Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "swepub ;pers:(Johansson Börje);conttype:(refereed);srt2:(2010-2011);pers:(Eriksson Olle)"

Sökning: swepub > Johansson Börje > Refereegranskat > (2010-2011) > Eriksson Olle

  • Resultat 1-2 av 2
Sortera/gruppera träfflistan
  • Luo, Wei, et al. (författare)
  • Dynamical stability of body center cubic iron at the Earth's core conditions
  • 2010
  • Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 0027-8424. ; 107:22, s. 9962-9964
  • Tidskriftsartikel (refereegranskat)abstract
    • Here, using self-consistent ab initio lattice dynamical calculations that go beyond the quasiharmonic approximation, we show that the high-pressure high-temperature bcc-Fe phase is dynamically stable. In this treatment the temperature-dependent phonon spectra are derived by exciting all the lattice vibrations, in which the phonon-phonon interactions are considered. The high-pressure and high-temperature bcc-Fe phase shows standard bcc-type phonon dispersion curves except for the transverse branch, which is overdamped along the high symmetry direction Gamma-N, at temperatures below 4,500 K. When lowering the temperature down to a critical value T-C, the lattice instability of the bcc structure is reached. The pressure dependence of this critical temperature is studied at conditions relevant for the Earth's core.
  • Delczeg-Czirjak, E. K., et al. (författare)
  • Ab initio study of structural and magnetic properties of Si-doped Fe2P
  • 2010
  • Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 82:8, s. 085103
  • Tidskriftsartikel (refereegranskat)abstract
    • Ab initio electronic-structure methods are used to study the properties of Fe2P1-xSix in ferromagnetic and paramagnetic states. The site preference and lattice relaxation are calculated with the projector augmented wave method as implemented in the Vienna ab initio simulation package. The paramagnetic state is modeled by the disordered local magnetic moment scheme, and the chemical and magnetic disorder is treated using the coherent potential approximation in combination with the exact muffin-tin orbital formalism. The calculated lattice parameters, atomic positions, and magnetic properties are in good agreement with the experimental and other theoretical results. In contrast to the observation, for the ferromagnetic state the body centered ortho-rhombic structure (bco, space group I (mm2) under bar) is predicted to have lower energy than the hexagonal structure (hex, space group P (6) over bar 2m). The zero-point spin fluctuation energy difference is found to be large enough to stabilize the hex phase. For the paramagnetic state, the hex structure is calculated to be the stable phase and the computed total energy versus composition indicates a hex to bco crystallographic phase transition with increasing Si content. The phonon vibrational free energy, estimated from the theoretical equation of state, turns out to stabilize the hexagonal phase, whereas the electronic and magnetic entropies favor the low symmetry orthorhombic structure.
Skapa referenser, mejla, bekava och länka
  • Resultat 1-2 av 2
Typ av publikation
tidskriftsartikel (2)
Typ av innehåll
Ahuja, Rajeev, (1)
Luo, Wei, (1)
Punkkinen, M. P. J. (1)
Vitos, Levente, (1)
visa fler...
Arapan, Sergiu, (1)
Katsnelson, Mikhail ... (1)
Delczeg-Czirjak, E. ... (1)
Delczeg, L. (1)
Souvatzis, Petros, (1)
visa färre...
Uppsala universitet (2)
Kungliga Tekniska Högskolan (1)
Engelska (2)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (2)
Teknik (1)
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy