INVESTIGADORES
RAMAJO leandro Alfredo
congresos y reuniones científicas
Título:
Sintesys of BaTiO3 nanoparticles by pechini method: BaCO3 inhibition by different thermal treatments
Autor/es:
LEANDRO RAMAJO; ROXANO GIMENES; MARIA MARTA REBOREDO; MARIA APARECIDA ZAGHETE; MIRIAM SUSANA CASTRO
Lugar:
Toledo - España
Reunión:
Congreso; Electroceramics; 2006
Institución organizadora:
Sociedad Española de Cerámica y Vidrio
Resumen:
Different thermal treatments were studied in order to inhibit the BaCO3 formation during the synthesis of BaTiO3 powder by Pechini´s method. The synthesis of BaTiO3 starts at 250°C by the thermal dehydratation of organic precursors. The inevitable formation of BaCO3 phase in the thermal decomposition process of precursor could be retarded using lower decomposition temperatures. In order to achieve it, organic precursors were treated at different temperatures (between 200 and 400ºC). Then, the samples were calcinated at 700ºC. The organic precursors and ceramic powders generated were analyzed by thermal gravimetric analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD) and infrared spectroscopy (FTIR). DTA/TG analysis indicated that the thermal decomposition of the precursors proceeds through three major steps process: 1) dehydration reaction, 2) combustion reactions and intermediate phases formation, and 3) decarbonation of the intermediate compounds to give BaTiO3. X-ray diffraction and FTIR spectroscopy results indicated that, depending on the thermal treatment, BaCO3 and TiO2-x could be present in important amounts due to the higher organic matter concentration on the final furnace step (700ºC). Nevertheless the room temperature XRD results seem to indicate the formation of pseudo-cubic BaTiO3 as the final reaction product in all samples.