RESUMO
Bonding characteristics of liquid boron at 2500 K are studied by using high-resolution Compton scattering. An excellent agreement is found between the measurements and the corresponding Car-Parrinello molecular dynamics simulations. Covalent bond pairs are clearly shown to dominate in liquid boron along with the coexistence of diffuse pairs. Our study reveals the complex bonding pattern of liquid boron and gives insight into the unusual properties of this high-temperature liquid.
RESUMO
Metallic liquid silicon at 1787 K is investigated using x-ray Compton scattering. An excellent agreement is found between the measurements and the corresponding Car-Parrinello molecular dynamics simulations. Our results show persistence of covalent bonding in liquid silicon and provide support for the occurrence of theoretically predicted liquid-liquid phase transition in supercooled liquid states. The population of covalent bond pairs in liquid silicon is estimated to be 17% via a maximally localized Wannier function analysis. Compton scattering is shown to be a sensitive probe of bonding effects in the liquid state.
RESUMO
Magnetic Circular Dichroism (MCD) of Resonant Inelastic X-ray Scattering (RIXS) of 3d(5/2) --> 2p(3/2) decay (Ho Lalpha1) was measured at the Ho L(III)-edge in Ho3Fe5O12. The MCD-RIXS, in which the intermediate state has the 2p4f(n+1) configuration due to the quadrupolar transition of 2p --> 4f, was also observed at the pre-edge region of the Ho L(III)-edge. The obvious superposition of two peaks, which comes from the high-energy off-resonant Raman scattering and the fluorescence, could be found in both the RIXS and the MCD-RIXS when the energy of the incoming X-ray was 7eV higher than the white line. The dependence of the integration of the MCD-RIXS spectra on the incident x-ray energy could roughly reproduce the MCD of X-ray absorption spectra (XAS).