Czestochowa Technological University

Częstochowa, Poland

Czestochowa Technological University

Częstochowa, Poland

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Majchrowski A.,Military University of Technology | Klosowicz S.,Military University of Technology | Jaroszewicz L.R.,Military University of Technology | Swirkowicz M.,Institute Of Electronic Materials Technology of Poland | And 3 more authors.
Journal of Alloys and Compounds | Year: 2010

NdAl3(BO3)4 single crystals with different concentrations of Yb3+ were grown using the top seeded solution growth method. The absorption spectra of the grown samples were recorded at room temperature and analyzed using the standard Judd-Ofelt theory. Influence of Yb3+ concentration on the Nd3+ absorption properties was studied. Variation of the Nd3+ oscillator strengths with changing Yb3+ concentration suggests significant role of the Yb-Nd energy transfer in the formation of the absorption spectra. Following the absorption spectra we illuminated the investigated crystals at 532 nm absorption line to observe the changes of the two-photon absorption (TPA). We observed substantial increase of the TPA with the increased power of the illuminating laser which was proportional to the Yb content. © 2009 Elsevier B.V. All rights reserved.


Majchrowski A.,Military University of Technology | Jaroszewicz L.R.,Military University of Technology | Swirkowicz M.,Institute Of Electronic Materials Technology of Poland | Miedzinski R.,ugosz University | And 4 more authors.
Materials Letters | Year: 2010

RbNd(WO4)2 single crystals with different concentrations of Yb3+ have been grown using the top seeded solution growth. Room-temperature absorption spectra were assigned on the basis of the Dieke's diagram for Nd3+ ion and analyzed by means of the standard Judd-Ofelt theory. It was shown that the increase of the Yb3+ concentration and corresponding decrease of the Nd3+ concentration leads to the increase of the corresponding Judd-Ofelt intensity parameters, which suggests significant contribution of the Yb-Nd energy transfer in the formation of the absorption spectra. © 2009 Elsevier B.V. All rights reserved.


Majchrowski A.,Military University of Technology | Swirkowicz M.,Institute Of Electronic Materials Technology of Poland | Ozga K.,Czestochowa Technological University | Kityk I.V.,Czestochowa University of Technology | Kityk I.V.,King Saud University
Optics Communications | Year: 2010

The dispersion of the piezooptical coefficients induced by external light for neodymium-containing NdGaO3, K5Nd(MoO4)4, α-RbNd(WO4)2, and NdAl3(BO3)4 crystals was discovered. As a pumping laser we have used Nd:YAG laser possessing power density varying from 0.2 up to 1 GW/cm2, pulse duration 15 ns and frequency repetition 10 Hz. The dispersion of the piezooptical coefficients was evaluated in the spectral range 450-910 nm. We have found that illumination by the laser pulses with power density up to 1 GW/cm2 cause substantial changes of the piezooptical coefficients in these crystals. However, behaviour of the obtained dependences is substantially different for all the compounds. The possible origins of the observed effects are considered. © 2009 Elsevier B.V. All rights reserved.


Kassab L.R.P.,São Paulo State Technological College | K. Ozga,Czestochowa Technological University | Da Silva D.M.,University of Sao Paulo | Miedzinski R.,ugosz University Of Czestochowa | Slezak A.,Czestochowa Technological University
Optics Communications | Year: 2010

We have found photoinduced second harmonic generation at wavelength 1064 nm during bicolor Nd:YAG laser coherent treatment of TeO2-ZnO and GeO2-PbO amorphous films. The maximally achieved second order susceptibility was equal to about 1.02 pm/V. Correlation of the induced second order susceptibility with local sample heating and induced birefringence may indicate an occurrence of local phase transitions from amorphous glass-like phase to non-centrosymmetry metastable phases. © 2010 Elsevier B.V. All rights reserved.


Zhbankov O.,Lesya Ukrainka Eastern European National University | Fedorchuk A.,Lviv National University of Veterinary Medicine and Biotechnologies | Kityk I.,Czestochowa Technological University | Olekseyuk I.,Lesya Ukrainka Eastern European National University | Parasyuk O.,Lesya Ukrainka Eastern European National University
Journal of Alloys and Compounds | Year: 2011

The crystal structure of the ternary compound Ag2SiS3 was determined on the basis of X-ray powder diffraction. The compound belongs to a new structure type, space group P21/c, a = 0.66709(1), b = 0.66567(2), c = 1.31748(3) nm, and β = 118.658(1)°. Ag 2SiS3 contains isolated [Si2S6] anionic units consisting of pairs of edge-shared tetrahedra. The Ag atoms are situated in the interstices formed by these fragments. © 2010 Elsevier B.V. All rights reserved.


Lakshminarayana G.,Nagoya Institute of Technology | Nogami M.,Nagoya Institute of Technology | Kityk I.V.,Czestochowa Technological University
Journal of Alloys and Compounds | Year: 2011

New composite membranes consisting of phosphosilicate (P2O 5-SiO2) content and 1-ethyl-3 methylimidazolium tetrafluoroborate [EMIMBF4] ionic liquid were fabricated by sol-gel process. For all the prepared hybrid membranes, the interaction between the doped "hydrophilic" [EMIMBF4] ionic liquid and the inorganic phosphosilicate network was investigated by Fourier transform infrared spectroscopy. Average pore sizes and specific surface areas were investigated by the Brunauer-Emmett-Teller (BET) method. Thermogravimetry (TG) and differential thermal analysis (DTA) measurements confirmed that the hybrid membranes were thermally stable up to 220 °C. Relatively a high conductivity of 1 × 10-2 S/cm (8.9 × 10-3 S/cm for 40 wt% IL doped 60TMOS-30VTMOS-10PO(OCH3)3 (mol%) hybrid membrane) was obtained for 40 wt% IL doped 30TMOS-30TEOS-30MTEOS-10PO(OCH 3)3 hybrid membrane, at 155 °C under anhydrous conditions. The hydrogen permeability was found to decrease within the range 10-11 to 10-12 mol/cm s Pa for 40 wt% IL doped membranes as the temperature increases from 20 to 150 °C. © 2010 Elsevier B.V. All rights reserved.


Avram N.M.,West University of Timișoara | Avram N.M.,Academy of Romanian Scientists | Brik M.G.,University of Tartu | Kityk I.V.,Czestochowa Technological University
Optical Materials | Year: 2010

A detailed microscopic study of the crystal field strength 10Dq for different interionic distances in cubic ZnS:V2+ and MgO:Cr 3+ single crystals was performed. The exchange charge model of crystal field was used to calculate the 10Dq values for different distances between the impurity ions and ligands. The obtained results were extrapolated by the power laws 10Dq ∼ 1/Rn, with n = 4.4208 for ZnS:V 2+ and n = 6.4009 for MgO:Cr3+. With these 10Dq(R) dependencies, a number of important physical quantities describing the optical and dynamical properties of impurity centers (such as the constants of the electron-vibrational interaction, Huang-Rhys parameters, Stokes shifts, Jahn-Teller stabilization energies) were estimated and compared with available literature data. © 2010 Elsevier B.V. All rights reserved.


Lakshminarayana G.,Nagoya Institute of Technology | Nogami M.,Nagoya Institute of Technology | Kityk I.V.,Czestochowa Technological University
Journal of the Electrochemical Society | Year: 2010

In this paper, we report on inorganic-organic composite membranes with anhydrous proton conduction prepared by the sol-gel process with tetraethoxysilane/ethyl-triethoxysilane/trimethylphosphate and 1-butyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide ([BMI][BTSI]) ionic liquid as precursors. The Fourier transform IR spectroscopy, 31P, 1H, and 13C NMR, and thermogravimetric and differential thermal analysis measurements confirmed that the membranes possess good chemical stability and are thermally stable up to 310°C. Thermal stability was considerably enhanced by the presence of the inorganic SiO 2 framework and the stability of [BTSI] anion. The conductivity of all the fabricated membranes was measured from -30 to 150°C, and a high conductivity of 5× 10-3 S/cm was measured for the 40 wt % [BMI][BTSI] ionic liquid doped membrane at 150°C under anhydrous conditions. The hydrogen permeability was decreased from 1.84× 10-11 to 2.7× 10-12 mol/cm s Pa for the 40 wt % [BMI][BTSI] ionic liquid doped hybrid membrane during temperature increment from 20 to 150°C. For 40 wt % ionic liquid doped hybrid membrane, membrane electrode assemblies were fabricated, and a maximum power density value of 0.17 mW/ cm2 at 0.42 mA/ cm2 as well as a current density of 0.67 mA/ cm2 were achieved at 150°C under nonhumidified conditions. © 2010 The Electrochemical Society.


Lakshminarayana G.,Nagoya Institute of Technology | Nogami M.,Nagoya Institute of Technology | Kityk I.V.,Czestochowa Technological University
Energy | Year: 2010

We report on anhydrous proton conducting inorganic-organic composite membranes synthesized from tetraethoxysilane/poly(-dimethylsiloxane)/trimethylphosphate and 1-ethyl-3 methylimidazolium-bis (trifluoromethanesulfonyl) imide ionic liquid as sol-gel precursors. The Fourier transform infrared spectroscopy, 31P, 1H, and 13C Nuclear magnetic resonance, thermo gravimetric and differential thermal analysis measurements confirmed that the prepared hybrid membranes possess good chemical stability and are thermally stable up to 350 °C. Conductivity of all the fabricated hybrid membranes was measured under anhydrous conditions within the temperature range -20-150 °C, and a value of 4.87 × 10-3 S/cm at 150 °C was achieved for 40 wt% [EMI][TFSI] ionic liquid doped 72TEOS-18PDMS-10PO (OCH3)3 (mol %) hybrid membrane. For 40 wt% ionic liquid doped composite membrane, the measured hydrogen permeability value at 150 °C was 4 × 10-12 mol/cm s Pa. © 2010 Elsevier Ltd.


Romanyuk Y.E.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Marushko L.P.,European University at Kiev | Piskach L.V.,European University at Kiev | Kityk I.V.,European University at Kiev | And 4 more authors.
CrystEngComm | Year: 2013

While record solar cells based on Cu(In,Ga)Se2 (CIGS) absorbers exhibit the highest conversion efficiencies among all thin film photovoltaic technologies, the structural nature of the electronically favourable heterojunction CIGS-CdS is still debatable. Here, we present an investigation of the phase equilibria in the full Cu(In,Ga)(S,Se)2-2Cd(S,Se) quaternary exchange system at the selected annealing temperature of 870 K in order to reveal the formation of intermediate solid solutions. There are three single phase regions in the system: the chalcopyrite α-solid solution based on Cu(In,Ga)(S,Se)2, the wurtzite β-solid solution of Cd(S,Se), and the intermediate γ-solid solution existing in a zinc blende structure. The γ-phase has a broad homogeneity range and crystallizes in the cubic space group F43m with a statistical distribution of metal atoms in the cation sub-lattice. © 2013 The Royal Society of Chemistry.

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