Research Papers/Topics in Material Science

Formation of Metastable Calcite-type Barium Carbonate During Low-temperature Decomposition of (Ba,Ti)- Precursor Complexes

Solid State Sciences 9 (2007) 303, doi:10.1016/j.solidstatesciences.2007.02.003, Abstract::(Ba,Ti)-precursor complexes, important for the production of advanced BaTiO3 perovskitetype materials, undergo structural transformations and complex reactions during their thermal decomposition. Based on XRD phase analysis, combined with Rietveld refinement of crystal structure data, and on IR analysis, the intermediate formation of calcite-type BaCO3 is evidenced, which can be explained by the stabili...

Barium Titanate via Thermal Decomposition of Ba,Tiprecursor Complexes: The Nature of the Intermediate Phases

Solid State Sciences 9 (2007) 21, doi:10.1016/j.solidstatesciences.2006.09.004,Abstract::The thermal decomposition of Ba,Ti-precursor complexes, containing organic ligands and suitable for the single-source preparation of nanocrystalline BaTiO3, leads firstly to the segregation of specific Ba-rich and Ti-rich phases. Quantitative electron energy lossspectroscopy and powder X-ray diffraction data indicated that the (i) Ba-rich phase is a BaOstabilised variant of the calcite-type high temperatu...

Semiconducting Properties of Ge-BaSnO3

Journal of Alloys and Compounds 506 (2010) 678–682, doi:10.1016/j.jallcom.2010.07.041,Abstract::The electrical and optical properties of Ge-doped BaSnO3 ceramics sintered at various temperatures have been investigated to determine their semiconductor behavior. The electrical conductivity of Ge-doped BaSnO3 samples increases with increase in temperature, confirming that the samples exhibit a semiconductor behavior. A maximum conductivity value of 6.31 × 10−9 S/cm was observed for the samp...

Thermoanalytical, Optical, and Magnetic Investigations on Nanocrystalline Li0.5Fe2.5O4 and Resulting Ceramics Prepared by a Starch-based Soft-chemistry Synthesis

Journal of Solid State Chemistry 287 (2020) 12138. DOI: 10.1016/j.jssc.2020.121380 Abstract: Nanocrystalline Li0.5Fe2.5O4 was prepared by a starch-based soft-chemistry synthesis. Calcining of the (LiFe)-gel between 350 and 1000 °C results in Li0.5Fe2.5O4 powders with crystallite sizes from 13 to 141 nm and specific surface areas between 35 and 7.1 m2 g-1. XRD investigations reveal the formation of ordered Li0.5Fe2.5O4. Sintering between 1050 and 1250 °C leads to ceramics with relative ...

BaGeO3 as Sintering Additive for BaTiO3-MgFe2O4 Composite Ceramics

RSC Adv., 2015, 5, 71491, DOI: 10.1039/c5ra12312g, Abstract::BaTiO3-MgFe2O4 composites (30 wt.% MgFe2O4) with a small addition of BaGeO3 as a sintering additive were synthesized by a one-pot Pechini-like sol-gel process. Nano-crystalline composite powders with a crystallite size of about 10 nm were obtained after reaction at 700 °C for 1 h. Magnetic investigations suggest that the nano-powder is in its superparamagnetic state at room temperature. The addition of BaGeO3 leads to an improved s...

Characterization Of SnxSey /SnO2: Co p-n Junction Deposited By Spray Pyrolysis For Photovoltaic Application

ABSTRACT Research on utilization of solar energy has been stimulated by Energy crisis in everyday usage of energy. Photovoltaic hold great hopes towards solving energy crisis since they are environment friendly, sunlight is free, abundant and not likely to be exhausted in the near future. In this study SnxSey and SnO2: Co thin films were prepared by spray pyrolysis deposition technique at deposition temperatures of 400 K and 500 K respectively. SnxSey precursor was prepared using 0.05M ...

Novel Comparative Study And Characterization Of Plant Dyes In Tio2 Matrix For Dye Sensitized Solar Cells Applications

ABSTRACTA good energy mix is desirable for sustainability of the energy needs of many countries. Currently, electricity, including that sourced from photovoltaic cells is widely used for not only homesteads but also for industries. The desire to develop a cost-effective source of energy has motivated the development of dye sensitized solar cells. This technology has motivated a lot of research owing to its improved efficiency. This work has utilized plant extracts usi...

Optical And Electrical Characterization Of Sns – Sno2: Sb P-N Junction For Solar Cell Applications

ABSTRACTFor sustainability of future civilization, development of alternative clean energy technologies to replace fossil fuels has become one of the most crucial and challenging problems of the last few decades. Thin film solar cells is one of the major photovoltaic technologies that is promising for renewable energy conversion. The PV cells currently in use today are silicon based, though other cells have been fabricated using other semiconductors. Recent research is focused on fabrication ...

Models Of Tensile Behaviour Of Meta-Stable Fe-Mn-Mo Alloys

ABSTRACT  A semi-mechanistic model for predicting the flow behaviour of Fe-Mn-Mo steels displaying transformation-induced plasticity is developed in this paper. The model, based on the law of mixtures, takes into account the work-hardening of the individual principal phases (namely, lath-martensite and austenite/epsilon martensite). The composite strength of such a steel may be given by a modified law of mixtures which incorporates a dislocation density effect. To test the validi...

Deformation Characteristics And Work-Hardening Behaviour Of Some High Strength Manganese Steels.

AbstractA Study Has Been Made On A New Type Of WearResistant/High Strength Iron-Manganse-Molybdenum Steel. ThisStudy Includes The Influence Of Composition And Heat TreatmentOn The Mechanical Properties. The Exceptional Work-HardeningRate Is Due To Strain-Induced Formation Of Lath MartensiteWhich Itself Also Takes Part In The Work-Hardening Process.The Influence Of Higher Molybdenum Contents Was Evident InPreventing Brittleness Of The Solution Treated Steels. AnOptimum Composition Range...

Deformation Characteristics And Work-Hardening Behaviour Of Some High Strength Manganese Steels

ABSTRACTA study has been made on a new type of wearresistant/high strength iron-manganse-molybdenum steel. Thisstudy includes the influence of composition and heat treatmenton the mechanical properties. The exceptional work-hardeningrate is due to strain-induced formation of lath martensitewhich itself also takes part in the work-hardening process.The influence of higher molybdenum contents was evident inpreventing brittleness of the solution treated steels. Anoptimum composition range...

Development of Mathematical Equation for Fraction of Solid in AlSi7Mg Alloy Solidification Simulation

ABSTRACT Thermodynamic data is made use of in calculating fraction of metal solidified in solidification simulation. However, thermodynamic data for many industrial alloys in their solidification ranges are not available for most practicing engineers. It is thus desirable to develop reliable equations that can be used in calculating fraction of metal solidified for solidification simulation. This work has developed an equation to calculate fraction of metal solidified for AlSi7Mg al...

Effect Of Concentration Of Reactants And Deposition Temperature On The Optical Properties Of Iron-Doped Cadmium Stannate Thin Films Deposited On Glass Substrates By Spray Pyrolysis

ABSTRACTThin films (TFs) have numerous applications in the modern technological world, ranging from energy production in TF solar cells/ photovoltaic (PV) cells to liquid crystal displays (LCDs) in television screens and in smartphone touch screens as transparent conducting oxides (TCOs). The most commonly used TCO material is indium tin oxide (ITO). However, ITO has two main drawbacks. Firstly, indium is expensive and secondly, it is rare. These drawbacks call for relatively cheaper compound...

Quantum Entanglement Properties Of Polarization States Of A Semi-Classical Optical Parametric Oscillator

ABSTRACTEntanglement is a fundamental feature of quantum mechanics which originated from the 1935 paper of Einstein, Podolsky and Rosen (EPR) and has been demonstrated in many quantum systems for development of quantum technology. Entanglement of photons occurs through polarization states generated in nonlinear parametric processes. The Optical parametric oscillator (OPO) constitutes a nonlinear process in which a pair of entangled photons (signal and idler) is generated when a light mode fro...


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