Synthesis of Gd-Doped Ceria Films from (Ce, Gd)-EDTA Solutions via Atmospheric Sintering
Synthesis and characterization of La substituted M type Calcium Hexaferrite
First Principle Electronic, Magnetic and Thermodynamic Characterization of Gd2Cu2X (X= Cd, In, Mg)Isostructural Ternary Alloys
Soft Chemical Route Synthesized CdS/CuInGaSe2 Thin Films for Photovoltaic Application
Carbon Dioxide Gas Sensing Property of Nickel Substituted Zinc Ferrite
Surface Enhancement and Improved Mechanical Properties of SA-210 Gr. A1 Boiler Steel by Friction Stir Processing
An Investigation on Recent Trends in Metamaterial Types and its Applications
A Review on Plasma Ion Nitriding (PIN) Process
A Review on Friction and Wear Behaviors of Brake’s Friction Materials
A Review on use of Aluminium Alloys in Aircraft Components
Electro-Chemical Discharge Machining- A review and Case study
Comparison Of Composite Proton Conducting Polymer Gel Electrolytes Containing Weak Aromatic Acids
Enhancement in Electrical Properties of PEO Based Nano-Composite Gel Electrolytes
Electrical Properties of Nanocomposite Polymer Gels based on PMMA-DMA/DMC-LiCLO2 -SiO2
Effect of Donor Number of Plasticizers on Conductivity of Polymer Electrolytes Containing NH4F
PMMA Based Polymer Gel Electrolyte Containing LiCF3SO3
Gd-doped ceria (GDC) films were synthesized on Si substrates from (Ce, Gd)-EDTA solutions and atmospheric sintering. The (Ce, Gd)-EDTA solutions were coated onto silicon by a commercial spin coater and the coated samples were sintered in a furnace at 850 ℃ for 1 h. For the composition of Ce:Gd=0.8:0.2 in the EDTA complex with sintering at 850 ℃, only the crystalline phases of Ce0.8Gd0.2O1.9 were synthesised on the Si substrates. Microstructures of the Ce0.8Gd0.2O1.9 films had 78% 3D-relative densities as revealed by ellipsometry. Furthermore, the oxidation degree of the Ce ion was equal in the obtained Ce0.8Gd0.2O films at various experimental conditions as confirmed by XPS analysis.
La substituted M type Calcium hexaferrite with composition CaLaxFe12-xO19 (x=0.5, 1.0, 1.5, 2.0) were synthesized by sol gel auto combustion method. The prepared samples were characterized by XRD, SEM, EDAX, FTIR and VSM. X ray diffraction study shows that all the species have hexagonal crystal structure with lattice constants of a =5.87 - 5.91Å and c = 22.89 - 23.21 Å. There was increase in lattice volume with increasing La ion concentration. SEM images reveal that particles were hexagonal platelet-like shape, and the grain size increases with increase of La ion concentration. EDS measurements revealed the stoichiometric cationic ratios of the prepared samples. The absorption band between 520 cm-1 and 440cm-1 in FTIR confirm the formation of hexaferrite. The magnetic properties of the samples were studied by VSM. The change in magnetic parameters results make substituted hexaferrite material suitable for recording media.
Ternary Rare earth transition metal alloys with 2:2:1 stoichiometry viz. RE2Cu2X (RE= Rare earth, X= Cd, In, Mg) are used in the magnetic refrigeration technology due to their unique magnetic and physical properties. For more future aspect of technological applications, Gd2Cu2X (X= Cd, In, Mg) alloys have been preferred from RE2Cu2X series to study the spin polarized electronic, magnetic and thermodynamic properties using first principal theory. The spin polarized electronic behavior of Gd2Cu2X (X= Cd, In, Mg) shows that Gd-f orbital electrons play main role in the electronic conduction and magnetization. Magnetic calculations show high accuracy with available experimental/theoretical literature values on these materials. Thermodynamic calculations have been carried out in the wide temperature and pressure range for the first time.
Chalcopyrite heterojunction thin films of CdS/CuInGaSe2 were synthesized using soft chemical ion exchange route at room temperature over the Indium Tin Oxide (ITO) glass substrate for photovoltaic applications; these as-deposited thin films were characterized for structural, morphological, optical and electrical properties. The structural characteristics observed using X-ray diffraction pattern (XRD) represents (112), (212), (105) and (205) planes corresponding to chalcopyrite phase of tetragonal CuInGaSe2 material. Peak at 21.40o in XRD confirms CdS composition, while average crystallite size calculated to be 27nm. The XRD observations supported by Raman spectrum, which represents two shifts, at ~113cm-1 and 298cm-1 respectively corresponding to A1 and B2 mode of chalcopyrite CuInGaSe2 materials. Morphological studies using scanning electron microscopy (SEM) exhibits plate like petal distribution with smaller size particles attached over the substrate surface. The energy band gap calculated using extrapolating the absorbance spectra found to be ~1.47eV. This may corresponds to defect state and stiochiometry induced charge transfer the Hall Effect measurement revealed carrier charge concentration of 3x1023cm-3, charge mobility of 7.2 cm2/Vs. I-V studies shows ~1.12% conversion efficiency under light illumination condition of 100 mW/cm2.
The polycrystalline NiZn ferrite have been synthesized by co-precipitation method and characterized by X-ray powder diffraction and FTIR spectroscopy. The FTIR spectra obtained in the range from 400 cm-1to 4000 cm-1.Absorption bands observed at higher frequencies suggest the existence of significant modes of vibrations. The existence of absorption bands at frequency about 1627 cm-1, 2923 cm-1and 3437 cm-1are attributed to vibrational modes of triatomic water molecule. The absorption bands, observed at 414 cm-1and590 cm-1, confirm the formation of the spinel structure.Employing these materials, the sensing elements, were developed on cylindrical glass as substrate. Carbon dioxide (CO2) gas sensitive electrical properties of the compositions were investigated. The results are attributed to the chemisorption of oxygen species at specific operating temperature. Existence of nano crystallites favors surface phenomenon of adsorption. The materials show n-type conductivity at ambience and depict increase in the resistance due to presence of oxidizing gas. The electrical resistance of sensing elements (RCO2) was measured for variable concentration of CO2 gas from 0% to 15%. The RCO2 increases with increase in CO2. The sensitivities of the compositions under investigation are also estimated & result of investigation is discussed here.
Elevated temperature corrosion is an important material squalor mechanism knowledgeable in boilers in power plants energy generation sectors. Metallic materials such as low carbon steels have special properties such as easy fabrication and machinability, low cost, but a solemn disadvantage of these materials is that the deterioration in properties originating from the interface with the environment and has poor corrosion resistance. The main objective of the current investigation is to achieve strengthening of SA210 Grade A1 boiler steel through microstructural refinement by Friction Stir Processing (FSP) and analyze the effect of the same on high temperature corrosion behavior. The micro-structural, hardness, tensile and corrosion resistance of the unprocessed and FSPed materials was assessed. The characterization was done by XRD and SEM/EDS analyses with an intend to suggest mechanisms behind high temperature corrosion behavior of the FSPed samples.