Influence of vanadium spin-polarization on the dissolution of hydrogen in vanadium
Autor: | Sam Shallcross, Peter Zahn, Thomas Dziekan, Susanne Mirbt, Velimir Meded, Björgvin Hjörvarsson |
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Rok vydání: | 2009 |
Předmět: |
Materials science
Hydrogen Spin polarization Condensed matter physics Fermi level Vanadium chemistry.chemical_element Fermi energy Condensed Matter Physics Electronic Optical and Magnetic Materials Condensed Matter::Materials Science Tetragonal crystal system symbols.namesake chemistry Electrical resistivity and conductivity Density of states symbols Condensed Matter::Strongly Correlated Electrons |
Zdroj: | Physical Review B. 79 |
ISSN: | 1550-235X 1098-0121 |
Popis: | In this thesis the conductivity of strained materials has been investigated using density functional theory and a semiclassical transport theory based on the Boltzmann equation.In transition metals trends are reproduced without adjustable parameters. The introduction of one temperature dependent cross section allowed the reproduction of resistivity trends between 10 and 1000K.The effect of strain on transition metals in bcc and fcc structure was studied deforming the unit cell along the tetragonal deformation path. The anisotropy of the conductivity varied on wide range of the c/a-ratio. The orbitals at the Fermi level determined the principal behavior. Pairs of elements with permutated number of electrons and holes in the 4d band showed similar behavior. The concept of the tetragonal deformation was also applied on semiconductors.The deformation of Vanadium in X/V superlattices (X=Cr,~Fe,~Mo) due to Hydrogen loading depends on the properties of X. It was found that counteracting effects due to the presence of Hydrogen influence the conductivity.It is shown that a small magnetic moment of the V host reduces the hydrogen solubility. Depending on the magnitude of the tetragonal distortion of V, the hydrogen dissolution becomes favored for larger moments.Finally, extra charge filling of the bandstructure of Cr and Mo decreases the Fermi velocity and increases the density of states at the Fermi energy. |
Databáze: | OpenAIRE |
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