scholarly journals Interaction of Hydrogen with Actinide Dioxide (111) Surfaces

2019 ◽  
Author(s):  
James Pegg ◽  
Ashley E. Shields ◽  
Mark T. Storr ◽  
David Scanlon ◽  
Nora De Leeuw
Keyword(s):  
Charge Distribution ◽  
Atomic Hydrogen ◽  
Molecular Hydrogen ◽  
Hydrogen Adsorption ◽  
Hydroxyl Group ◽  
Spin Orbit ◽  
Hydrogen Ions ◽  
Cell Method ◽  
Spin Orbit Interactions ◽  
Thermodynamic Factors

The interaction of atomic and molecular hydrogen with the actinide dioxide (AnO<sub>2</sub>, An = U, Np, Pu) (111) surfaces has been investigated by DFT+U, where noncollinear 3k antiferromagnetic (AFM) behaviour and spin-orbit interactions (SOI) are considered. The adsorption of atomic hydrogen forms a hydroxide group, and is coupled to the reduction of an actinide ion. The energy of atomic hydrogen adsorption on the UO<sub>2</sub> (0.82 eV), NpO<sub>2</sub> (-0.10 eV), and PuO<sub>2</sub> (-1.25 eV) surfaces has been calculated. The dissociation of molecular hydrogen is not observed, and shown to be due to kinetic rather than thermodynamic factors. As a barrier in the formation of a second hydroxyl group, an unusual charge distribution has been shown. This is possibly a limitation of a (1·1) unit cell method. The recombination of hydrogen ions on the AnO<sub>2</sub> (111) surfaces is favoured over hydroxide formation.

scholarly journals The Interaction of Hydrogen with Actinide Dioxide (111) Surfaces

2019 ◽  
Author(s):  
James Pegg ◽  
Ashley E. Shields ◽  
Mark T. Storr ◽  
David Scanlon ◽  
Nora De Leeuw
Keyword(s):  
Charge Distribution ◽  
Atomic Hydrogen ◽  
Molecular Hydrogen ◽  
Hydrogen Adsorption ◽  
Hydroxyl Group ◽  
Spin Orbit ◽  
Hydrogen Ions ◽  
Cell Method ◽  
Spin Orbit Interactions ◽  
Thermodynamic Factors

The interaction of atomic and molecular hydrogen with the actinide dioxide (AnO<sub>2</sub>, An = U, Np, Pu) (111) surfaces has been investigated by DFT+U, where noncollinear 3k antiferromagnetic (AFM) behaviour and spin-orbit interactions (SOI) are considered. The adsorption of atomic hydrogen forms a hydroxide group, and is coupled to the reduction of an actinide ion. The energy of atomic hydrogen adsorption on the UO<sub>2</sub> (0.82 eV), NpO<sub>2</sub> (-0.10 eV), and PuO<sub>2</sub> (-1.25 eV) surfaces has been calculated. The dissociation of molecular hydrogen is not observed, and shown to be due to kinetic rather than thermodynamic factors. As a barrier in the formation of a second hydroxyl group, an unusual charge distribution has been shown. This is possibly a limitation of a (1·1) unit cell method. The recombination of hydrogen ions on the AnO<sub>2</sub> (111) surfaces is favoured over hydroxide formation.

scholarly journals Interaction of Hydrogen with Actinide Dioxide (111) Surfaces

2019 ◽  
Author(s):  
James Pegg ◽  
Ashley E. Shields ◽  
Mark T. Storr ◽  
David Scanlon ◽  
Nora De Leeuw
Keyword(s):  
Charge Distribution ◽  
Atomic Hydrogen ◽  
Molecular Hydrogen ◽  
Hydrogen Adsorption ◽  
Hydroxyl Group ◽  
Spin Orbit ◽  
Hydrogen Ions ◽  
Cell Method ◽  
Spin Orbit Interactions ◽  
Thermodynamic Factors

The interaction of atomic and molecular hydrogen with the actinide dioxide (AnO<sub>2</sub>, An = U, Np, Pu) (111) surfaces has been investigated by DFT+U, where noncollinear 3k antiferromagnetic (AFM) behaviour and spin-orbit interactions (SOI) are considered. The adsorption of atomic hydrogen forms a hydroxide group, and is coupled to the reduction of an actinide ion. The energy of atomic hydrogen adsorption on the UO<sub>2</sub> (0.82 eV), NpO<sub>2</sub> (-0.10 eV), and PuO<sub>2</sub> (-1.25 eV) surfaces has been calculated. The dissociation of molecular hydrogen is not observed, and shown to be due to kinetic rather than thermodynamic factors. As a barrier in the formation of a second hydroxyl group, an unusual charge distribution has been shown. This is possibly a limitation of a (1·1) unit cell method. The recombination of hydrogen ions on the AnO<sub>2</sub> (111) surfaces is favoured over hydroxide formation.

scholarly journals Interaction of Hydrogen with Actinide Dioxide (011) Surfaces

2020 ◽  
Author(s):  
James Pegg ◽  
Ashley E. Shields ◽  
Mark T. Storr ◽  
David Scanlon ◽  
Nora De Leeuw
Keyword(s):  
Atomic Hydrogen ◽  
Hydrogen Adsorption ◽  
Storage Management ◽  
Nuclear Materials ◽  
Spin Orbit ◽  
Hydrogen Ions ◽  
Subsequent Formation ◽  
Catalysed Oxidation ◽  
Fuel Storage ◽  
Spin Orbit Interactions

<p>The hydrogen catalysed oxidation of nuclear materials has led to containment vessel failure. The interaction of hydrogen with actinide dioxide (AnO<sub>2</sub>, An = U, Np, Pu) (011) surfaces has been completed by DFT+U; where, spin-orbit interactions and noncollinear 3k antiferromagnetic behaviour have been included. The energy of atomic hydrogen adsorption for UO<sub>2</sub> (0.44 eV), NpO<sub>2</sub> (-0.47 eV), and PuO<sub>2</sub> (-1.71 eV) has been calculated, where the subsequent formation of an OH group is shown to distort the surface structure. The dissociation of hydrogen on the PuO<sub>2</sub> (011) surfaces has been found; however, UO<sub>2</sub> (011) and NpO<sub>2</sub> (011) surfaces are relatively inert. The recombination of hydrogen ions on the UO<sub>2</sub> (011) and NpO<sub>2</sub> (011) surfaces is highly-probable; whereas, hydroxide formation on the PuO<sub>2</sub> (011) surface has been shown. The results have consequences for fuel storage management.</p>

scholarly journals Interaction of Hydrogen with Actinide Dioxide (011) Surfaces

2020 ◽  
Author(s):  
James Pegg ◽  
Ashley E. Shields ◽  
Mark T. Storr ◽  
David Scanlon ◽  
Nora De Leeuw
Keyword(s):  
Atomic Hydrogen ◽  
Hydrogen Adsorption ◽  
Storage Management ◽  
Nuclear Materials ◽  
Spin Orbit ◽  
Hydrogen Ions ◽  
Subsequent Formation ◽  
Catalysed Oxidation ◽  
Fuel Storage ◽  
Spin Orbit Interactions

<p>The hydrogen catalysed oxidation of nuclear materials has led to containment vessel failure. The interaction of hydrogen with actinide dioxide (AnO<sub>2</sub>, An = U, Np, Pu) (011) surfaces has been completed by DFT+U; where, spin-orbit interactions and noncollinear 3k antiferromagnetic behaviour have been included. The energy of atomic hydrogen adsorption for UO<sub>2</sub> (0.44 eV), NpO<sub>2</sub> (-0.47 eV), and PuO<sub>2</sub> (-1.71 eV) has been calculated, where the subsequent formation of an OH group is shown to distort the surface structure. The dissociation of hydrogen on the PuO<sub>2</sub> (011) surfaces has been found; however, UO<sub>2</sub> (011) and NpO<sub>2</sub> (011) surfaces are relatively inert. The recombination of hydrogen ions on the UO<sub>2</sub> (011) and NpO<sub>2</sub> (011) surfaces is highly-probable; whereas, hydroxide formation on the PuO<sub>2</sub> (011) surface has been shown. The results have consequences for fuel storage management.</p>

scholarly journals Interaction of Hydrogen with Actinide Dioxide (011) Surfaces

2019 ◽  
Author(s):  
James Pegg ◽  
Ashley E. Shields ◽  
Mark T. Storr ◽  
David Scanlon ◽  
Nora De Leeuw
Keyword(s):  
Atomic Hydrogen ◽  
Hydrogen Adsorption ◽  
Storage Management ◽  
Nuclear Materials ◽  
Spin Orbit ◽  
Hydrogen Ions ◽  
Subsequent Formation ◽  
Catalysed Oxidation ◽  
Fuel Storage ◽  
Spin Orbit Interactions

<p>The hydrogen catalysed oxidation of nuclear materials has led to containment vessel failure. The interaction of hydrogen with actinide dioxide (AnO<sub>2</sub>, An = U, Np, Pu) (011) surfaces has been completed by DFT+U; where, spin-orbit interactions and noncollinear 3k antiferromagnetic behaviour have been included. The energy of atomic hydrogen adsorption for UO<sub>2</sub> (0.44 eV), NpO<sub>2</sub> (-0.47 eV), and PuO<sub>2</sub> (-1.71 eV) has been calculated, where the subsequent formation of an OH group is shown to distort the surface structure. The dissociation of hydrogen on the PuO<sub>2</sub> (011) surfaces has been found; however, UO<sub>2</sub> (011) and NpO<sub>2</sub> (011) surfaces are relatively inert. The recombination of hydrogen ions on the UO<sub>2</sub> (011) and NpO<sub>2</sub> (011) surfaces is highly-probable; whereas, hydroxide formation on the PuO<sub>2</sub> (011) surface has been shown. The results have consequences for fuel storage management.</p>

Further investigations of charge exchange and electron detachment - I. Ion energies 3 to 40 keV - II. Ion energies 100 to 4000 eV

1955 ◽  
Vol 227 (1171) ◽  
pp. 466-486 ◽  
Keyword(s):  
Charge Transfer ◽  
Energy Range ◽  
Cross Sections ◽  
Atomic Hydrogen ◽  
Molecular Hydrogen ◽  
Hydrogen Ions ◽  
Electron Detachment ◽  
Rare Gases ◽  
Helium Ions ◽  
Ion Energies

This paper describes the measurement of charge transfer cross-sections for protons, molecular hydrogen ions and helium ions in the rare gases and hydrogen, and electron detachment cross-sections for negative atomic hydrogen ions in the rare gases. Part I describes the energy range 3 to 40 keV. In part II the energy range 100 to 4000 eV is described, and the results are discussed in terms of the pseudo-adiabatic hypothesis. Comparisons are made with other experimental results, and anomalous molecular cases are discussed in terms of reactions involving anti-bonding states.

scholarly journals FORMATION OF LIGHT IMPURITIES IN A HYDROGEN PLASMA AT INITIAL STAGE OF A DISCHARGE

2019 ◽  
pp. 110-112
Author(s):  
V.B. Yuferov ◽  
E.I. Skibenko ◽  
V.I. Tkachov ◽  
V.V. Katrechko ◽  
A.S. Svichkar
Keyword(s):  
Atomic Hydrogen ◽  
Molecular Hydrogen ◽  
Hydrogen Plasma ◽  
Hydrogen Ions ◽  
Hydrogen Atoms ◽  
Impurity Atoms ◽  
Radiation Fluxes ◽  
Start Up ◽  
Initial Stage ◽  
Light Impurities

Analyzing the dynamics of density for atomic and molecular hydrogen ions, the values of atomic hydrogen and UV radiation fluxes to the walls of the plasma chamber were obtained, resulting in light impurities of carbon and oxygen at plasma start-up during the process of desorption from the walls under irradiation. The fluxes of impurity atoms associated with the fluxes of photons and hydrogen atoms in a discharge are determined. Recommendations are given to reduce the amount of impurities at the initial stage of discharge.

Spin generation and manipulation based on spin-orbit interaction in semiconductors

2017 ◽  
Author(s):  
J. Nitta
Keyword(s):  
Magnetic Field ◽  
Orbit Interaction ◽  
Degree Of Freedom ◽  
Effective Magnetic Field ◽  
Spin Orbit ◽  
Spin Orbit Interaction ◽  
Spin Degree ◽  
Dimensional Electron Gas ◽  
Spin Orbit Interactions ◽  
Electrical Generation

This chapter focuses on the electron spin degree of freedom in semiconductor spintronics. In particular, the electrostatic control of the spin degree of freedom is an advantageous technology over metal-based spintronics. Spin–orbit interaction (SOI), which gives rise to an effective magnetic field. The essence of SOI is that the moving electrons in an electric field feel an effective magnetic field even without any external magnetic field. Rashba spin–orbit interaction is important since the strength is controlled by the gate voltage on top of the semiconductor’s two-dimensional electron gas. By utilizing the effective magnetic field induced by the SOI, spin generation and manipulation are possible by electrostatic ways. The origin of spin-orbit interactions in semiconductors and the electrical generation and manipulation of spins by electrical means are discussed. Long spin coherence is achieved by special spin helix state where both strengths of Rashba and Dresselhaus SOI are equal.

Water and Atomic Hydrogen Adsorption on Magnetite (001)

2019 ◽  
Vol 123 (43) ◽  
pp. 26662-26672 ◽  
Author(s):  
Björn Arndt ◽  
Marcus Creutzburg ◽  
Elin Grånäs ◽  
Sergey Volkov ◽  
Konstantin Krausert ◽  
...  
Keyword(s):  
Atomic Hydrogen ◽  
Hydrogen Adsorption

scholarly journals Intersystem crossing processes in the 2CzPN emitter: a DFT/MRCI study including vibrational spin–orbit interactions

2021 ◽  
Vol 23 (5) ◽  
pp. 3668-3678
Author(s):  
Angela Rodriguez-Serrano ◽  
Fabian Dinkelbach ◽  
Christel M. Marian
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Intersystem Crossing ◽  
Spin Orbit ◽  
Spin Orbit Interactions

Multireference quantum chemical calculations were performed in order to investigate the (reverse) intersystem crossing ((R)ISC) mechanisms of 4,5-di(9H-carbazol-9-yl)-phthalonitrile (2CzPN).

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