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Structural, spectral, electrical, Z-scan and HOMO LUMO studies on new 2-amino-6-methylpyridinium 2-hydroxybenzoate crystal

Punithaveni B., Thilagavathy K., Muthukumarasamy N., Nithyaprakash D., Saravanabhavan M.

Materials Science Poland

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2018

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Vol. 36, No. 4

537--546

EN

New organic single crystals of 2-amino-6-methylpyridinium 2-hydroxybenzoate (2A6M2H) were grown by slow evaporation solution growth technique at room temperature. The grown crystal structure was studied using single crystal XRD. Crystalline nature and phases were confirmed by powder XRD analysis. FT-IR study was used to identify the functional groups present in the compound. UV-Vis study revealed that the lower cut off wavelength of the crystal is at 350 nm. The dielectric studies indicated the low value of dielectric loss at high frequency. Mechanical properties of the crystals were studied using Vickers microhardness test. The Z-Scan studies were conducted for the crystal using He–Ne laser.

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Linear-nonlinear optical, dielectric and surface microscopic investigation of KH2PO4 crystal to uncover the decisive impact of dopant glycine

Khan I., Kalainathan S., Baig M. I., Shkir M., Alfaify S., Ghramh H. A., Anis M.

Materials Science Poland

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2018

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Vol. 36, No. 4

662--667

EN

Present investigation has been started to perform the comparative study of pure and glycine doped KH2PO4 (KDP) single crystals grown by most commercial slow solvent evaporation technique. The grown crystals were subjected to single crystal X-ray diffraction analysis to determine their structural parameters. The linear optical studies of pure and glycine doped KDP crystal have been undertaken within 200 nm to 1100 nm wavelength range by means of UV-Vis studies. The enhancement in second harmonic generation (SHG) efficiency of glycine doped KDP crystal has been determined using a standard Kurtz-Perry powder test. The dielectric measurements have been carried out to explore the impact of glycine dopant on dielectric constant and dielectric loss of KDP crystal. The surface growth habitat and etch pit density of glycine doped KDP crystal have been evaluated using the results of microscopic etching studies. In light of obtained results the suitability of glycine doped KDP crystal for device applications has been discussed.

3

Synthesis, growth and characterization of organic crystal triphenylmethane p-nitroaniline: a nonlinear optical crystal

Bhuvaneswari G., Prasad L. G., Prabhavathi N.

Materials Science Poland

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2017

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Vol. 35, No. 3

667--672

EN

A triphenylmethane-4-nitroaniline salt has been synthesized and the crystals have been grown by using slow evaporation solution growth technique. The grown single crystal was investigated by recording the powder XRD, FT-IR spectrum, UV-Vis spectrum, Vickers microhardness test, dielectric measurements and powder SHG. The growth of crystal was confirmed by analyzing the XRD pattern and it was stated that the grown material crystallized in triclinic system. Vibrational peaks of the functional groups existing in the compound were identified. Vickers microhardness studies were carried to measure the mechanical strength. In order to identify the phase transition temperature, the dielectric studies were carried out at different temperatures. Dielectric constant, dielectric loss and impedance of the crystal were monitored with respect to the frequency of electric field.

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Investigation on nonlinear optical and dielectric properties of L-arginine doped ZTC crystal to explore photonic device applications

Anis M., Hussaini S. S., Shirsat M. D., Muley G. G.

Materials Science Poland

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2016

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Vol. 34, No. 3

548--554

EN

The present study is focused to explore the photonic device applications of L-arginine doped ZTC (LA-ZTC) crystals using nonlinear optical (NLO) and dielectric studies. The LA-ZTC crystals have been grown by slow evaporation solution technique. The chemical composition and surface of LA-ZTC crystal have been analyzed by means of energy dispersive spectroscopy (EDS) and surface scanning electron microscopy (SEM) techniques. The Vicker’s microhardness study has been carried out to determine the hardness, work hardening index, yield strength and elastic stiffness of LA-ZTC crystal. The enhanced SHG efficiency of LA-ZTC crystal has been ascertained using the Kurtz-Perry powder SHG test. The closed-and-open aperture Z-scan technique has been employed to confirm the third order nonlinear optical nature of LA-ZTC crystal. The Z-scan transmittance data has been utilized to calculate the superior cubic susceptibility, nonlinear refractive index, nonlinear absorption coefficient and figure of merit of LA-ZTC crystal. The behavior of dielectric constant and dielectric loss of LA-ZTC crystal at different temperatures has been investigated using the dielectric analysis.

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Dielectric, etching and Z-scan studies of glycine doped potassium thiourea chloride crystal

Azhar S. M., Anis M., Hussaini S. S., Kalainathan S., Shirsat M. D., Rabbani G.

Materials Science Poland

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2016

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Vol. 34, No. 4

800--805

EN

Glycine doped potassium thiourea chloride (PTC) crystal has been grown by slow solution evaporation technique. The dielectric studies have been employed to examine substantial improvement in dielectric constant and dielectric loss of glycine doped PTC crystal. The etching studies have been performed to investigate the surface quality of this crystal. The z-scan studies have been carried out at 632.8 nm to explore the third order nonlinear optical nature. The negative nonlinear refraction of glycine doped PTC crystal was found to be of 7.27 × 10-12cm2/W. The origin of high magnitude of third order nonlinear optical susceptibility and reverse saturable nonlinear absorption have been investigated. The obtained results were explored to discuss the nonlinear optical applications of PTC crystal.

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Właściwości termiczne i dielektryczne silseskwioksanów z azowymi ugrupowaniami mezogenicznym

Mossety-Leszczak B., Włodarska M., Galina H., Dutkiewicz M.

Polimery

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2013

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T. 58, nr 10

733--740

PL

W reakcji hydrosililowania estrów monowinylowych z azobenzenową grupą mezogeniczną, oktakis(wodorodimetylosiloksy)oktasilseskwioksanem, w obecności katalizatora Karstedta zsyntezowano dwa sferokrzemiany z grupami mezogenicznymi. Otrzymane produkty różniły się długością alifatycznych łańcuchów łączących klatkę POSS z grupami mezogenicznymi. Właściwości termiczne i przejścia fazowe uzyskanych pochodnych określano metodą termograwimetrii (TGA), skaningowej kalorymetrii różnicowej (DSC), optycznej mikroskopii polaryzacyjnej (POM) i spektroskopii dielektrycznej (DRS). Stwierdzono, że właściwości ciekłokrystaliczne zarówno w czasie grzania, jak i chłodzenia wykazuje tylko sferokrzemian z dłuższymi łańcuchami alifatycznymi (C10) pomiędzy nieorganiczną klatką POSS a grupami mezogenicznymi. Materiał ten w badaniach dielektrycznych wykazywał dodatkowy proces relaksacyjny związany z większą ruchliwością grup mezogenicznych.

EN

Two spherosilicates having mesogenic moieties were synthesized by hydrosilylation reaction between octakis(hydridodimethylsiloxy)octasilsesquioxane and monovinyl esters with azobenzene mesogenic groups using Karstedt's catalyst. The synthesized silsesquioxanes differed in the length of aliphatic chains connecting the POSS cage with mesogenic groups. The thermal properties and phase behavior of the products were studied using termogravimetric analysis (TGA), differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and dielectric relaxation spectroscopy (DRS). The results show that only the spherosilicate with longer aliphatic spacers (C10) between inorganic cage and mesogenic groups exhibits stable liquid crystalline phases during both cooling and heating. This material also shows an additional relaxation process in the dielectric studies, which has been attributed to the higher mobility of mesogenic groups.