Magnetic, structural and cation distribution studies on FeO center dot Fe(2-x)NdxO3 (x=0.00, 0.02, 0.04, 0.06 and 0.1) nanoparticles

Autor(es)

Araujo, W. W. R. ^[1] ; Araujo, J. F. D. F. ^[2] ; Oliveira, C. L. P. ^[1] ; Brito, G. E. S. ^[1] ; Figueiredo Neto, A. M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Phys, Rua Matao 1371, BR-05508090 Sao Paulo, SP - Brazil

^[2] Pontifical Catholic Univ Rio de Janeiro, Dept Phys, Rio De Janeiro, RJ - Brazil

• Tipo de documento: Artigo Científico
• Fonte: EUROPEAN PHYSICAL JOURNAL E; v. 42, n. 12 DEC 2019.
• Citações Web of Science: 0

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