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Kashuba A.I.,Ifranko National University Of Lviv | Franiv A.V.,Ifranko National University Of Lviv | Bovgyra O.V.,Ifranko National University Of Lviv | Brezvin R.S.,Ifranko National University Of Lviv
Functional Materials | Year: 2017

The results of investigation of optical properties of the newly synthesized solid solution InxTI1-xI in concentration range of 0.4≤x≤0.7 are presented. Birefringence is measured for InxTI1-xI solid state solution. Dependence of the birefringence A.nt on the concentration of thallium iodide is investigated. Dielectric permeability distribution ε(E) is calculated using pseudopotential method in the framework of density functional theory. The real ε1 and imaginary e2 parts of the dielectric constant are calculated for polarization E∥a. and E∥c over a range of photon energy from 0 to 14 eV. The spectra show pronounced anisotropy between these polarizations. Spectral dependences of the birefringence Δ.nt of InxTI1-xI crystals for various physical crystal directions are obtained based on these calculations. The experimental and theoretical birefringence spectra are in a good agreement. © 2017. STC "Institute for Single Crystals". All rights reserved.


Pushak A.S.,Ukrainian Academy of Printing | Vistovskyy V.V.,Ifranko National University Of Lviv | Myagkpta S.V.,Lviv State Agrarian University | Demkiv T.M.,Ifranko National University Of Lviv | And 4 more authors.
Functional Materials | Year: 2010

The formation of SrCl2-Eu microcrystals embedded in NaCl host has been demonstrated for NaCl-SrCl2(l mol.%)-EuCl3(0.02 mol.%) composition. The size of SrCl2-Eu microcrystals is in the 1-10 μm range. The spectral and luminescence properties of NaCl-Eu(0.1 mol.%), SrCl2-Eu(0.1 mol.%) and NaCl-SrCl2(l mol.%)-3(0.02 mol.%) crystals under optical and X-ray excitation have been studied. The luminescence parameters of SrCl2-Eu microcrystals embedded in NaCl host are revealed to be substantially similar to those of SrCl2-Eu(0.1 mol.%) single crystal. © 2010 - STC "Institute for Single Crystals".


Zhyshkovych A.V.,Ifranko National University Of Lviv | Vistovskyy V.V.,Ifranko National University Of Lviv | Mitina N.E.,Lviv Polytechnic | Zaichenko A.S.,Lviv Polytechnic | And 2 more authors.
Functional Materials | Year: 2014

CaF2 CaF2: Eu2+ and CaF2:Eu3+ nanoparticles were synthesized by the chemical sedi-mentation method. The study of intrinsic and impurity recombination luminescence of the nanoparticles was carried out using synchrotron radiation. The intrinsic and impurity luminescence intensity was found to depend significantly on the nanoparticles size. The surface defects, the ratio between the thermalization length of photoelectrons and the nanoparticle size are crucial for luminescence intensity of the nanoparticles. The lumines-cense caused by the charge-transfer to Eu3+ ions is dominant for the small size nanoparticles. © 2014-STC "Institute for Single Crystals".


Stetsyk N.V.,Ifranko National University Of Lviv | Antonyuk V.G.,Ifranko National University Of Lviv | Rudka M.M.,Lviv Polytechnic
Functional Materials | Year: 2014

Temperature behaviors of X-ray luminescence, photoluminescence, and thermolumines-cence were studied in cadmium bromide crystals doped with impurities of argentum from room temperature to liquid nitrogen temperature. It was found that the cadmium bromide crystals doped with impurities of argentum are sensitive to action of X-rays and ultravio{reversed not sign}let light owing to the flow of photochemical reactions in these crystals. © 2014 - STC "Institute for Single Crystals".


Pushak A.S.,Ukraine Academy of Printing | Vistovskyy V.V.,Ifranko National University Of Lviv | Demkiv T.M.,Ifranko National University Of Lviv | Datsyuk Y.R.,Ifranko National University Of Lviv | And 4 more authors.
Functional Materials | Year: 2015

Luminescence-kinetic properties of Lal3-Ce microcrystals of 1-10 μm size in Nal-Lal3-Ce system are studied upon 2.5-12 eV excitation using synchrotron radiation. The luminescent properties of cerium centers in the embedded Lal3-Ce microcrystals are revealed to be similar to those for the bulk Lal3-Ce crystals. The mechanisms of cerium centers luminescence excitation in the Nal-Lal3-Ce crystalline system upon excitation in the transparency and fundamental absorption range of Nal and Lal3 matrixes and mechanisms of thermal quenching of cerium ions luminescence in the Lal3 microcrystals are discussed. © 2015 - STC "Institute for Single Crystals".


Konopelnyk O.I.,Ifranko National University Of Lviv | Aksimentyeva O.I.,Ifranko National University Of Lviv | Dyakonov V.P.,Polish Academy of Sciences | Dyakonov V.P.,Ukrainian Academy of Sciences | And 3 more authors.
Functional Materials | Year: 2013

Method of electrostatic layer-by-layer assembly is used for preparation of the ultra thin functional films based on anionic complex of poly-3.4-ethylene dioxythiophene (PEDOT) - polystyrene sulfoacid (PSS) on the surface of the transparent indium-tin-oxide substrates. For the first time JV-cetyl pyridinium chloride (CPC) was usedas a cationic surfactant. It has been shown that nanofilms obtained in the presence of CPC demonstrate the optical properties and electrochemical behavior similar to PEDOT-PSS functional films that promises their applicationin electrochromic devices.. © 2013-STC " Institute For Single Crystals ".


Antonyak O.T.,Ifranko National University Of Lviv | Voloshinovskii A.S.,Ifranko National University Of Lviv | Vistovskyy V.V.,Ifranko National University Of Lviv | Chornodolskyy Y.M.,Ifranko National University Of Lviv
Functional Materials | Year: 2013

The luminescence excitation and emission spectra of SrCl2:Pr single crystals containing 0.2mol. % Pr were investigated at T = 10K using vacuum ultraviolet synchrotron radiation. From analysis of the fine structure of the low-energy excitation band of an activator, the following main frequencies associated with the local structure of the activator centers were found in the phonon spectrum of SrCl2:Pr crystal: 194; 210; 266 and 298cm-1.© 2013 - STC "Institute for Single Crystals".


Prysyazhnyuk V.,Ifranko National University Of Lviv | Mykolaychuk O.,Ifranko National University Of Lviv
Functional Materials | Year: 2013

Structural and electrophysical studies of thin amorphous and polycrystalline films of Gd-Fe system just after evaporation as well as after 3 years ageing were carried out. The high time stability of these materials has been established. © 2013-STC "Institute for Single Crystal".

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