Navegando por Autor "Netto, Antônio Marques"

Agora exibindo 1 - 2 de 2
  • Nenhuma Miniatura disponível
    Item
    Positron annihilation studies in binary solid solutions of metal betadiketonates, using lifetime and doppler broadening spectroscopies.
    (1993) Machado, José Caetano; Porto, Arilza de Oliveira; Carvalho, Cornélio de Freitas; Magalhães, Welington Ferreira de; Netto, Antônio Marques
    Positron annihilation lifetime (LS) and Doppler broadening annihilation kadiation lineshape (DBARL) spectroscopies measurements were performed in several binary solid solutions of the general formula M(l-x,Gfx,L,3 where M = Al(II1) , Ga(II1) , or In(II1) , as matrix; G = Cr (111) , Mn (111) , Fe (111) , co (111) , Ru (111) , Rh(III), and Ir(III), as guest molecules, L = acetylacetone (acac) or dipivaloylmethane (dpm), and X = guest molecule mole fraction. The studied systems can be classified in two groups: the first one presenting only inhibition of positronium formation and the second one presenting inhibition and quenching effects. The inhibition and quenching constants were determined.
  • Nenhuma Miniatura disponível
    Item
    Positronium formation in lanthanide (III) trifluoroacetate with 3-picoline-N-oxide compounds.
    (2001) Netto, Antônio Marques; Carvalho, Cornélio de Freitas; Carvalho, Carlos Alberto Alves de; Sinisterra, Ruben Dario; Brito, Hermi Felinto de; Machado, José Caetano
    Positron annihilation lifetime and Doppler broadening annihilation radiation line shape on the salts Ln(CF3COO)3•xH2O and the adducts Ln(CF3COO)3(3-picNO)•xH2O (Ln=La–Pr, Sm–Lu and Y, and 3-picNO=3picoline-N-oxide, x in the range 0.75–1.33) were performed. Positroniumformation in the adducts, except for the europium complex, was observed. These results are discussed in terms of the electronic properties of the central metal ions.