The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Youngjong Kang - One of the best experts on this subject based on the ideXlab platform.
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Fabrication of the tetrathiafulvalene–2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane charge transfer complex with high crystallinity by Eutectic Melting method
Japanese Journal of Applied Physics, 2018Co-Authors: Youngjong KangAbstract:We show that high crystallinity and charge transporting gain can be obtained in a noble donor–acceptor system (CT complex) composed of organic complex: tetrathiafulvalene–2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (TTF–F4TCNQ). The complex is small-gap organic metallic or semiconductor (less than 1 eV), and we predict having a high conductivity. We perform an approach to fabricate organic CT complex with high crystallinity by Eutectic Melting method. Our process is simple and shows crystal growth with improved crystallinity when combined with soft-lithography.
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fabrication of the tetrathiafulvalene 2 3 5 6 tetrafluoro 7 7 8 8 tetracyanoquinodimethane charge transfer complex with high crystallinity by Eutectic Melting method
Japanese Journal of Applied Physics, 2018Co-Authors: Youngjong KangAbstract:We show that high crystallinity and charge transporting gain can be obtained in a noble donor–acceptor system (CT complex) composed of organic complex: tetrathiafulvalene–2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (TTF–F4TCNQ). The complex is small-gap organic metallic or semiconductor (less than 1 eV), and we predict having a high conductivity. We perform an approach to fabricate organic CT complex with high crystallinity by Eutectic Melting method. Our process is simple and shows crystal growth with improved crystallinity when combined with soft-lithography.
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alq3 nanorod arrays by temperature gradient assisted Eutectic Melting and crystallization
Materials Letters, 2014Co-Authors: Jeyon Chung, Jinho Hyon, Taehoon Kwon, Youngjong KangAbstract:Abstract The mixtures of Alq 3 and naphthalene have been used for creating single-crystalline Alq 3 nanorod arrays by temperature-gradient-assisted Melting/crystallization method. Due to the formation of Eutectic mixtures, the Alq 3 and naphthalene mixtures can be melted and crystallized at low temperature ( 3 nanorods were isolated after removing naphthalene by sublimation. XRD and SAED of Alq 3 nanorods showed that they are α-phase single-crystalline Alq 3 . Alq 3 nanorod arrays were spontaneously formed without lithographic process when the temperature gradient was applied to the samples upon cooling. All Alq 3 nanorods were aligned along the direction of the temperature gradient.
Torben R Jensen - One of the best experts on this subject based on the ideXlab platform.
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Effect of Eutectic Melting, Reactive Hydride Composites, and Nanoconfinement on Decomposition and Reversibility of LiBH4–KBH4
Journal of Physical Chemistry C, 2015Co-Authors: Elsa Roedern, Bjarne R S Hansen, Torben R JensenAbstract:Eutectic Melting, reactive hydride composites, and nanoconfinement have the potential to improve the reversible hydrogen storage properties in metal borohydrides. We study and compare the combined effect of all three methods on reversible hydrogen release and uptake of the Eutectic Melting lithium potassium borohydride system, 0.725LiBH4–0.275KBH4, with low Melting temperature (Tm = 105 °C). The Eutectic mixture and reactive hydride composites of the Eutectic mixture with Mg or MgH2 are melt infiltrated into a CO2 activated nanoporous carbon scaffold, and their properties are compared to those of bulk samples. The decomposition of 0.725LiBH4–0.275KBH4 and the reactive hydride composites initiates simultaneously with the Melting at 105 °C, but the decomposition remains slow until higher temperatures are reached (T > 300 °C). Eutectic Melting appears to improve kinetics of hydrogen release and absorption, while nanoconfinement lowers the main hydrogen release temperature in the first cycle by up to 200 °C. ...
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effect of Eutectic Melting reactive hydride composites and nanoconfinement on decomposition and reversibility of libh4 kbh4
Journal of Physical Chemistry C, 2015Co-Authors: Elsa Roedern, Bjarne R S Hansen, Torben R JensenAbstract:Eutectic Melting, reactive hydride composites, and nanoconfinement have the potential to improve the reversible hydrogen storage properties in metal borohydrides. We study and compare the combined effect of all three methods on reversible hydrogen release and uptake of the Eutectic Melting lithium potassium borohydride system, 0.725LiBH4–0.275KBH4, with low Melting temperature (Tm = 105 °C). The Eutectic mixture and reactive hydride composites of the Eutectic mixture with Mg or MgH2 are melt infiltrated into a CO2 activated nanoporous carbon scaffold, and their properties are compared to those of bulk samples. The decomposition of 0.725LiBH4–0.275KBH4 and the reactive hydride composites initiates simultaneously with the Melting at 105 °C, but the decomposition remains slow until higher temperatures are reached (T > 300 °C). Eutectic Melting appears to improve kinetics of hydrogen release and absorption, while nanoconfinement lowers the main hydrogen release temperature in the first cycle by up to 200 °C. ...
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Melting Behavior and Thermolysis of NaBH 4 −Mg(BH 4 ) 2 and NaBH 4 −Ca(BH 4 ) 2 Composites
Energies, 2015Co-Authors: Elsa Roedern, Peter Thygesen, Torben R JensenAbstract:The physical properties and the hydrogen release of NaBH 4 –Mg(BH 4 ) 2 and NaBH 4 −Ca(BH 4 ) 2 composites are investigated using in situ synchrotron radiation powder X-ray diffraction, thermal analysis and temperature programmed photographic analysis. The composite, x NaBH 4 –(1 − x )Mg(BH 4 ) 2 , x = 0.4 to 0.5, shows Melting/frothing between 205 and 220 °C. However, the sample does not become a transparent molten phase. This behavior is similar to other alkali-alkaline earth metal borohydride composites. In the x NaBH 4 –(1 − x )Ca(BH 4 ) 2 system, Eutectic Melting is not observed. Interestingly, Eutectic Melting in metal borohydrides systems leads to partial thermolysis and hydrogen release at lower temperatures and the control of sample Melting may open new routes for obtaining high-capacity hydrogen storage materials.
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Eutectic Melting of libh4 kbh4
Physical Chemistry Chemical Physics, 2014Co-Authors: Elsa Roedern, Torben R JensenAbstract:Eutectic Melting in mixtures of alkali and alkali earth metal borohydrides can pave the way for new applications as fast ionic conductors, and facilitate hydrogen release by low temperature chemical reactions and convenient nanoconfinement. Here, we determine the Eutectic composition for the lithium potassium borohydride system, 0.725LiBH4–0.275KBH4, with the lowest Melting point, Tmelt ∼105 °C, of all known alkali and alkali earth metal borohydride mixtures. Mechanochemistry and manual mixing of LiBH4–KBH4 mixtures facilitate the formation of LiK(BH4)2. However, the Melting or heat treatments used in this work do not produce LiK(BH4)2. The bimetallic borohydride dissociates into the monometallic borohydrides at ∼95 °C and partial Melting occurs at ∼105 °C. Analysis of the unit cell volumes of LiBH4, KBH4 and LiK(BH4)2 in the temperature range 25 to 90 °C indicates that the formation of the bimetallic borohydride is facilitated by a more dense packing as compared to the reactants. Thus, LiK(BH4)2 is considered metastable and the formation is pressure induced. A phase diagram for the LiBH4–KBH4 system is established, which illustrates the low Eutectic Melting point and the stability range for the bimetallic borohydride, LiK(BH4)2.
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Eutectic Melting in metal borohydrides
Physical Chemistry Chemical Physics, 2013Co-Authors: Mark Paskevicius, Torben R Jensen, Drew A Sheppard, Craig E BuckleyAbstract:A series of monometallic borohydrides and borohydride Eutectic mixtures have been investigated during thermal ramping by mass spectroscopy, differential scanning calorimetry, and photography. Mixtures of LiBH4–NaBH4, LiBH4–KBH4, LiBH4–Mg(BH4)2, LiBH4–Ca(BH4)2, LiBH4–Mn(BH4)2, NaBH4–KBH4, and LiBH4–NaBH4–KBH4 all displayed Melting behaviour below that of the monometallic phases (up to 167 °C lower). Generally, each system behaves differently with respect to their physical behaviour upon Melting. The molten phases can exhibit colour changes, bubbling and in some cases frothing, or even liquid–solid phase transitions during hydrogen release. Remarkably, the Eutectic melt can also allow for hydrogen release at temperatures lower than that of the individual components. Some systems display decomposition of the borohydride in the solid-state before Melting and certain hydrogen release events have also been linked to the adverse reaction of samples with impurities, usually within the starting reagents, and these may also be coupled with bubbling or frothing of the ionic melt.
Elsa Roedern - One of the best experts on this subject based on the ideXlab platform.
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Effect of Eutectic Melting, Reactive Hydride Composites, and Nanoconfinement on Decomposition and Reversibility of LiBH4–KBH4
Journal of Physical Chemistry C, 2015Co-Authors: Elsa Roedern, Bjarne R S Hansen, Torben R JensenAbstract:Eutectic Melting, reactive hydride composites, and nanoconfinement have the potential to improve the reversible hydrogen storage properties in metal borohydrides. We study and compare the combined effect of all three methods on reversible hydrogen release and uptake of the Eutectic Melting lithium potassium borohydride system, 0.725LiBH4–0.275KBH4, with low Melting temperature (Tm = 105 °C). The Eutectic mixture and reactive hydride composites of the Eutectic mixture with Mg or MgH2 are melt infiltrated into a CO2 activated nanoporous carbon scaffold, and their properties are compared to those of bulk samples. The decomposition of 0.725LiBH4–0.275KBH4 and the reactive hydride composites initiates simultaneously with the Melting at 105 °C, but the decomposition remains slow until higher temperatures are reached (T > 300 °C). Eutectic Melting appears to improve kinetics of hydrogen release and absorption, while nanoconfinement lowers the main hydrogen release temperature in the first cycle by up to 200 °C. ...
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effect of Eutectic Melting reactive hydride composites and nanoconfinement on decomposition and reversibility of libh4 kbh4
Journal of Physical Chemistry C, 2015Co-Authors: Elsa Roedern, Bjarne R S Hansen, Torben R JensenAbstract:Eutectic Melting, reactive hydride composites, and nanoconfinement have the potential to improve the reversible hydrogen storage properties in metal borohydrides. We study and compare the combined effect of all three methods on reversible hydrogen release and uptake of the Eutectic Melting lithium potassium borohydride system, 0.725LiBH4–0.275KBH4, with low Melting temperature (Tm = 105 °C). The Eutectic mixture and reactive hydride composites of the Eutectic mixture with Mg or MgH2 are melt infiltrated into a CO2 activated nanoporous carbon scaffold, and their properties are compared to those of bulk samples. The decomposition of 0.725LiBH4–0.275KBH4 and the reactive hydride composites initiates simultaneously with the Melting at 105 °C, but the decomposition remains slow until higher temperatures are reached (T > 300 °C). Eutectic Melting appears to improve kinetics of hydrogen release and absorption, while nanoconfinement lowers the main hydrogen release temperature in the first cycle by up to 200 °C. ...
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Melting Behavior and Thermolysis of NaBH4−Mg(BH4)2 and NaBH4−Ca(BH4)2 Composites
Energies, 2015Co-Authors: Elsa Roedern, Peter Thygesen, Torben JensenAbstract:The physical properties and the hydrogen release of NaBH4–Mg(BH4)2 and NaBH4−Ca(BH4)2 composites are investigated using in situ synchrotron radiation powder X-ray diffraction, thermal analysis and temperature programmed photographic analysis. The composite, xNaBH4–(1 − x)Mg(BH4)2, x = 0.4 to 0.5, shows Melting/frothing between 205 and 220 °C. However, the sample does not become a transparent molten phase. This behavior is similar to other alkali-alkaline earth metal borohydride composites. In the xNaBH4–(1 − x)Ca(BH4)2 system, Eutectic Melting is not observed. Interestingly, Eutectic Melting in metal borohydrides systems leads to partial thermolysis and hydrogen release at lower temperatures and the control of sample Melting may open new routes for obtaining high-capacity hydrogen storage materials
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Melting Behavior and Thermolysis of NaBH 4 −Mg(BH 4 ) 2 and NaBH 4 −Ca(BH 4 ) 2 Composites
Energies, 2015Co-Authors: Elsa Roedern, Peter Thygesen, Torben R JensenAbstract:The physical properties and the hydrogen release of NaBH 4 –Mg(BH 4 ) 2 and NaBH 4 −Ca(BH 4 ) 2 composites are investigated using in situ synchrotron radiation powder X-ray diffraction, thermal analysis and temperature programmed photographic analysis. The composite, x NaBH 4 –(1 − x )Mg(BH 4 ) 2 , x = 0.4 to 0.5, shows Melting/frothing between 205 and 220 °C. However, the sample does not become a transparent molten phase. This behavior is similar to other alkali-alkaline earth metal borohydride composites. In the x NaBH 4 –(1 − x )Ca(BH 4 ) 2 system, Eutectic Melting is not observed. Interestingly, Eutectic Melting in metal borohydrides systems leads to partial thermolysis and hydrogen release at lower temperatures and the control of sample Melting may open new routes for obtaining high-capacity hydrogen storage materials.
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Eutectic Melting of libh4 kbh4
Physical Chemistry Chemical Physics, 2014Co-Authors: Elsa Roedern, Torben R JensenAbstract:Eutectic Melting in mixtures of alkali and alkali earth metal borohydrides can pave the way for new applications as fast ionic conductors, and facilitate hydrogen release by low temperature chemical reactions and convenient nanoconfinement. Here, we determine the Eutectic composition for the lithium potassium borohydride system, 0.725LiBH4–0.275KBH4, with the lowest Melting point, Tmelt ∼105 °C, of all known alkali and alkali earth metal borohydride mixtures. Mechanochemistry and manual mixing of LiBH4–KBH4 mixtures facilitate the formation of LiK(BH4)2. However, the Melting or heat treatments used in this work do not produce LiK(BH4)2. The bimetallic borohydride dissociates into the monometallic borohydrides at ∼95 °C and partial Melting occurs at ∼105 °C. Analysis of the unit cell volumes of LiBH4, KBH4 and LiK(BH4)2 in the temperature range 25 to 90 °C indicates that the formation of the bimetallic borohydride is facilitated by a more dense packing as compared to the reactants. Thus, LiK(BH4)2 is considered metastable and the formation is pressure induced. A phase diagram for the LiBH4–KBH4 system is established, which illustrates the low Eutectic Melting point and the stability range for the bimetallic borohydride, LiK(BH4)2.
Necmettin Maraşlı - One of the best experts on this subject based on the ideXlab platform.
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Experimental measurements of some thermophysical properties of solid CdSb intermetallic in the Sn–Cd–Sb ternary alloy
Journal of Thermal Analysis and Calorimetry, 2016Co-Authors: Esra Öztürk, K. Keşlioğlu, Sezen Aksöz, Yemliha Altıntas, Necmettin MaraşlıAbstract:The equilibrated grain boundary groove shapes of solid CdSb in equilibrium with Sn–Cd–Sb Eutectic liquid were observed from a quenched sample by using a radial heat flow apparatus. The Gibbs–Thomson coefficient, solid–liquid interfacial energy and grain boundary energy of the solid CdSb intermetallic were determined from the observed grain boundary groove shapes. The thermal conductivity of the Eutectic solid and the thermal conductivity ratio of Eutectic liquid to the Eutectic solid in the Sn–35.8 at.%Cd–6.71 at.%Sb Eutectic alloy at its Eutectic Melting temperature were also measured with a radial heat flow apparatus and a Bridgman-type growth apparatus, respectively.
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measurement of solid liquid interfacial energy in the in bi Eutectic alloy at low Melting temperature
Journal of Physics: Condensed Matter, 2007Co-Authors: Necmettin Maraşlı, Y. Ocak, S. Akbulut, U. Böyük, K. Keşlioğlu, Hasan Kaya, Emin CadirliAbstract:The Gibbs‐Thomson coefficient and solid‐liquid interfacial energy of the solid In solution in equilibrium with In Bi Eutectic liquid have been determined to be (1.46 ± 0.07) × 10 −7 Kma nd(40.4 ± 4.0) × 10 −3 Jm −2 by observing the equilibrated grain boundary groove shapes. The grain boundary energy of the solid In solution phase has been calculated to be (79.0 ± 8.7) × 10 −3 Jm −2 by considering force balance at the grain boundary grooves. The thermal conductivities of the In‐12.4 at.% Bi Eutectic liquid phase and the solid In solution phase and their ratio at the Eutectic Melting temperature (72 ◦ C) have also been measured with radial heat flow apparatus and Bridgman-type growth apparatus.
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Measurement of solid–liquid interfacial energy for solid d-camphor solution in equilibrium with succinonitrile d-camphor Eutectic liquid
Scripta Materialia, 2006Co-Authors: Y. Ocak, S. Akbulut, U. Böyük, M. Erol, K. Keşlioğlu, Necmettin MaraşlıAbstract:The Gibbs–Thomson coefficient, solid–liquid interfacial energy and grain boundary energy of solid d -camphor solution in equilibrium with succinonitrile d -camphor Eutectic liquid have been determined from the observed grain boundary groove shapes. Thermal conductivities of Eutectic solid and Eutectic liquid at the Eutectic Melting temperature have also been measured.
Lawrence P. Cook - One of the best experts on this subject based on the ideXlab platform.
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DTA/TGA Study of Eutectic Melting in the System BaF2-BaO-Y2O3-CuOx-H2O | NIST
MRS Proceedings, 2020Co-Authors: Lawrence P. Cook, Winnie Wong-ngAbstract:ABSTRACTDifferential thermal analysis and thermogravimetric analysis (DTA/TGA) experiments have been completed in the BaF2-BaO-Y2O3-CuOx-H2O system at various oxygen pressures to determine the effect of adding solid BaF2and gaseous H2O (at pH2O = 2.5 kPa) on the Eutectic Melting in the system BaO-Y2O3-CuOx. We have investigated the Eutectic Melting temperature over the range of pO2 = 20 Pa to pO2 = 0.1 MPa under the following conditions: 1) without BaF2 or H2O; 2) with H2O only; 3) with BaF2 only; 4) with both BaF2 and H2O. Results indicate that without BaF2 or H2O, Eutectic Melting is depressed from 917°C at pO2 = 0.1 MPa to 838°C at pO2 = 1 kPa. At oxygen pressures below 1 kPa, down to pO2 = 20 Pa, no further lowering of Eutectic Melting temperature was observed. The topologies of the temperature vs. log pO2 curves for various combinations of BaF2 and H2O were similar to that for the experiments without BaF2 or H2O, but all curves were shifted to lower temperatures. For the experiments with addition of BaF2 only, H2O only, and BaF2 with H2O, the Eutectic Melting temperatures as a function of pO2 were lowered by, respectively, 5°C - 15°C, 15°C - 25°C and 20°C - 30°C. Application of results to the “BaF2ex-situ” method of processing Ba2YCu3Ox coated conductors is discussed.
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Subsolidus and Melting phase relationships of the PbOxCaOCuO system in air
Physica C-superconductivity and Its Applications, 1997Co-Authors: W. Wong-ng, Lawrence P. Cook, W. Greenwood, F. JiangAbstract:Abstract Phase equilibrium studies of the PbO x CaOCuO system were conducted from the subsolidus at 770°C to the Melting of Ca 2 CuO 3 at 1034°C. No ternary oxide compounds were found. Twelve isothermal sections and a liquidus diagram outlining the primary phase fields are presented. At 770°C, in the subsolidus, Ca 2 PbO 4 was found to be in equilibrium with Ca 2 CuO 3 , CaO, PbO x and CuO. The Eutectic Melting temperature is ≈ 780°C, and the Eutectic Melting reaction is: PbO + Ca 2 PbO 4 + CuO → liquid. Two additional ternary Melting reactions were characterized. Above 1034°C, the only solid compounds remaining are CaO and CuO.
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bao 1 2y2o3 cuox Eutectic Melting in air
Journal of the American Ceramic Society, 1994Co-Authors: Winnie Wongng, Lawrence P. CookAbstract:Eutectic Melting in the BaO-[1/2]Y[sub 2]O[sub 3]-CuO[sub x] system has been investigated, using three different compositions. Thermal events up to 1,100 C were studied by means of differential thermal analysis/thermogravimetric analysis (DTA/TGA). Phase formation and compositions of melts were examined using powder X-ray diffraction and scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM/EDS) of quenched experiments. The Eutectic occurs at 923 [+-] 10 C in CO[sub 2]-, and H[sub 2]O-scrubbed air, and the Eutectic melt has a Ba:Y:Cu cation ratio of 23.2([+-]0.5):0.5([+-]0.1):76.3(1.0). The oxygen content of the quenched Eutectic melt, as determined by hydrogen reduction, indicated that nearly all of the copper in the melt was present as Cu[sup +]. A topological sequence, based on the X-ray results, is presented which describes the events immediately following Melting.
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BaO–1/2Y2O3–CuOx Eutectic Melting in Air
Journal of the American Ceramic Society, 1994Co-Authors: Winnie Wong-ng, Lawrence P. CookAbstract:Eutectic Melting in the BaO-[1/2]Y[sub 2]O[sub 3]-CuO[sub x] system has been investigated, using three different compositions. Thermal events up to 1,100 C were studied by means of differential thermal analysis/thermogravimetric analysis (DTA/TGA). Phase formation and compositions of melts were examined using powder X-ray diffraction and scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM/EDS) of quenched experiments. The Eutectic occurs at 923 [+-] 10 C in CO[sub 2]-, and H[sub 2]O-scrubbed air, and the Eutectic melt has a Ba:Y:Cu cation ratio of 23.2([+-]0.5):0.5([+-]0.1):76.3(1.0). The oxygen content of the quenched Eutectic melt, as determined by hydrogen reduction, indicated that nearly all of the copper in the melt was present as Cu[sup +]. A topological sequence, based on the X-ray results, is presented which describes the events immediately following Melting.
