INVESTIGADORES
MARTINEZ GARCIA Ricardo
congresos y reuniones científicas
Título:
Evidence of existence of metastable SrFe12O19 nanoparticles
Autor/es:
V. BILOVOL; RICARDO MARTÍNEZ GARCÍA; K. PIROTA; L. M. SOCOLOVSKY
Lugar:
Campinas, Sao Paulo, Brasil
Reunión:
Workshop; Reunión de Usuarios del LNLS (Laboratorio Nacional de Luz Sincrotrón); 2011
Institución organizadora:
Laboratorio Nacional de Luz Sincrotrón
Resumen:
The existence of metastable hexaferrite is reported. Synthesis of strontium hexaferrite, SrFe12O19, at 400ºC was realized under controlled oxygen atmosphere. Such technique allows obtaining SrFe12O19 at lower temperatures than those used by traditional methods (above to 800ºC). Phase transformation occurred during a measurement of magnetization vs. temperature (heating up to 625ºC). The heat treatment induces a change from SrFe12O19 to g-Fe2O3 (as main phase), and SrFeO2.74 to Sr2Fe2O5. Together with these phase transformations, an increment of the amount of SrCO3 is detected. Magnetic study of the samples, before and after the heating, supports the structural analysis conclusions. Up to our knowledge, this is the first report of the existence of metastable SrFe12O19.
