Annual Report 2012 - Latvijas Universitātes Cietvielu fizikas institūts

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Modified yarn strength decreases by 30%, which correlated with the moisture content (6-12 %wt). Relative strength at 280 O C yarn with active particles respect to unmodified increased in the direction Cu, Cu 2 O and CuO (fig.4; Fig.5). Fig. 4. Breaking load, 240 o C Fig. 5. Breaking load, 280 o C PREPARATION OF TiO 2 THIN FILMS BY PARTICULATE SOL-ELECTROPHORETIC DEPOSITION G.Bajars, I.Liepina, A. Lusis, J.Gabrusenoks, E. Pentjuss Titanium dioxide thin films have been extensively studied because of their excellent properties for photocatalysis, gas sensors, ultrafiltration membranes, selfcleaning coatings, solar cells and photovoltaic applications. Many efforts have been made to improve their properties by preparing porous films with high surface area. There are a wide variety of preparation methods for TiO 2 thin films, e.g. sol-gel, doctor blade, spin coating, chemical vapor and sputter deposition. In this study nanocrystalline TiO 2 thin films have been prepared by sol-electrophoretic deposition process. The first step was the preparation of TiO 2 sol. Titanium tetra-iso-butoxide (TTIB) was used as a precursor, hydrochloric acid as a catalyst for the peptization and deionized water as a dispersion media. A water-acid mixture was stabilized at 50 °C with continuous stirring. An appropriate amount of TTIB was added next forming the white precipitate that gradually peptized forming a clear sol. For the electrophoresis growth, the Pt anode and cathode are placed parallel in an TiO 2 sol with a distance 1 cm in between. The cathodes used were metallic Cu and Ti, thin Pt layer on silicon, transparent indium tin oxide (ITO) on glass. A constant voltage of 0.5 – 0.6 V was applied by a dc power supply between the electrodes and held for 1 – 3 h. The as-deposited thin films were first dried at 100 °C for 24 h and then heated at a rate of 10 °C/min and were finally annealed at 500 °C for 2 h. Obtained TiO 2 thin films were characterized by phase composition, morphology and their microstructures using X-ray diffraction, Raman spectroscopy, as well as transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The optical properties of TiO 2 thin films were investigate by analyzing I – V curves. The possible correlations between the optical and structural properties of thin films are discussed. TiO2 thin films have been obtained by a sol-electrophoretic deposition method on metallic Ti and Pt substrates. X-ray diffraction, Raman spectroscopy and scanning electron microscopy were used to investigate the structure and morphology of plated materials. Annealed TiO2 films mainly are formed in anatase structure with different morphology depending on substrate material. Light induced potential measurements indicate that the morphology substantially have an impact on photoactivity of TiO2 thin films. 128
CHARACTERIZATION OF LiFePO4/C COMPOSITE THIN FILMS USING ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY G Bajars, G Kucinskis, J Smits, J Kleperis, A Lusis The composite LiFePO4/C thin films were prepared on steel substrate by radio frequency (RF) magnetron sputtering. Electrochemical properties of the obtained thin films were investigated by cyclic voltammetry charge-discharge measurements and electrochemical impedance spectroscopy (EIS). The films annealed at 550 °C exhibited a couple of redox peaks at 3.45 V vs. Li/Li+ characteristic for the electrochemical lithium insertion/extraction in LiFePO4. At low current rate such composite thin film showed a discharge capacity of over 110 mAh g-1. The dependence of charge transfer resistance, double layer capacitance and lithium diffusion coefficients on applied electrode potential were calculated from EIS data. Determined values of lithium diffusion coefficient were in the range from 8.3·10-13 cm2 s-1 to 1.2·10-13 cm2 s-1 at 3.4 V and 3.7 V, respectively. DEVELOPMENT OF COATINGS ON BLACK ENAMEL AND METHOD FOR DETERMINATION RADIATION ABSORPTION AND EMISSION CHARACTERISTICS J.Balodis, G.Bajars, J.Gabrusenoks, I.Liepiņa, A.Lūsis, G.Mežinskis * , * Institute of Silicate Materials, Riga Technical University Selective absorption of solar radiation in the development of coatings is used enamel on iron-chromium oxide pigment base. The spectral characterization of the enamel was applied to infrared and visible light spectroscopy. The resulting black enamel samples show good enough solar radiation absorption properties in the visible spectrum and near-infrared region (300-1000 nm). This reflected radiation is less than 10% of the incident energy. Infrared region will remain the same level of reflection. It's not good enough to create low-emission coating. Such spectral properties does not provide minimal thermal energy emission in the infrared region (
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Institute of Solid State Physics Un
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CONTENTS Introduction 4 Department
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ORGANIZATIONAL STUCTURE OF THE ISSP
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The annual report summarizes the re
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The main source for international f
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lector at the Faculty of Physics an
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the samples having different phase
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LABORATORY OF MAGNETIC RESONANCE SP
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Scientific publications 1. U. Rogul
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Main investigations and results ALU
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Lectures on Conferences 28 th LU Sc
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Main Results LASER CRYSTALLIZATION
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CONTROLLED MANIPULATION AND MECHANI
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DEPARTMENT OF FERROELECTRICS Head o
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Belorussia 1. Institute of solid st
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Density and dielectric properties f
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CONCENTRATION AND THERMAL PHASE TRA
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Latvia; SSPA ”Scientific-Practica
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• Δ T εmax : Mn>Co>Fe>Cu~Ni •
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Li x Na 1-x Ta y Nb 1-y O 3 Solid S
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34. А.И. Бурханов, И.Е.
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16. Š. Svirskas, M. Ivanov, Š. Ba
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45. С.Н. Каллаев, А.Р.
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LABORATORY OF VISUAL PERCEPTION Hea
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in terms of colour coordinate dispe
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4. R.Truksa, S.Fomins, M.Ozolins, "
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Scientific visits abroad 1. Dr. hab
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experimental data. We focused on th
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GB1 with oxygen vacancy revealed th
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Fig. 4. The thermodynamic stability
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a supercell model was used, and the
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a) b) l [110] d [110] (001) Fig. 9.
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Drain CNT Source Drain GNR Source 5
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The oxygen incorporation energy for
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such as high thermal stability, ver
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STATISTICAL ANALYSIS AND CELLULAR A
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REGIONS OF AZIMUTHAL INSTABILITY IN
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25. A. Gopejenko, Yu.F. Zhukovskii,
Page 77 and 78: 15. S. Piskunov and E. Spohr, "SrTi
Page 79 and 80: 43. P. Merzlakov, G. Zvejnieks, V.N
Page 81 and 82: XII. Annual Monitory Meeting of Eur
Page 83 and 84: 91. L. Shirmane, A.I. Popov, V. Pan
Page 85 and 86: 115. A.I. Popov, J. Zimmermann, V.
Page 87 and 88: Estonia Institute of Physics, Tartu
Page 89 and 90: 5. Grigorjeva L., Jankoviča D., Sm
Page 91 and 92: LABORATORY OF AMORPHOUS MATERIALS S
Page 93 and 94: Main results ABSORPTION AND LUMINES
Page 95 and 96: LUMINESCENCE OF FUSED AND UNFUSED B
Page 97 and 98: enables sensitive and selective det
Page 99 and 100: LABORATORY OF OPTICAL RECORDING Hea
Page 101 and 102: HOLOGRAPHIC LITHOGRAPHY IN AMORPHOU
Page 103 and 104: 5. U.Gertners, J.Teteris, The impac
Page 105 and 106: 24. J.Aleksejeva, J.Teteris, A.Tokm
Page 107 and 108: Israel Technion, Haifa (Dr.S.Stolya
Page 109 and 110: 3. A. Rusakova, J. Maniks, K. Schwa
Page 111 and 112: • Investigation of energetic stru
Page 113 and 114: Scheme 2 Synthesis of indane-1,3-di
Page 115 and 116: The synthesized compounds ZWK-1, DW
Page 117 and 118: 7. A. Vembris, K. Pudzs, I. Muzikan
Page 119 and 120: 20. A. Vembris, K. Pudzs, I. Muzika
Page 121 and 122: • Ion transfer problems related t
Page 123 and 124: 13. SIA „EMU PRIM”, 14. JSC „
Page 125 and 126: Main results Laboratory of Solid St
Page 127: Flax and Hemp Fiber Functionalizati
Page 131 and 132: Fig.1. Upper panel: 4 × 4 ×4 supe
Page 133 and 134: Fig.1. Left panel: Schematic view o
Page 135 and 136: Titania with anatase structure is i
Page 137 and 138: RESEARCH OF CATHODE MATERIALS FOR L
Page 139 and 140: 17. T Dizhbite, J Ponomarenko, A An
Page 141 and 142: 6. J. Kleperis, B. Sloka, J. Dimant
Page 143 and 144: 33. P. Lesnicenoks, A. Sivars, L. G
Page 145 and 146: France 1. Institute Laue-Langevin,
Page 147 and 148: different neutron orbits (11/2[615]
Page 149 and 150: LABORATORY OF ELECTRONIC ENGINEERIN
Page 151 and 152: 2. For JSC Augstsprieguma tīkls an
Page 153 and 154: 4. By orders of several organizatio
Page 155: Partners: Fonons Ltd, Riga Technica
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Annual Report 2012 - Latvijas Universitātes Cietvielu fizikas institūts

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