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G. S. Sarkisov - One of the best experts on this subject based on the ideXlab platform.
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Interferometric measurements of static and dynamic dipole polarizability of titanium atoms using fast electrical explosion of fine metal wires in vacuum
Physics of Plasmas, 2019Co-Authors: G. S. Sarkisov, Andrew Hamilton, V. I. SotnikovAbstract:The rapid electrical explosion of fine metal wires in vacuum generates gas cylinders of metal atoms surrounded by low-density and fast-expanding plasma corona. For fully vaporized wires, we utilize the integrated-phase technique, based on laser interferometry, to measure the dynamic dipole polarizability of metal atoms. Titanium wire with a diameter of 20 μm and a length of 1 cm was rapidly vaporized by a fast-rising current at ∼10 ns. We find that the dynamic dipole polarizability of titanium atoms equals 20.5 ± 2 A3 for 532 nm and 10.6 ± 1 A3 for 1064 nm. The wire reaches a totally vaporized state when the expansion velocity in a vacuum is ∼5.5 km/s. To vaporize Ti wire, the deposited Joule energy exceeded tabulated Enthalpy of Atomization by ∼2.8 times. Two-wavelength diagnostic allows reconstruction of the static dipole polarizability 9.13 ± 1.7 A3 and electron transition energy 3.13 ± 0.2 eV with the corresponding transition wavelength of 396.6 ± 26 nm. This reconstructed wavelength matches to the group of strong dipole-allowed atomic spectral lines for Ti between 394.87 and 402.46 nm for ground-state transitions 3d24s2.The rapid electrical explosion of fine metal wires in vacuum generates gas cylinders of metal atoms surrounded by low-density and fast-expanding plasma corona. For fully vaporized wires, we utilize the integrated-phase technique, based on laser interferometry, to measure the dynamic dipole polarizability of metal atoms. Titanium wire with a diameter of 20 μm and a length of 1 cm was rapidly vaporized by a fast-rising current at ∼10 ns. We find that the dynamic dipole polarizability of titanium atoms equals 20.5 ± 2 A3 for 532 nm and 10.6 ± 1 A3 for 1064 nm. The wire reaches a totally vaporized state when the expansion velocity in a vacuum is ∼5.5 km/s. To vaporize Ti wire, the deposited Joule energy exceeded tabulated Enthalpy of Atomization by ∼2.8 times. Two-wavelength diagnostic allows reconstruction of the static dipole polarizability 9.13 ± 1.7 A3 and electron transition energy 3.13 ± 0.2 eV with the corresponding transition wavelength of 396.6 ± 26 nm. This reconstructed wavelength matches to the gr...
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Vaporization energy and expansion velocity of electrically exploding aluminum and copper fine wires in vacuum
Journal of Applied Physics, 2018Co-Authors: Andrew Hamilton, V. I. Sotnikov, G. S. SarkisovAbstract:It has been experimentally shown that the complete vaporization of Al and Cu fine wires due to a fast electrical explosion in vacuum requires 2-3 times the standard Atomization Enthalpy of ∼4 eV/atom. The expansion speed of a fully evaporated Al wire in vacuum is ∼10 km/s and ∼8 km/s for Cu wire. This excess of evaporation energy over tabulated Enthalpy of Atomization is related to the “pressure cooker effect,” when a fine metal wire is heated by a fast-rising current with high magnetic and hydrodynamic pressures. In our paper, we demonstrate self-consistent relationships between the deposited energy, expansion rate, and state of the wire core for Al and Cu fine wires.
M. Fátima M. Piedade - One of the best experts on this subject based on the ideXlab platform.
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Thermochemistry of 1,1,3,3-tetramethylguanidine and 1,1,3,3-tetramethylguanidinium nitrate
The Journal of Chemical Thermodynamics, 2014Co-Authors: Joana Vitorino, Filipe Agapito, M. Fátima M. Piedade, Carlos E. S. Bernardes, Hermínio P. Diogo, João Paulo LealAbstract:Abstract Considerable efforts have recently been made to investigate how the structure of protic ionic liquids determines some of their most important properties for technological applications (e.g. low vapour pressure, conductivity). In contrast, the assessment of cohesive energies (which are also linked to those properties) based on thermodynamic results is still practically unexplored. This problem is addressed here for 1,1,3,3-tetramethylguanidinium nitrate, [ Htmg ] [ NO 3 ] , through a combination of experimental and computational chemistry results at the reference temperature of 298.15 K. The standard molar enthalpies of formation, Δ f H m o ( [ Htmg ] [ NO 3 ] ,cr ) = - ( 311.8 ± 2.3 ) kJ · mol - 1 , and fusion, Δ fus H m o ( [ Htmg ] [ NO 3 ] ) = 16.2 ± 3.8 kJ · mol - 1 , of solid 1,1,3,3-tetramethylguanidinium nitrate (form I polymorph) were obtained by combustion and differential scanning calorimetry, respectively. From these results Δ f H m o ( [ Htmg ] [ NO 3 ] ,l ) = - ( 295.6 ± 4.4 ) kJ · mol - 1 could be derived. Also determined were the standard molar enthalpies of formation, Δ f H m o ( tmg, l ) = 7.7 ± 2.8 kJ · mol - 1 , and vaporisation, Δ vap H m o ( tmg,l ) = 50.0 ± 1.2 kJ · mol - 1 , of 1,1,3,3-tetramethylguanidine, by reaction solution and Calvet-drop microcalorimetry, respectively, leading to Δ f H m o ( tmg,g ) = 57.7 ± 3.0 kJ · mol - 1 . This result is in excellent agreement with Δ f H m o ( tmg,g ) = 58.4 ± 4.0 kJ · mol - 1 , obtained from the ab initio calculation of the standard molar Enthalpy of Atomization of tmg using the W1-F12 procedure. From the above results, the cohesive energy of [ Htmg ] [ NO 3 ] (l) could be evaluated. Finally, the nature of a solid to solid phase transition observed for [ Htmg ] [ NO 3 ] at 221.4 ± 1.2 K using DSC was investigated by single crystal X-ray diffraction. The structural results indicate that complete proton transfer from HNO 3 to tmg only occurs above the phase transition temperature.
V. I. Sotnikov - One of the best experts on this subject based on the ideXlab platform.
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Interferometric measurements of static and dynamic dipole polarizability of titanium atoms using fast electrical explosion of fine metal wires in vacuum
Physics of Plasmas, 2019Co-Authors: G. S. Sarkisov, Andrew Hamilton, V. I. SotnikovAbstract:The rapid electrical explosion of fine metal wires in vacuum generates gas cylinders of metal atoms surrounded by low-density and fast-expanding plasma corona. For fully vaporized wires, we utilize the integrated-phase technique, based on laser interferometry, to measure the dynamic dipole polarizability of metal atoms. Titanium wire with a diameter of 20 μm and a length of 1 cm was rapidly vaporized by a fast-rising current at ∼10 ns. We find that the dynamic dipole polarizability of titanium atoms equals 20.5 ± 2 A3 for 532 nm and 10.6 ± 1 A3 for 1064 nm. The wire reaches a totally vaporized state when the expansion velocity in a vacuum is ∼5.5 km/s. To vaporize Ti wire, the deposited Joule energy exceeded tabulated Enthalpy of Atomization by ∼2.8 times. Two-wavelength diagnostic allows reconstruction of the static dipole polarizability 9.13 ± 1.7 A3 and electron transition energy 3.13 ± 0.2 eV with the corresponding transition wavelength of 396.6 ± 26 nm. This reconstructed wavelength matches to the group of strong dipole-allowed atomic spectral lines for Ti between 394.87 and 402.46 nm for ground-state transitions 3d24s2.The rapid electrical explosion of fine metal wires in vacuum generates gas cylinders of metal atoms surrounded by low-density and fast-expanding plasma corona. For fully vaporized wires, we utilize the integrated-phase technique, based on laser interferometry, to measure the dynamic dipole polarizability of metal atoms. Titanium wire with a diameter of 20 μm and a length of 1 cm was rapidly vaporized by a fast-rising current at ∼10 ns. We find that the dynamic dipole polarizability of titanium atoms equals 20.5 ± 2 A3 for 532 nm and 10.6 ± 1 A3 for 1064 nm. The wire reaches a totally vaporized state when the expansion velocity in a vacuum is ∼5.5 km/s. To vaporize Ti wire, the deposited Joule energy exceeded tabulated Enthalpy of Atomization by ∼2.8 times. Two-wavelength diagnostic allows reconstruction of the static dipole polarizability 9.13 ± 1.7 A3 and electron transition energy 3.13 ± 0.2 eV with the corresponding transition wavelength of 396.6 ± 26 nm. This reconstructed wavelength matches to the gr...
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Vaporization energy and expansion velocity of electrically exploding aluminum and copper fine wires in vacuum
Journal of Applied Physics, 2018Co-Authors: Andrew Hamilton, V. I. Sotnikov, G. S. SarkisovAbstract:It has been experimentally shown that the complete vaporization of Al and Cu fine wires due to a fast electrical explosion in vacuum requires 2-3 times the standard Atomization Enthalpy of ∼4 eV/atom. The expansion speed of a fully evaporated Al wire in vacuum is ∼10 km/s and ∼8 km/s for Cu wire. This excess of evaporation energy over tabulated Enthalpy of Atomization is related to the “pressure cooker effect,” when a fine metal wire is heated by a fast-rising current with high magnetic and hydrodynamic pressures. In our paper, we demonstrate self-consistent relationships between the deposited energy, expansion rate, and state of the wire core for Al and Cu fine wires.
Andrew Hamilton - One of the best experts on this subject based on the ideXlab platform.
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Interferometric measurements of static and dynamic dipole polarizability of titanium atoms using fast electrical explosion of fine metal wires in vacuum
Physics of Plasmas, 2019Co-Authors: G. S. Sarkisov, Andrew Hamilton, V. I. SotnikovAbstract:The rapid electrical explosion of fine metal wires in vacuum generates gas cylinders of metal atoms surrounded by low-density and fast-expanding plasma corona. For fully vaporized wires, we utilize the integrated-phase technique, based on laser interferometry, to measure the dynamic dipole polarizability of metal atoms. Titanium wire with a diameter of 20 μm and a length of 1 cm was rapidly vaporized by a fast-rising current at ∼10 ns. We find that the dynamic dipole polarizability of titanium atoms equals 20.5 ± 2 A3 for 532 nm and 10.6 ± 1 A3 for 1064 nm. The wire reaches a totally vaporized state when the expansion velocity in a vacuum is ∼5.5 km/s. To vaporize Ti wire, the deposited Joule energy exceeded tabulated Enthalpy of Atomization by ∼2.8 times. Two-wavelength diagnostic allows reconstruction of the static dipole polarizability 9.13 ± 1.7 A3 and electron transition energy 3.13 ± 0.2 eV with the corresponding transition wavelength of 396.6 ± 26 nm. This reconstructed wavelength matches to the group of strong dipole-allowed atomic spectral lines for Ti between 394.87 and 402.46 nm for ground-state transitions 3d24s2.The rapid electrical explosion of fine metal wires in vacuum generates gas cylinders of metal atoms surrounded by low-density and fast-expanding plasma corona. For fully vaporized wires, we utilize the integrated-phase technique, based on laser interferometry, to measure the dynamic dipole polarizability of metal atoms. Titanium wire with a diameter of 20 μm and a length of 1 cm was rapidly vaporized by a fast-rising current at ∼10 ns. We find that the dynamic dipole polarizability of titanium atoms equals 20.5 ± 2 A3 for 532 nm and 10.6 ± 1 A3 for 1064 nm. The wire reaches a totally vaporized state when the expansion velocity in a vacuum is ∼5.5 km/s. To vaporize Ti wire, the deposited Joule energy exceeded tabulated Enthalpy of Atomization by ∼2.8 times. Two-wavelength diagnostic allows reconstruction of the static dipole polarizability 9.13 ± 1.7 A3 and electron transition energy 3.13 ± 0.2 eV with the corresponding transition wavelength of 396.6 ± 26 nm. This reconstructed wavelength matches to the gr...
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Vaporization energy and expansion velocity of electrically exploding aluminum and copper fine wires in vacuum
Journal of Applied Physics, 2018Co-Authors: Andrew Hamilton, V. I. Sotnikov, G. S. SarkisovAbstract:It has been experimentally shown that the complete vaporization of Al and Cu fine wires due to a fast electrical explosion in vacuum requires 2-3 times the standard Atomization Enthalpy of ∼4 eV/atom. The expansion speed of a fully evaporated Al wire in vacuum is ∼10 km/s and ∼8 km/s for Cu wire. This excess of evaporation energy over tabulated Enthalpy of Atomization is related to the “pressure cooker effect,” when a fine metal wire is heated by a fast-rising current with high magnetic and hydrodynamic pressures. In our paper, we demonstrate self-consistent relationships between the deposited energy, expansion rate, and state of the wire core for Al and Cu fine wires.
O.e. Hankins - One of the best experts on this subject based on the ideXlab platform.
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Multiband analysis of photoluminescence spectra from electronically excited gas-phase species produced during laser ablation of lead oxide, zirconium oxide, titanium oxide, and lead zirconate titanate targets
Chemistry of Materials, 1995Co-Authors: N. R. Barnes, R. Dat, Daniel J. Lichtenwalner, A. F. Schreiner, O. Auciello, O.e. HankinsAbstract:The analysis of multiband/line photoluminescence spectra produced by electronically excited gas-phase species in the plasma plume, generated by impact of a KrF excimer laser beam (248 nm) on various metal oxide targets, has been carried out, and the results are reported. It was established that, at 1.1 J/cm{sup 2} in 900 mTorr of O{sub 2}, (i) Pb(I), Pb(II), and O{sub 2}{sup +} are generated from PbO(s) targets; (ii) Zr(I), Zr(II), ZrO, O{sub 2}, and O{sub 2}{sup +} from ZrO{sub 2}(s) targets; (iii) Ti(I), Ti(II), TiO, TiO{sub 2}, and O{sub 2}{sup +} from TiO{sub 2}(s) targets; and (iv) Pb(I), Pb(II), PbO, Zr(I), Zr(II), ZrO, Ti(I), Ti(II), TiO, TiO{sub 2}, O(I), O(II), O{sub 2}, and O{sub 2}{sup +} from a solid Pb(Zr{sub x}Ti{sub 1-x})O{sub 3}(PZT) target. The observation of excited oxygen species may be attributed to the presence of ambient molecular O{sub 2} and/or the oxygen-rich metal oxide and PZT targets. The much lower standard Enthalpy of Atomization, {Delta}H{sub a}{sup 0}, for PbO(s) and the much higher {Delta}H{sub a}{sup 0} values for ZrO{sub 2}(s) and TiO{sub 2}(s) are consistent with observing molecular metal oxide species, MO{sub n}(g), in the ablation plume from ZrO{sub 2}(s) and TiO{sub 2}(s) but observing almost exclusively atomicmore » Pb(I) and Pb(II) from the PbO(s) target. Additionally, a detailed explanation regarding the observation of lower-charged atomic metal species and not the higher-charged (formally ionic) species is presented. Particle ejection is briefly discussed as also is the relative influence of the observed species on thin-film deposition. 30 refs., 4 figs., 8 tabs.« less