Wyniki wyszukiwania - Biblioteka Nauki

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Growth and study of nonlinear optical crystals at the Hungarian Academy of Sciences

100%

Földvári I. , Polgár K. , Péter A. , Beregi E. , Szaller Z.

Journal of Telecommunications and Information Technology

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2000

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tom nr 1-2

37-41

EN

The former Research Laboratory for Crystal Physics continues the growth and defect structure investigation of nonlinear optical single crystals in a new organization, as a part of the Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences. The aim of the activity is to prepare specific crystals for basic and applied research as well as for applications. We improve the quality or modify the properties of well known nonlinear oxide and borate crystals and develop new materials. The principle nonlinear optical crystals in our profile are the followings: Paratellurite (TeO2), congruent, Mg-doped and stoichiometric lithium niobate (LiNbO3), a variety of sillenite structured crystals (Bi12MeO20, Me=Si, Ge, Ti, etc.), bismuth tellurite (Bi2TeO5) and nonlinear borates (BBO-beta-BaB2O4, LBO-LiB3O5, LTB-Li2B4O7, CLBO-CsLiB6O10 and YAB-YAI3(BO3)4). Details of the crystal preparation and the major achievements are discussed in the paper.

2

Growth, structural and optical properties of novel nonlinear optical potassium phthalate di lithium borate (KPDLiB) single crystals

80%

Mohanraj K. , Balasubramanian D. , Jhansi N.

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tom Vol. 38, No. 2

214--218

EN

Novel nonlinear optical semi-organic, potassium phthalate di lithium borate (KPDLiB) single crystals were successfully grown by the slow solvent evaporation technique. Good crystalline nature and an orthorhombic structure were confirmed by powder X-ray diffraction and single crystal X-ray diffraction studies. The functional groups of KPDLiB were identified using FT-IR spectrum recorded in the range of 4000 cm-1 to 450 cm-1. UV-Vis spectrum showed transmitting ability of the crystals in the entire visible region. The photoluminescence spectrum exhibited good fluorescence emission in a visible region at 384 nm, 416 nm and 578 nm. The second harmonic generation efficiency of the grown crystal was evaluated from Kurtz powder technique.

3

Growth and characterization of an NLO material - crystal of triglycine acetate

80%

Hussaini S. S. , Dhumane N. R. , Dongre V. G. , Shirsat M. D.

Materials Science Poland

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2009

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tom Vol. 27, No. 2

365--372

EN

Triglycine acetate (TGAc), a nonlinear optical material, has been synthesized. The second harmonic generation efficiency has been determined by Kurtz's powder test and it was found to be 1.55 times more than potassium dihydrogen phosphate. The solubility studies were carried out in the temperature range 30-55 °C. Single crystals of TGAc have been grown by slow evaporation of solution at 30 °C. The cell parameters were determined by the X-ray diffraction analysis. The UV-visible absorption spectra have been recorded to study the optical transmittance in the range from 200 nm to 800 nm. The Fourier transform infrared analysis identified various functional groups present in the material. The mass spectral analysis was carried out to measure the total molecular weight of the grown crystal. Using thermogravimetric analysis the thermal behaviour was studied.

4

Comparative analysis on microhardness and third order nonlinear optical traits of pure and Nd3+ doped zinc tris-thiourea sulphate (ZTS) crystal

80%

Anis M. , Muley G. G. , Shkir M. , Alfaify S. , Ghramh H. A.

Materials Science Poland

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2018

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tom Vol. 36, No. 3

403--408

EN

Based on some advantageous properties, such as fast response time, environment friendliness, small size, long lifetime, and high efficiency, white LEDs are increasingly used in common illumination applications. In this research, by co-doping of redemitting Sr2Si5N8:Eu2+ phosphor and adding SiO2 particles to yellow-emitting YAG:Ce phosphor compounds, a new approach for improving color uniformity and color rending index of remote-phosphor structure white LEDs is proposed and demonstrated. The obtained results clearly indicate that the color rendering index (CRI) and color uniformity (DCCT) significantly depend on Sr2Si5N8:Eu2+ concentration. The results provide a potential practical solution for manufacturing remote-phosphor white LEDs (RP-WLEDs) in the near future.

5

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

70%

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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tom 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.

6

Synthesis, growth, structural, thermal and third order nonlinear optical properties of novel organic single crystal: 4-methylpyridinium 3-nitrophthalate

70%

Reena Devi S. , Suresh S. , Kalaiyarasi S. , NizamMohideen M. , Mohan Kumar R.

Materials Science Poland

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2018

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tom Vol. 36, No. 4

597--608

EN

A novel 4-methylpyridinium 3-nitrophthalate (4MP3NP) was synthesized and the crystals were grown by using slow evaporation method. The structural data of the grown crystal was collected by single crystal X-ray diffraction. It revealed that the 4MP3NP crystal belongs to triclinic crystal system with a space group P1. Structure of the synthesized compound was established using SHELXL 97 program package. The crystalline nature and composition of the grown crystal was established using high resolution X-ray diffraction and FT-IR analyses. UV-Vis transmittance and photoluminescence studies revealed the optical transmission window and electronic transition mechanism of ions, respectively. The laser damage threshold of the grown crystal was estimated by Nd:YAG laser and these results were mutually related to specific heat capacity of the grown crystal. The third-order nonlinear optical susceptibility of the grown crystal was studied by Z-scan technique.

7

Structural, optical, morphological and SHG studies on 8 MeV electron beam irradiated Sr(HCOO)2·2H2O crystal

60%

Muthupoongodi S. , Manickam S. T. D. , Mahadevan C. K. , Greena J. A. M. , Balakumar S. , Ananthapadmanabhan P. V. , Shajan X. S.

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tom Vol. 38, No. 2

236--247

EN

Strontium formate dihydrate single crystals have been grown by the slow solvent evaporation method and subjected to 8 MeV electron beam (EB) irradiation at different doses, viz. 1 kGy, 10 kGy, 50 kGy and 100 kGy. The irradiated crystals have been studied by various techniques such as FT-IR, Raman, and UV-Vis-NIR spectral analyses, powder, and high resolution X-ray diffraction, thermogravimetric analysis (TG/DTA) and second harmonic generation (SHG) measurements. The morphological features of the non-irradiated and irradiated crystals were analyzed by SEM and optical microscopy studies. It has been noticed that the SHG efficiency increases while the crystalline perfection and thermal stability of the irradiated crystals decrease with the increase of EB irradiation dose. The results indicate a significant overall tuning of physical properties of strontium formate dihydrate crystals due to irradiation.