Archives-September 2012

High quality bulk single crystal of L-arginine phosphate (LAP) was grown by slow evaporation which is based on temperature reduction method. L-arginine phosphate (LAP) seed crystals were grown at pH value of 5.8 at 30⁰ C by slow evaporation technique around 12 days and the bulk crystal was grown by Mason-jar method for 20 days. The grown crystals were subjected to optical and morphological studies. The unit cell parameters were calculated by X- ray diffraction. The UV-Vis spectrum shows the transmitting ability of the crystals in the entire visible region and the transmittance percentage is increased for the LAP crystals. The presence of the functional groups was identified by FT-IR spectrum. Hence L-arginine crystals are found to be more beneficial from an application point of view as compared to KDP crystals. From Micro hardness test the mechanical strength of the crystal has been observed.

Thin film patterned CdS is considered to be as the most promising semiconducting materials among various structures because of its tunable physical properties which leads the material to the recent applications such as solar cells, sensors, hydrogen storage devices, modulators etc. Moreover, in order to form CdS thin films chemical bath deposition techniques is one of the easiest method among various techniques. It is due to the fact that it has many advantages such as simplicity, no requirements for sophisticated instruments, minimum wastage, economical way of large area deposition, no need of handling poisonous gases and possibility of room temperature depositions. With these advantages in mind an attempt has been made to deposit device quality CdS thin films at various temperatures by CBD technique. The thicknesses of the deposited films have been determined by gravimetry. The structural characterization is carried out by X-ray diffraction. The study confirms the polycrystalline nature of films with hexagonal structure. The structural parameters such as grain size, dislocation density, strain and lattice parameters have been evaluated. The composition of various constituents in CdS films have been determined by energy dispersive X-ray analysis. The optical properties like optical transmittance, band gap and refractive index has been studied in detail for the CdS films of various thicknesses.

Strontium titanate has been synthesized successfully by using solution growth and Chemical solution deposition method in powder and thin film form.The chemical composition of the resulted samples were analyzed by EDX and the morphology was observed by Scanning electron microscope. The structure and phase composition were characterized by X-ray diffraction.

PbS_xO_1-x (x = 0.0, 0.2, 0.4, 0.5, 0.6, 0.8 and 1.0) nanocomposites were prepared by the microwave assisted solvothermal method using a domestic microwave oven for the first time. The yield percentage and the preparation time were noted. The samples were annealed at 200 ^oC for 1 hr to improve the ordering.  Grain sizes and lattice parameters were determined by carrying out X-ray powder diffraction measurements. AC and DC electrical measurements were carried out on palletised samples at various temperatures ranging from 40-150 ^oC.  Results of the present study reveal that the space charge contribution plays a significant role in the charge transport process and polarizability in all the seven nanocrystals studied. The electrical parameters increase with increasing temperature. Results of the present study reveal that the space charge contribution plays a significant role in the charge transport process and polarizability in all the seven nanocrystals studied.

An organic nonlinear optical crystal of Cesium Sulfamate crystal has been synthesised and grown by the slow evaporation solution growth method. Single crystals of optical quality were obtained by slow evaporation technique. The grown crystals were characterised by powder XRD, UV-visible spectroscopy, DTA analysis and SHG measurement test. The SHG efficiency of crystal is greater than urea and transmittance cut off wavelength is 424nm. Hyperpolarizability analysis of Cesium Sulfamate were performed with the help of Density Functional Theory (DFT) calculations using Gaussian 03 software.

We are very happy to announce that from 19th September 2012, Dr. Seema Verma has joined the team of Elixir Editorial Advisory Board. He will carry a special responsibility for dealing with manuscripts based on Electronics. Dr. Seema Verma is currently working with Associate Professor, Department of Electronics, Banasthali University, Rajasthan-304022-India. The appointment of Dr. Seema Verma as member Editorial Advisory Board strengthens the links and will make it easier for prospective authors to establish contact with the journal. Please send any expressions of interest to chiefeditor@elixirjournal.org. Sincerely Editor-in-Chief

We are very happy to announce that from 7th September 2012, Dr.P.Sivaprakash has joined the team of Elixir Editorial Advisory Board. He will carry a special responsibility for dealing with manuscripts based Mechanical Engineering. Dr.P.Sivaprakash is currently associated with Associate Professor, Department of Mechanical Engineering, Karpagam Institute of Technology, Coimbatore - 641105, Tamilnadu, India. The appointment of Dr.P.Sivaprakash as member Editorial Advisory Board strengthens the links and will make it easier for prospective authors to establish contact with the journal. Please send any expressions of interest to chiefeditor@elixirjournal.org. Sincerely Editor-in-Chief

Table of contents for the month of September 2012

Metal oxides play a very important role in many areas of chemistry, physics and materials science.  The metal elements are able to form a large diversity of oxide compounds.  These can adopt a vast number of structural geometries with an electronic structure that can exhibit metallic, semiconductor or insulator character. In technological applications, oxides are used in the fabrication of microelectronic circuits, sensors, Piezo-electric devices, fuel cells, coatings for the passivation of surfaces against corrosion, and as catalysts. In the emerging field of nanotechnology, a goal is to make nanostructures or nanoarrays with special properties with respect to those of bulk or single particle species.  Oxide nanoparticles can exhibit unique physical and chemical properties due to their limited size and a high density of corner or edge surface sites. Amomg the metal oxides,  Magnesium oxide (MgO) is widely used in the chemical industry as a scrubber for air pollutant gases (CO₂, NO_X, SO_X) and as a catalyst support.  It exhibits a rock salt structure like oxides of other alkaline earth metals.  The non-polar (100) face is by far the most stable surface,  and particles of MgO usually display a cubic shape. For example, when Mg metal is burned in air or oxygen, the MgO smoke particles that are formed are almost perfect cubes having (100) faces.