INVESTIGADORES
POZO LOPEZ Gabriela Del Valle
artículos
Título:
Effect of Milling Time on Fe/SiO2 System Prepared by Mechanical Alloying
Autor/es:
G. POZO LÓPEZ; S.P. SILVETTI
Revista:
PHYSICA B - CONDENSED MATTER
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2004 vol. 354 p. 141 - 144
ISSN:
0921-4526
Resumen:
The evolution of structure during the mechanical milling of the Fe+SiO2 mixture has been studied. From X-ray diffraction line analyses we obtained the average grain size, crystalline weight fraction and lattice distortion for different milling times. The precursors milled are annealed at 1000°C in air and characterized by their structure and magnetic properties. The heat treatment promotes the oxidation of Fe to hematite and some of magnetite. Thermal analysis at 1000°C was also performed in argon atmosphere. Thermal treatment favours the formation of Fe2SiO4 and Fe3O4, in addition to the precursors Fe and SiO2. In this situation the annealing produces a compound with a coercivity of 78.2 emu/g, whereas the annealing in air atmosphere induces a mixture with a coercivity of 4.6 emu/g. The magnetization is explained in terms of the random anisotropy model (RAM).
