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).

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.

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.

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.

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.

The present paper reports the growth of Urea Thiourea Potassium Sulphate crystal (UTKS) by slow evaporation method at 30 °C. A Single and Powder X-ray diffraction analysis reveals that UTKS crystals belong to orthorhombic structure at various diffracting planes of the grown crystal were identified. In various functional groups of the grown UTKS crystal were identified by FT-IR spectral analysis. Optical transmittance and energy band gap of grown crystal have been measured from UV-Vis studies. Second harmonic generation was investigated to confirm the non-linear optical properties. The thermal behavior has been examined by TG/DTA analysis and the SEM images of the crystal reveal the well formation of the faces of the crystal. Keywords FT-IR, SHG, SEM analysis, Single and Powder XRD, TG/DTA and UV-Vis.

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.

L-Valinium Picrate, Rare earth element Erbium doped L-Valinium Picrate and soft transition element Cobolt doped L-Valinium Picrate were synthesized and grown as single crystals by slow evaporation method. The cell dimensions were obtained by single-crystal X-ray diffraction study. Optical properties, such as UV–visible–NIR absorption and second harmonic generation conversion efficiency were investigated to explore the optical characteristics of the grown crystals. Microhardness, Thermal and dielectric studies of the compound were also carried out. 

The Erbium doped KDP crystals were grown by Sankaranarayanan-Ramasamy (SR) method with the vision to improve the properties of the crystal. The chemical composition of the grown crystals is confirmed by EDAX Analysis. The grown crystal was characterized by PXRD and UV-Vis analysis. The SHG efficiency is determined by Kurtz powder technique. The dielectric constant, dielectric loss and ac conductivity of the crystal were studied. The functional groups are identified by FT-Raman analysis. The Optical transmission and SHG studies shows the suitability of the ingot for optical applications.