• Co-cubstitution effects on the Fe valence in the BaFe2As2 superconducting compound : a study of hard x-ray absorption spectroscopy 

      Bittar, Eduardo Matzenbacher; Adriano, C.; Garitezi, T. M.; Rosa, P. F. S.; Ferreira, Leticie Mendonca; Garcia, Flávio; Azevedo, Gustavo de Medeiros; Pagliuso, P. G. (2011) [Artigo de periódico]
      The Fe K x-ray absorption near edge structure of BaFe₂-xCoxAs₂ superconductors was investigated. No appreciable alteration in shape or energy position of this edge was observed with Co substitution. This result provides ...
    • High temperature emissivity, reflectivity, and x-ray absorption of BiFeO3 

      Massa, Néstor E.; Del Campo, Leire; Meneses, Domingos de Souza; Echegut, Patrick; Fabbris, Gilberto Fernandes Lopes; Azevedo, Gustavo de Medeiros; Martínez Lope, María Jesús; Alonso, José Antônio (2010) [Artigo de periódico]
      We report on the lattice evolution of BiFeO3 as function of temperature using far infrared emissivity, reflectivity, and x-ray absorption local structure. A power law fit to the lowest frequency soft phonon in the magnetic ...