INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Characterization of a mechanochemically activated titanium-hematite mixture: Mössbauer spectroscopy study
Autor/es:
A.A.CRISTÓBAL; C.P.RAMOS; P.M.BOTTA; E.F.AGLIETTI; C.B.SARAGOVI; J.M.PORTO LÓPEZ
Lugar:
Buenos Aires
Reunión:
Workshop; FCM 08: At the frontiers of condensed matter IV - Current trends and novel materials; 2008
Institución organizadora:
CNEA - UBA - U.N.San Martín
Resumen:
Characterization of a mechanochemically activated titanium-hematite mixture: Mössbauer spectroscopy study   Mechanochemical processes involving reactions between metals and crystalline oxides are of interest because their potential technological applications in structural, magnetic or electric materials. In addition they can contribute to the understanding of the natural occurring processes that lead to the formation of minerals and soils. The controlled studies of how the distribution of cations in the titanomagnetites takes place can help toward building a model for the nature of their magnetism and, since they are the primary carriers of rock and soil magnetism, are therefore intensively investigated in many experimental and theoretical studies. In behalf ofa better comprehension of the thermal, physical-chemical, magnetic and hyperfine behavior, we have considered a titanium and hematite mixtures, with molar ratio Ti:Fe2O3 of 1:2, mechanochemically activated during different activation times. We have studied the development of new phases by X-ray diffraction (XRD), scanning electron microscopy, differential thermal analysis and Mössbauer spectroscopy. The evolution from the starting materials affected by different milling times and subsequent annealing show that the Ti reduces the Fe ions in the Fe2O3 lattice, partly to Fe2+ and partly to metallic Fe. All these techniques reveal mainly the formation of a solid solution (formed by ulvospinel and magnetite) and also the appearance of metallic iron.