Search

type:text, The Compton profile of the Ba doped silicon clathrate (Ba 8Si46) has been studied using the high-resolution Compton scattering technique. The Compton profile is sensitive to the change of wave functions, and the good agreement between experiment and theory validates a theoretical prediction. A difference Compton profile between the Ba doped and nondoped clathrates (Si136) has been experimentally obtained and compared with that of a first-principles band structure calculation. The experiment and calculation show excellent agreement with respect to the overall shape in the profile. Analyses of partial density of the states (DOS) predict that, by doping Ba atoms into the Si cages, Ba 6s electrons are transferred into Ba 5d orbitals that are strongly hybridized with Si 3p orbitals. The hybridized states form a sharp peak of the DOS in close vicinity of the Fermi level, which plays an important role for the occurrence of superconductivity in Ba 8Si46.

The Compton profile of the Ba doped silicon clathrate (Ba 8Si46) has been studied using the high-resolution Compton scattering technique. The Compton profile is sensitive to the change of wave functions, and the good agreement between experiment and theory validates a theoretical prediction. A difference Compton profile between the Ba doped and nondoped clathrates (Si136) has been experimentally obtained and compared with that of a first-principles band structure calculation. The experiment and calculation show excellent agreement with respect to the overall shape in the profile. Analyses of partial density of the states (DOS) predict that, by doping Ba atoms into the Si cages, Ba 6s electrons are transferred into Ba 5d orbitals that are strongly hybridized with Si 3p orbitals. The hybridized states form a sharp peak of the DOS in close vicinity of the Fermi level, which plays an important role for the occurrence of superconductivity in Ba 8Si46.

The Compton profile of the Ba doped silicon clathrate (Ba 8Si46) has been studied using the high-resolution Compton scattering technique. The Compton profile is sensitive to the change of wave functions, and the good agreement between experiment and theory validates a theoretical prediction. A difference Compton profile between the Ba doped and nondoped clathrates (Si136) has been experimentally obtained and compared with that of a first-principles band structure calculation. The experiment and calculation show excellent agreement with respect to the overall shape in the profile. Analyses of partial density of the states (DOS) predict that, by doping Ba atoms into the Si cages, Ba 6s electrons are transferred into Ba 5d orbitals that are strongly hybridized with Si 3p orbitals. The hybridized states form a sharp peak of the DOS in close vicinity of the Fermi level, which plays an important role for the occurrence of superconductivity in Ba 8Si46.

type:text, Several doped type-I silicon clathrates (Na8 @Si46, K8@Si46, Ba8@Si46 and I8@Si46) have been investigated both experimentally by inelastic neutron scattering and x-ray-absorption spectroscopy and theoretically by ab initio calculations. We find that Ba atoms have a stronger coupling with the host lattice than Na or K ones. We show that in the superconductor Ba8@Si46 the coupling is effectively done by host acoustic phonons exciting guest acoustic modes. These features suggest that the host-guest vibrational coupling is a crucial parameter to explain the appearance of superconductivity in addition to the density of states near the Fermi level.

Several doped type-I silicon clathrates (Na8 @Si46, K8@Si46, Ba8@Si46 and I8@Si46) have been investigated both experimentally by inelastic neutron scattering and x-ray-absorption spectroscopy and theoretically by ab initio calculations. We find that Ba atoms have a stronger coupling with the host lattice than Na or K ones. We show that in the superconductor Ba8@Si46 the coupling is effectively done by host acoustic phonons exciting guest acoustic modes. These features suggest that the host-guest vibrational coupling is a crucial parameter to explain the appearance of superconductivity in addition to the density of states near the Fermi level.

Several doped type-I silicon clathrates (Na8 @Si46, K8@Si46, Ba8@Si46 and I8@Si46) have been investigated both experimentally by inelastic neutron scattering and x-ray-absorption spectroscopy and theoretically by ab initio calculations. We find that Ba atoms have a stronger coupling with the host lattice than Na or K ones. We show that in the superconductor Ba8@Si46 the coupling is effectively done by host acoustic phonons exciting guest acoustic modes. These features suggest that the host-guest vibrational coupling is a crucial parameter to explain the appearance of superconductivity in addition to the density of states near the Fermi level.

Avec mode texte

Several doped type-I silicon clathrates (Na8 @Si46, K8@Si46, Ba8@Si46 and I8@Si46) have been investigated both experimentally by inelastic neutron scattering and x-ray-absorption spectroscopy and theoretically by ab initio calculations. We find that Ba atoms have a stronger coupling with the host lattice than Na or K ones. We show that in the superconductor Ba8@Si46 the coupling is effectively done by host acoustic phonons exciting guest acoustic modes. These features suggest that the host-guest vibrational coupling is a crucial parameter to explain the appearance of superconductivity in addition to the density of states near the Fermi level.

The Compton profile of the Ba doped silicon clathrate (Ba 8Si46) has been studied using the high-resolution Compton scattering technique. The Compton profile is sensitive to the change of wave functions, and the good agreement between experiment and theory validates a theoretical prediction. A difference Compton profile between the Ba doped and nondoped clathrates (Si136) has been experimentally obtained and compared with that of a first-principles band structure calculation. The experiment and calculation show excellent agreement with respect to the overall shape in the profile. Analyses of partial density of the states (DOS) predict that, by doping Ba atoms into the Si cages, Ba 6s electrons are transferred into Ba 5d orbitals that are strongly hybridized with Si 3p orbitals. The hybridized states form a sharp peak of the DOS in close vicinity of the Fermi level, which plays an important role for the occurrence of superconductivity in Ba 8Si46.

Avec mode texte