Artigo de peri??dico
Characterization of Mn0.67Zn0.33Fe2O4 nanoparticles synthesized under different pH
Registro en:
1662-9752
899
10.4028/www.scientific.net/MSF.899.48
Autor
ICHIKAWA, RODRIGO U.
YOSHITO, WALTER K.
SAEKI, MARGARIDA J.
MARANHAO, WILLIAN C.A.
GOULART, FATIMA
MARTINEZ, LUIS G.
Resumen
Nanostructured Mn-Zn ferrites were synthesized using co-precipitation in alkaline
solution with different pH. The samples were characterized using X-ray diffraction (XRD), X-ray
fluorescence (XRF), thermal analysis (TG-DTA), dynamic light scattering (DLS) and scanning
electron microscopy (SEM) techniques. Monophasic nanoparticles were formed when synthesized
with pH 10.5. This sample was heat-treated and its XRD data was refined by the Rietveld method.
Mean crystallite sizes and microstrains were determined from X-ray line profile analysis using
Single-Line and Warren-Averbach methods, which revealed a mean crystallite size of
approximately 10 nm and negligible microstrains. Zn content was estimated using refined cell
parameters, giving a value of 33 at %, in accordance with XRF result. TG-DTA revealed that the
incorporation of ??-Fe2O3 occurs around 1130 ??C and 1200 ??C with recrystallization of the Mn-Zn
ferrite spinel phase. DLS showed that mean particle size increase with temperature up to 1159 nm
at 800 ??C. SEM analysis showed the samples agglomerate and present similar morphology with
negligible size changing when calcined between 280 ??C and 800 ??C. However, the sample calcined
at 1200 ??C presents larger agglomerates due to the sintering process.