.5Bi0.5)0.94TiO3 (BNBT) ceramics have been reported. The lead-free (1-x)BNBT-xBFN (where 0 ? x ? 1.0) solid-solutions were... more
In this work, the effects of Ba(Fe0.5Nb0.5)O3 (BFN) addition on the structure and dielectric behaviour of Ba0.06(Na0.5Bi0.5)0.94TiO3 (BNBT) ceramics have been reported. The lead-free (1-x)BNBT-xBFN (where 0 ? x ? 1.0) solid-solutions were synthesized by traditional ceramics fabrication technique and sintered at temperatures up to 1325?C. The X-ray diffraction peaks of the compounds of the entire series were indexed. It is found that the crystal structure of the obtained solid solutions changed from rhombohedral (R3c) to cubic (Pm3m) with an increase in BFN content. The Fourier transformed infrared and Raman spectra also confirmed the formation of solid-solutions. SEMstudies were carried out to evaluate the purity and microstructure of the fabricated ceramics. The dependence of phase transition broadening, phase transition temperature and dielectric parameters with compositional changes were also studied.
This paper reveals the impact of oxygen in the phase growth of titanium oxide thin films. Films were developed using dc magnetron sputtering with Ti metal target at very low oxygen partial pressures (0 - 0.04) for 30 min. X-ray... more
This paper reveals the impact of oxygen in the phase growth of titanium oxide thin films. Films were developed using dc magnetron sputtering with Ti metal target at very low oxygen partial pressures (0 - 0.04) for 30 min. X-ray reflectivity (XRR) of the films was done to ascertain the variations in the structural properties of the films. Film roughness continually increases even for slight variations in oxygen partial pressure while the film density stabilizes within 3.6 - 3.8 g/cm3 with increasing oxygen content. L2,3 and O K-edge X-ray absorption near-edge structure (XANES) spectroscopy was done to identify the phase structures and oxidation states of the films. As-deposited films are all amorphous in nature, with no major change in their properties apart from increased thickness (280 -910 A). After post heating the films at 400 °C for 5h in vacuum (10-5 torr) various crystalline phases evolve. A slight increase in oxygen partial pressure leads to a gradual transformation in the evolved phase of TiO2 films. Ti2O3 phase with Ti[5] coordination environment and Ti3+ oxidation state was detected with O2 partial pressure of 0.015 whereas a metastable anatase and stable rutile phase with Ti[6] coordination environment and Ti4+ oxidation state was observed with 0.02 and 0.04 O2 partial pressures, respectively.
Environmental impacts of fossil fuels and their limited supply are driving the development and use of bio-diesel. Globally, bio-diesel is gaining importance because of its environmental advantages. Jatropha curcas has been widely... more
Environmental impacts of fossil fuels and their limited supply are driving the development and use of bio-diesel. Globally, bio-diesel is gaining importance because of its environmental advantages. Jatropha curcas has been widely considered as a potential feedstock for the production of bio-diesel in several tropical countries. This study employs a method of data collection that is a face-to-face interview, along with a questionnaire. The questionnaire is designed, taking into consideration, different aspects of sustainable development. The survey is conducted in Kolkata, based on bio-diesel producing companies. Statistical analysis using SPSS version 17 is used for analysing the data collected from different bio-diesel producing companies from respondents of sample size 100 based on the questionnaire. Analysis of primary data collected is evaluated by chi-square and correlation tests. The results indicate that the relationship of design, maintenance, process capability, facility management, transportation, quality, technology, material, and human resource with sustainable development, is statistically significant and positively correlated. The major barriers that industries are facing relate to inadequate quality management, missing engine approvals and high raw material cost. Removal of tax hurdles and supportive legislative measures are the most efficient measures for overcoming these barriers.
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Doping of CdTe quantum dots (QDs) has been found to be difficult task and this QD-system was considered as ‘undopable’ for long due to the ‘self-purification’ phenomenon that dominates the growth-process. Here we present a facile aqueous... more
Doping of CdTe quantum dots (QDs) has been found to be difficult task and this QD-system was considered as ‘undopable’ for long due to the ‘self-purification’ phenomenon that dominates the growth-process. Here we present a facile aqueous approach to synthesize Mn-doped CdTe quantum dots (d-dots) by controlling the degree of supersaturation of the initial synthetic mixture. By increasing the degree of Supersaturation by four times, Mn-CdTe d-dots were obtained which show remarkable improvement in photoluminescence (PL) spectral profile and PL efficiency. The sizes of the Mn-CdTe d-dots were tuned from 2.5 nm to 3.5 nm and the size distribution was also narrowed down significantly.
Bio-diesel has been identified as an alternative fuel, mainly because of its biodegradable, renewable and non-toxic characteristics. Jatropha curcas is one of the non-edible vegetable-based potential sources of bio-diesel. The purpose of... more
Bio-diesel has been identified as an alternative fuel, mainly because of its biodegradable, renewable and non-toxic characteristics. Jatropha curcas is one of the non-edible vegetable-based potential sources of bio-diesel. The purpose of this study is to investigate the efficiency of bio-diesel extracted from crude Jatropha oil using double filtration method. The bio-diesel was blended with mineral diesel at different percentages, before being applied as a fuel source for an engine performance test. Besides, the Jatropha bio-diesel was also characterized using Fourier transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV–Vis) spectroscopy. FTIR determines its diesel characteristics and fatty acid profile. UV–Vis absorption spectra determine the various blending concentrations.
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ABSTRACT A technique to deposit Nb-doped films of TiO2 by radio-frequency magnetron sputtering was investigated. Nb wires are put onto the sputter track of a metallic titanium target and the oxidation state of the target is controlled by... more
ABSTRACT A technique to deposit Nb-doped films of TiO2 by radio-frequency magnetron sputtering was investigated. Nb wires are put onto the sputter track of a metallic titanium target and the oxidation state of the target is controlled by the intensity of a Ti line from the plasma emission. The sputtered films are analyzed with X-ray diffraction, RBS (Rutherford back scattering), energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and SEM (scanning electron microscopy). After post-heating at 400 °C, all films exhibit the anatase structure. The films are polycrystalline with a Nb/[Nb + Ti] content from 2 to 17 at.%. RBS and SEM indicate that the films consist of two sub-layers with the surface layer containing more Nb and exhibiting a clearer columnar structure. There is an optimum oxidation state of the target in the transition region between metallic and oxidic modes where the lowest resistivity of 7 × 10− 4 Ωcm is achieved. Nb is incorporated as Nb5 + into the anatase lattice, but in suboptimal films, Ti vacancies (acceptors) may compensate the donor effect of Nb. The oxygen content in the films is higher than for stoichiometric TiO2. O interstitials may increase the mass density of the films. The lattice parameter a and the unit cell volume increase with the Nb content in a similar manner as observed for single crystals of TiO2:Nb.
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A technique to deposit Nb-doped films of TiO2 by radio-frequency magnetron sputtering was investigated. Nb wires are put onto the sputter track of a metallic titanium target and the oxidation state of the target is controlled by the... more
A technique to deposit Nb-doped films of TiO2 by radio-frequency magnetron sputtering was investigated. Nb wires are put onto the sputter track of a metallic titanium target and the oxidation state of the target is controlled by the intensity of a Ti line from the plasma emission. The sputtered films are analyzed with X-ray diffraction, RBS (Rutherford back scattering), energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and SEM (scanning electron microscopy). After post-heating at 400 °C, all films exhibit the anatase structure. The films are polycrystalline with a Nb/[Nb + Ti] content from 2 to 17 at.%. RBS and SEM indicate that the films consist of two sub-layers with the surface layer containing more Nb and exhibiting a clearer columnar structure. There is an optimum oxidation state of the target in the transition region between metallic and oxidic modes where the lowest resistivity of 7 × 10− 4 Ωcm is achieved. Nb is incorporated as Nb5 + into the anatase lat...
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Thin solid films of copper, aluminum and nichrome have been deposited on glass substrates with thickness ranging from 20 nm to 200 nm, using the anodic vacuum arc deposition technique. Electrical resistivity and average grain size of... more
Thin solid films of copper, aluminum and nichrome have been deposited on glass substrates with thickness ranging from 20 nm to 200 nm, using the anodic vacuum arc deposition technique. Electrical resistivity and average grain size of deposited thin films have been ...
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ABSTRACT Thin films of TiO2 were deposited by reactive sputtering of a Ti target on unheated substrates and post-heated at 300 °C and 500 °C. They exhibit a granular structure. Direct current-sputtered films are amorphous as-deposited and... more
ABSTRACT Thin films of TiO2 were deposited by reactive sputtering of a Ti target on unheated substrates and post-heated at 300 °C and 500 °C. They exhibit a granular structure. Direct current-sputtered films are amorphous as-deposited and crystallize (to pure anatase) only at 500 °C. Radio-frequency (rf)-sputtered films are already crystalline (pure anatase) asdeposited on unheated substrates. Above a thickness of 100 nm, the crystallite size, as deduced from the half-width of X-ray diffraction (XRD) peaks, is constant at 35 nm and decreases to zero when the thickness decreases to 25 nm. Below a thickness of 25 nm, the films are X-ray amorphous. Height and half-width of the XRD peaks of rf-sputtered films do not change upon post-heating at 300 or 500 °C. A larger lattice parameter ratio c/a is observed with respect to the bulk value that decreases with increasing film thickness and is about 1% larger for a film thickness larger than 100 nm.
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ABSTRACT Thin films of TiO2 were deposited by reactive sputtering of a Ti target on unheated substrates and post-heated at 300 °C and 500 °C. They exhibit a granular structure. Direct current-sputtered films are amorphous as-deposited and... more
ABSTRACT Thin films of TiO2 were deposited by reactive sputtering of a Ti target on unheated substrates and post-heated at 300 °C and 500 °C. They exhibit a granular structure. Direct current-sputtered films are amorphous as-deposited and crystallize (to pure anatase) only at 500 °C. Radio-frequency (rf)-sputtered films are already crystalline (pure anatase) asdeposited on unheated substrates. Above a thickness of 100 nm, the crystallite size, as deduced from the half-width of X-ray diffraction (XRD) peaks, is constant at 35 nm and decreases to zero when the thickness decreases to 25 nm. Below a thickness of 25 nm, the films are X-ray amorphous. Height and half-width of the XRD peaks of rf-sputtered films do not change upon post-heating at 300 or 500 °C. A larger lattice parameter ratio c/a is observed with respect to the bulk value that decreases with increasing film thickness and is about 1% larger for a film thickness larger than 100 nm.
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Research Interests: Engineering, Applied Physics, Scanning Electron Microscopy, Crystal structure, Standard Deviation, and 14 moreMathematical Sciences, Applied, Thin Film, Physical sciences, Electrical Resistance, Iron, Surface Morphology, X ray diffraction, Effective mass, Copper Alloy, Nanostructured Material, Electron Beam, Nickel Alloy, and Fermi Surface
ABSTRACT Thin sputtered films of TiO2 of various thicknesses are characterized by their strain along the crystalline c−axis. The Raman B1g 519 cm−1 mode experiences a strong blue shift, whereas the Eg 144 cm−1 peak is at the standard... more
ABSTRACT Thin sputtered films of TiO2 of various thicknesses are characterized by their strain along the crystalline c−axis. The Raman B1g 519 cm−1 mode experiences a strong blue shift, whereas the Eg 144 cm−1 peak is at the standard position for all samples. The Raman intensity of the prominent Eg 144 cm−1 peak increases upon annealing at 300 °C, contrary to the integral intensity of XRD reflexes which remains constant. The half−width of the Eg 144 cm−1 peak is determined by the crystallite size. Dielectric modelling of the optical transmittance spectra indicates, for all samples, the existence of defect states leading to transitions 0.3−0.5 eV lower than the band gap. The growth process becomes stationary for a film thickness above 100 nm for rf−sputtered and above 200 nm for dc−sputtered films.
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Inductively coupled plasma optical emission spectrometry (ICP-OES) was applied for the analysis of major and minor elements of thermoelectric alloys (Constantan, Chromel and Alumel) and their thin films deposited using anodic vacuum arc... more
Inductively coupled plasma optical emission spectrometry (ICP-OES) was applied for the analysis of major and minor elements of thermoelectric alloys (Constantan, Chromel and Alumel) and their thin films deposited using anodic vacuum arc (AVA) plasma deposition ...
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SK Mukherjee,a) MK Sinha, B.. Pathak, SK Rout, and PK Barhai Department of Applied Physics, Birla Institute of Technology Mesra, Ranchi, Jharkhand 835215, India (Received 21 December 2009; published online 15 January 2010) ... This... more
SK Mukherjee,a) MK Sinha, B.. Pathak, SK Rout, and PK Barhai Department of Applied Physics, Birla Institute of Technology Mesra, Ranchi, Jharkhand 835215, India (Received 21 December 2009; published online 15 January 2010) ... This article was originally ...
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Inductively coupled plasma optical emission spectrometry (ICP-OES) was applied for the analysis of major and minor elements of thermoelectric alloys (Constantan, Chromel and Alumel) and their thin films deposited using anodic vacuum arc... more
Inductively coupled plasma optical emission spectrometry (ICP-OES) was applied for the analysis of major and minor elements of thermoelectric alloys (Constantan, Chromel and Alumel) and their thin films deposited using anodic vacuum arc (AVA) plasma deposition ...
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Thin solid films of copper, aluminum and nichrome have been deposited on glass substrates with thickness ranging from 20 nm to 200 nm, using the anodic vacuum arc deposition technique. Electrical resistivity and average grain size of... more
Thin solid films of copper, aluminum and nichrome have been deposited on glass substrates with thickness ranging from 20 nm to 200 nm, using the anodic vacuum arc deposition technique. Electrical resistivity and average grain size of deposited thin films have been ...
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Abstract This paper investigates the corrosion behaviour of type K thermoelements and their thin films, and compares the performance of chromel-alumel thin film thermocouple with its wire counterpart before and after exposure to 5% NaCl... more
Abstract This paper investigates the corrosion behaviour of type K thermoelements and their thin films, and compares the performance of chromel-alumel thin film thermocouple with its wire counterpart before and after exposure to 5% NaCl medium. Potentiodynamic ...
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Research Interests: Engineering, Applied Physics, Scanning Electron Microscopy, Crystal structure, Standard Deviation, and 14 moreMathematical Sciences, Applied, Thin Film, Physical sciences, Electrical Resistance, Iron, Surface Morphology, X ray diffraction, Effective mass, Copper Alloy, Nanostructured Material, Electron Beam, Nickel Alloy, and Fermi Surface
... Fig. 1. Schematic diagram of anodic vacuum arc deposition unit. View Within Article. After contacting the electrodes shortly one or few bright cathode spots appear on the cathode surface. These cathode spots move slowly and show... more
... Fig. 1. Schematic diagram of anodic vacuum arc deposition unit. View Within Article. After contacting the electrodes shortly one or few bright cathode spots appear on the cathode surface. These cathode spots move slowly and show severe erosion of the cathode surface. ...