Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 5

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Optical Characterization of Laser-Synthesized Anatase TiO_{2} Nanopowders by Spectroscopic Ellipsometry and Photoluminescence Measurements

100%
Šćepanović M., Grujić-Brojčin M., Mirić M., Dohčević-Mitrović Z., Popović Z.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 4
603-606
EN
Nanosized titania (TiO_{2}) is synthesized by laser-induced pyrolysis using TiCl_{4} as a liquid precursor. X-ray diffraction and Raman scattering confirmed anatase structure of TiO_{2} nanocrystals. The dielectric function ε(ω) of TiO_{2} nanopowders has been determined by spectroscopic ellipsometry in the energy range from 1.5 to 6 eV at room temperature. The features observed in ε(ω) have been fitted to analytical line shapes by using the second derivatives of experimental spectra. The energies corresponding to different interband electronic transitions have been determined. Photoluminescence measurements have been carried out in vacuum for T = 20 K and T = 300 K. Under laser irradiation with sub-band gap photon energy, anatase nanocrystals have displayed strong visible photoluminescence emission. In this broad photoluminescence band different variations of line shape and position with excitation energy and temperature are observed for nanopowders with different crystallite size, pointing out to the various electronic transitions mediated by defect levels within the band gap.
2
Content available remote

Modelling the Variable Angle Reflection and Transmission from Metamaterial Slabs

86%
Isić G., Vasić B., Mirić M., Jokanović B., Bergmair I., Gajić R., Hingerl K.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 4
631-634
EN
We consider metamaterial slabs composed of perfectly conducting split-ring resonators. Assuming bianisotropic constitutive relations, we describe an S-parameter retrieval method that allows us to obtain the full material parameter tensors from numerically calculated S parameters. The retrieval has been done for various angles of incidence, ranging from 0° to 75°. It has been found that the parameters depend on the angle of incidence, but that this dependence is relatively small.
3
Content available remote

Ellipsometric Measurements of Plastically Deformed Copper

86%
Mirić M., Rudolf R., Anžel I., Hadžić B., Romčević M., Trajić J., Romčević N.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 4
715-717
EN
Chemically pure copper (99.99) prepared in the sample of square cross-section (10×10 mm^{2}) and length about 50 mm was extremely plastically deformed with the repeated application of equal channel angular pressing. Equal channel angular pressing was applied as an effective technique for producing bulk nanoscaled structures. It is well known that severe plastic deformation of metallic materials often leads to microstructure with ultrafine grains and cross-sections which remain about equal before and after deformation. Optical properties of the sample were studied using spectroscopic ellipsometry in UV-VIS range. The parameters of the sample like copper oxide and surface roughness overlayer were calculated using two-film model together with the Bruggeman effective medium approximation.
4
Content available remote

Optical Characterization of Graphene and Highly Oriented Pyrolytic Graphite

86%
Kostić R., Mirić M., Radić T., Radović M., Gajić R., Popović Z.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 4
718-721
EN
We present a symmetry analysis of allowed infrared and Raman modes in graphene and highly oriented pyrolytic graphite. Surface structure for highly oriented pyrolytic graphite is examined using atomic force microscopy. As experimental tools, we used infrared spectroscopic ellipsometry in order to investigate the pseudodielectric function of highly oriented pyrolytic graphite in the mid-infrared range (500-7000 cm^{-1}) and Raman spectroscopy to investigate the influence of layers number decrease. As a result, we propose a method for an experimental verification of graphene.
5
Content available remote

Optical Properties of Plastically Deformed Copper

73%
Trajić J., Rudolf R., Anžel I., Romčević M., Lazarević N., Mirić M., Lazarević Z., Hadžić B., Romčević N.
|
|
issue 5
791-793
EN
Pure copper (99.99), prepared in the sample of square cross-section (10 × 10 mm^{2}) and length about 50 mm, was extremely plastically deformed with the repeated application of Equal Channel Angular Pressing (ECAP). ECAP was applied as an effective technique for producing bulk nano-scaled structures. Optical properties of the sample were investigated using Raman spectroscopy. Two types of lines: narrow (with width of ≈ 7 cm^{-1}) and wide ( ≈ 40 cm^{-1}) are registered. Existence of two types of lines indicates that in the specimen exists nano-sized crystal structures of both Cu and CuO related with three dimensional amorphous boundary spaces, which indicates that plastic deformation of the sample did not lead to total amorphisation of the specimen.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.