Hybrid hematite/calcium ferrite fibers by solution blow spinning: Microstructural, optical and magnetic characterization

Autor(es)

Araujo, R. N. ^{[1, 2]} ; Nascimento, E. P. ^{[1, 2]} ; Raimundo, R. A. ^{[3, 4]} ; Macedo, D. A. ^[5] ; Mastelaro, V. R. ^[6] ; Neves, G. A. ^[2] ; Morales, M. A. ^[4] ; Menezes, R. R. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Campina Grande, Grad Program Mat Sci & Engn, Campina Grande, Paraiba - Brazil

^[2] Univ Fed Campina Grande, Lab Mat Technol, Campina Grande, Paraiba - Brazil

^[3] Univ Fed Paraiba, Grad Program Mech Engn, Joao Pessoa, Paraiba - Brazil

^[4] Univ Fed Rio Grande do Norte, Dept Theoret & Expt Phys, Natal, RN - Brazil

^[5] Univ Fed Paraiba, Dept Mat Engn, Joao Pessoa, Paraiba - Brazil

^[6] Univ Sao Paulo, Sao Carlos Inst Phys, Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CERAMICS INTERNATIONAL; v. 47, n. 23, p. 33363-33372, DEC 1 2021.
• Citações Web of Science: 0

Resumo

Iron oxide and Ca-doped ferrite fibers were successfully prepared via Solution Blow Spinning (SBS). Fibers with several calcium contents (nFe/nCa = 3.0, 5.2, and 20.0 atomic ratio) were prepared after dissolving polyvinylpyrrolidone and Fe and Ca nitrates in an acidic aqueous solution, followed by SBS spinning and calcination at 800 degrees C. The morphological, structural, optical, vibrational, and magnetic properties of the fibers were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), Mo spacing diaeresis ssbauer spectroscopy, and magnetometry. The Rietveld refinement revealed Ca-doped fibers consisting of a mixture of Fe2O3, CaFe2O4, and Ca3.6Fe14.4O25.2 crystalline phases. The Mo spacing diaeresis ssbauer spectra at 300 K showed a sextet belonging to the hematite phase and two doublets belonging to the calcium-related phases. Measurements at low temperatures showed a transition at 181.6 K attributed to Ca ferrite. The hematite fibers showed a saturation magnetization (Ms similar to 0.75 emu/g) relatively higher than the bulk alpha-Fe2O3 (Ms = 0.3 emu/g). The saturation magnetization increased from 3.6 to 6.4 emu/g with increasing Ca content. (AU)

• Processo FAPESP: 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs