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Your search keyword '"Lukasiewicz, T."' showing total 70 results
Start Over Author "Lukasiewicz, T." Publisher elsevier b.v.
70 results on '"Lukasiewicz, T."'

37. Czochralski crystal growth, microstructure and spectroscopic properties of PrAlO3 perovskite

Author

Pawlak, D.A., Lukasiewicz, T., Carpenter, M., Malinowski, M., Diduszko, R., and Kisielewski, J.

Subjects
*PEROVSKITE, *CRYSTAL growth, *OXIDE minerals, *MICROMECHANICS
Abstract

Abstract: Praseodymium-aluminum (PrAlO3) perovskite crystals have been grown by the Czochralski method for the first time, to our knowledge. An almost periodic microtwin structure has been observed in the as-grown crystals, and a three-dimensional texturing of the polished surfaces has been observed. Optical absorption and emission spectra have been investigated at room temperature for crystals containing only Pr3+ ions as well as for crystals containing a mixture of Pr3+/Pr4+ ions. The observed broad emission band for the as-grown crystals could lead to a future potential application as a tunable laser for the whole visible range. [Copyright &y& Elsevier]

Published
2005
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38. Influence of the rare-earth doping on the photoinduced EOEs in the GdCOB

Author

Lukasiewicz, T., Majchrowski, A., Kityk, I.V., and Kroog, J.

Subjects
*IONS, *RARE earth metals
Abstract

We have discovered a photoinduced linear electrooptic effect (EOE) in the GdCOB doped by the rare-earth ions of the Tm3+ and Sm3+. We have found that doping by Tm3+ is essentially more efficient for increasing EOE compared with the Sm3+ ones. Moreover, increasing Sm3+ content diminishes the values of the r23 electrooptics coefficient. For comparison, the corresponding values for the pure GdCOB are nonsensitive to UV-pumping power and maximal EOE is less than 0.3 pm/V. [Copyright &y& Elsevier]

Published
2003
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39. Influence of the rare-earth doping on the photoinduced EOEs in the GdCOB

Author

Lukasiewicz, T., Majchrowski, A., Kityk, I.V., and Kroog, J.

Subjects
*RARE earth metals, *ELECTROOPTICS
Abstract

We have discovered a photoinduced linear electrooptics effect (EOE) in the GdCOB doped by the rare earth ions of Tm3+ and Sm3+. We have found that doping by Tm3+ is essentially more efficient for increasing EOE compared with the Sm3+ ones. Moreover, increasing the Sm3+ content diminishes the values of the r23 electrooptics coefficient. For comparison, the corresponding values for the pure GdCOB are non-sensitive to UV pumping power and maximal EOE is less than 0.3 pm/V. [Copyright &y& Elsevier]

Published
2002

40. New oxide crystal (La,Sr)(Al,Ta)O3 as substrate for GaN epitaxy

Author

Lukasiewicz, T., Řwirkowicz, M., Sakowska, H., Turos, A., Leszczyński, M., and Ratajczak, R.

Subjects
*CRYSTAL growth, *CRYSTALLIZATION, *CRYSTALS, *SOLIDS
Abstract

A new candidate single crystal (La,Sr)(Al,Ta)O3 (LSAT) as a substrate for GaN epitaxial growth was found. Mixed-perovskite (1 1 1) oriented crystals were successfully grown by conventional Czochralski method. Excellent lattice matching with gallium nitride makes this material specially promising. Determination of the lattice parameters and the phase identification obtained crystals by X-ray diffraction analysis was carried out. Thermal expansion, thermal conductivity and electrical conductivity were measured. GaN epitaxial layers have been grown on (1 1 1) LSAT substrate and the results are presented. [Copyright &y& Elsevier]

Published
2002

41. Influence of Ca4GdO(BO3)3 doping on its properties

Author

Lukasiewicz, T., Kityk, I.V., Makowska-Janusik, M., Majchrowski, A., Galązka, Z., Kaddouri, H., and Mierczyk, Z.

Subjects
*CRYSTALLOGRAPHY, *INTERMEDIATES (Chemistry), *PROPERTIES of matter, *SPECTRUM analysis
Abstract

Czochralski growth of Ca4GdO(BO3)3 (GdCOB) single crystals, pure and doped with several rare earth ions (Nd3+, Pr3+, Tm3+, and Sm3+), has been carried out. As-grown single crystals free from inclusions, bubbles and cracks were 20 mm in diameter and up to 60 mm in length. Optical absorption spectra of 6 at% thulium and samarium doped calcium gadolinium oxoborate were measured and presented. It was found that introduction of Pr3+ and Tm3+ ions leads to an increase of second-order photoinduced effects in GdCOB. The second harmonic generation shows an increase of at least 35% under the influence of photoinducing nitrogen laser (λ=377 nm) power. [Copyright &y& Elsevier]

Published
2002

44. Acoustically induced optical effects in Pr3+ and Tm3+ doped calcium gadolinium oxyborate nanocomposites

Author

Lukasiewicz, T., Kisielewski, J., Lipinska, L., Majchrowski, A., Lakshminarayana, G., and Kityk, I.V.

Subjects
*OPTICAL properties of metals, *METAL ions, *SEMICONDUCTOR doping, *ACOUSTICAL materials, *BORATES, *NANOCOMPOSITE materials, *TEMPERATURE effect, *NANOCRYSTALS, *KERR electro-optical effect
Abstract

Abstract: Acoustically induced two-photon absorption (AITPA) and optical Kerr effect (AIOKE) in Pr and Tm doped calcium gadolinium oxyborate Ca4GdO(BO3)3 (CGOB) nanocrystallites (with sizes below 60nm) prepared by sol–gel method and embedded into the PMMA matrices were studied. The source of the acoustical field generated the frequency equal to about 1.2MHz and achieved maximal acoustical power density equal to about 6W/cm2. The AITPA was measured at fundamental Er:glass laser wavelength (1.54μm) and was observed only during applying of the prolonged acoustical field. The AITPA effect was substantially higher for the Tm3+ doped composites than for the Pr3+ doped ones. With increasing acoustical power, the AITPA increases achieving its maximal value at acoustical power density equal to about 4.70W/cm2. Temperature dependences have demonstrated the maximal values of the AITPA at temperatures equal to about 310K corresponding to the AITPA value equal to about 3.4cm/GW. At the same time at acoustical power density about 3.8W/cm2 the AIOKE achieves its minimum for the Pr doped CGOB nanocomposites. So one can expect that these two effects have different signs of contribution caused by the acoustical field. [Copyright &y& Elsevier]

Published
2011
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