Crystal Research

The FTIR spectrum shows that the carbonyl group of L-Leucine, L-Glutamic acid and L-Tyrosine interact with 2-aminopydine through N—H?O hydrogen bonding. 2-aminopyridine protonated and L-amino acids deprotonated during the reaction, resulting in the formation of 2-aminopyridiniumleucinate, bis2-aminopyridinium glutamate and 2-aminopyridiniumtyrosinate co-crystals. The UV-Vis spectrum shows that the molecules are closely packed and undergoes n??^* transition in all these three co-crystal and the cut off wavelength value indicate that bis2-aminopyridinium glutamate and 2-aminopyridiniumtyrosinate co-crystals have Non-linear optical property compared to 2-aminopyridiniumleucinate crystals. The cell parameter calculated from powder XRD pattern.

This work has been done with using of polyproplyen (pp) as a matrix, which reinforced with fibers glass (glass fiber short , glass fiber woving roving , and glass fiber short +, glass fiber woving roving ). The research also studies the Mechanical properties (Creep- Impact ) of the Samples with the same volume fraction (30%) and comparing the results.These tests are carried out on samples under the influence of normal conditions room temperature (23+3oC) and after immersion of all samples in the chemical solutions (KOH-HCL- NaCO3). The normality for all these chemical solutions is 0.5. The results showed when time immersion increase these properties are decreased, which indicates the negative effects of these chemical solutions on the mechanical properties. Tests showed that the results of the values of each of the creep resistance and impact increases after immersion in chemical solutions, and that the solution KOH is more influential. Results show that samples of blend reinforced [PP + f.g (w.r+r)] possess better creep resistance, and sample of [PP+f.g (w-r)] possess better impact resistance at all conditions tests (room temperature and after immersion in chemical solutions).

We describe various misconceptions and misinterpretations concerning presentation of the hysteresis loop for ferromagnets occurring in undergraduate and college textbooks. These problems originate from our teaching a Theoretical solid state / condensed matter physics (TSSP/CMP) course. A closer look at the definition of “coercivity” reveals two distinct notions referred to as the hysteresis loop: B vs. H or M vs. H, which can be easily confused and, in fact, are confused in several textbooks. The properties of the M vs. H type hysteresis loop are often ascribed to the B vs. H type loops, giving rise to various misconceptions. An extensive survey of textbooks at first in the TSSP/CMP area and later extended into the areas of general physics, materials science and magnetism / electromagnetism has been carried out. Relevant encyclopedias and physics dictionaries have also been consulted. The survey has revealed various other substantial misconceptions and/or misinterpretations than those originally identified in the TSSP/CMP area. The results are presented here to help in clarifying the misconceptions and misinterpretations in question. The physics education aspects arising from the textbook survey are also discussed. Additionally, analysis of the CMP examination results concerning questions pertinent to the hysteresis loop is provided.

Single crystals of pure Zinc Tris-thiourea Chloride (ZTC) and L-alanine- doped ZTC were grown from aqueous solutions by slow evaporation technique. The grown crystals have been subjected to single crystal x-ray diffraction to determine the unit cell dimensions. The Fourier Transform Infrared (FT-IR) spectra has been recorded in the range 400-4500 cm-1. Morphological alterations have been observed when L-alanine was doped into ZTC crystals. UV-Visible spectrum shows that the grown crystals have wide optical transparency in the entire visible region. The grown crystals were also subjected to other characterizations such as micro hardness, thermal and NLO studies.

Semi-organic nonlinear optical crystals of Tribismuthnonakisthioureanonachloride dihydrate has been grown by single diffusion gel growth technique. Powder XRD study reveals that the grown crystal belongs to triclinic system. Decomposition mechanism and melting point of the sample were deliberated in TGA/DSC analysis. Band gap energy value was calculated from photoluminescence spectrum. Dielectric constant of the crystal is premeditated as a function of frequency.

Benzilic Acid is an organic material with interesting nonlinear optical properties, in particular Second Harmonic Generation (SHG).It was synthesized and single crystals were grown by slow evaporation method. Unit cell parameters were evaluated by single crystal and powder X-ray diffraction techniques. The formation of the material was confirmed qualitatively by FT-IR analysis and its optical transmittance was studied. The Thermal and mechanical properties were analised. The SHG efficiency was also measured.

In order to get good-quality crystals, method of slow evaporation was adopted to grow pure and L-Arginine doped Zinc (tris) Thiourea sulphate (ZTS) single crystals. The grown crystals are semiorganic non linear in nature whose lattice parameter values were found out using single x-ray diffraction analysis. The different functional bond frequencies associated with the crystals, decomposition temperature, and weight loss were found out from Fourier transform infra-red (FTIR) spectroscopic analysis, differential thermal analysis (DTA), and thermo-gravimetric analysis (TGA) respectively. The optical behavior, mechanical stability and etching nature were also analysed. The SHG efficiency of the grown crystals was measured through NLO studies.

Single crystals of pure and Glycine-doped Zinc Thiourea Chloride (ZTC) were grown by slow evaporation technique. 1 molar percent of Glycine was added in saturated ZTC solution. The chemical composition of the crystals were determined by Fourier transform infrared (FTIR) analysis. The unit cell parameters and crystal structure were determined by single crystal X-ray diffraction. The UV-visible absorption spectra of pure and Glycine-doped ZTC showed excellent transmittance from 300 nm to 1100 nm. The thermal stability of the grown crystals was studied by thermo-gravimetric analysis (TGA). The second-harmonic generation efficiencies were studied by Kurtz and Perry powder SHG test and observed an enhancement in the SHG efficiency of Glycine-doped ZTC. Micro hardness study was also carried out on the samples to study the mechanical stability of the grown crystals.

Al-substituted ZnMg mixed ferrite prepared by conventional sol-gel method. Al substituted ZnMg ferrite of molecular formula Zn0.7Mg0.3AlxFe2-xO4 & Zn0.5Mg0.5AlxFe2-xO4 where (x=0.0, 0.1, 0.2, 0.3, 0.4) were prepared. The obtained samples were sintered at 8500C for 4 hours. The XRD used to study the structural properties such as particle size, lattices constant and the effect of doping concentration of Al atoms is discussed. The Structural images from XRD, SEM were presented. The Electrical characteristics of these mixed ferrites were studied using Cyclic Voltometric Analysis to measure logarithm of conductivity (log ?), dielectric constant ( ?) and loss factor at various frequencies and are reported. Hopping of electrons between localized stated of cations in the interstitial sites were discussed. The variation of activation energy with various ranges of frequencies was reported.

Single crystals of methyl para hydroxyl benzoate a nonlinear optical (NLO) material were grown by slow solvent evaporation technique at room temperature. Acetone was used as solvent. The MPHB crystals obtained by the above technique were subjected to different characterization analysis. Unit cell parameters were evaluated by single crystal X-ray diffraction technique. The lattice dimensions were determined from the powder x-ray diffraction analysis. The functional groups and optical behaviour of the crystals were identified from FTIR and UV-vis analysis. Micro hardness, thermal and etching studies were also carried out on the sample respectively. The SHG efficiency of the grown crystal was measured through NLO studies.