| Texto completo | |
| Autor(es): |
Araujo, W. W. R.
;
Araujo, J. F. D. F.
;
Oliveira, C. L. P.
;
Brito, G. E. S.
;
Figueiredo Neto, A. M.
Número total de Autores: 5
|
| Tipo de documento: | Artigo Científico |
| Fonte: | EUROPEAN PHYSICAL JOURNAL E; v. 42, n. 12, p. 14-pg., 2019-12-01. |
| Resumo | |
We synthesized and characterized the colloidal suspensions of FeO center dot Fe(2-x) NdxO3 nanoparticles with x = 0.00, 0.02, 0.04, 0.06 and 0.1. The effect of the Fe3+ ion replacement by Nd3+ on the crystal structure is in-depth studied. The samples were characterized by the following techniques: X-ray diffraction (XRD), UV-Vis spectrophotometry, transmission electronic microscopy (TEM), small-angle X-ray scattering (SAXS), magnetization as a function of applied magnetic field (M-H loops) and magnetization as a function of temperature in zero-field-cooled and field-cooled regimes (ZFC-FC). From XRD cation distribution, structural parameters were extracted. The increasing in the bandgap is interpreted as a result of the higher interatomic separation with the doping. TEM micrographs reveal a polydisperse size and shape distribution of particles. The results for the volume-weighted average diameter measured by SAXS are consistent with those determined by XRD. From the M-H loops we found that the superparamagnetic (SPM) regime contributes with 95-97% for all samples, while only 3-5% contribution comes from the paramagnetic (PM) regime. The saturation magnetization increases in a steady manner upon increasing the Nd3+ ion molar ratio from 0.00 up to 0.06, reaching the maximum value of 105.8 +/- 0.4 Am-2/kg at x = 0.06. It is worth to mention that the result for the saturation magnetization value are higher than that of the bulk material. (AU) | |
| Processo FAPESP: | 14/50983-3 - INCT 2014: fluidos complexos |
| Beneficiário: | Antonio Martins Figueiredo Neto |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |