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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

tructural and magnetic properties of La-doped strontium-hexaferrites ceramics obtained by spark-plasma sinterin

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Author(s):
Govea-Alcaide, E. [1, 2] ; Matilla-Arias, J. [2] ; Guerrero, F. [1] ; Marino-Castellanos, P. [3] ; Montero-Rey, K. [4] ; Rosales-Saiz, F. [2] ; Machado, I. F. [5]
Total Authors: 7
Affiliation:
[1] Univ Fed Amazonas, Dept Phys, Manaus, Amazonas - Brazil
[2] Univ Granma, Fac Ciencias Tecn, Dept Ciencias Basicas & Informat Aplicada, Bayamo - Cuba
[3] Univ Holguin, Fac Ciencias Nat & Agr, Dept Fis, Holguin - Cuba
[4] Univ Sao Paulo, Inst Fis, Dept Fis Mat & Mecan, Sao Paulo, SP - Brazil
[5] Univ Sao Paulo, Dept Engn Mecatron & Sistemas Mecan, Escola Politecn, Sao Paulo, SP - Brazil
Total Affiliations: 5
Document type: Journal article
Source: Journal of Magnetism and Magnetic Materials; v. 533, SEP 1 2021.
Web of Science Citations: 0
Abstract

Polycrystalline samples of Sr1\_xLaxFe12O19 (x = 0.1, 0.3, and 0.6) hexaferrite were prepared by spark-plasma sintering (SPS) and its structural and magnetic properties have been investigated. The SPS process were performed under vacuum, at 900 C, and in only 5 min. X-ray powder diffraction patterns showed that before SPS sintering samples are composed by several phases where the SrFe12O19 (SrM) is not higher than 12%. From Rietveld refinement method, we have found that after SPS process the content of SrM phase increased, in mean, up to 68%. However, it was found the presence of secondary phase such as alpha-Fe2O3 and LaFeO3 (%) whose phase content also vary with increasing the La-content. A finite element simulation model were used to study the temperature evolution within the sample during the SPS treatment. Magnetization measurements at room temperature yielded values of saturation magnetization between - 43 to - 27 emu/g and coercivities, HcB, in the range 3.11 to 2.88 kOe with increasing x. The influence and possible interaction between detected magnetic phases was studied by means of first-order reversal curves (FORCs) measurements. Results indicated that magnetic behavior of the La-doped strontium hexaferrites obtained by SPS technique are analogous a system composed of a broad distribution particles that are exchange-coupled with a certain number of other of neighboring particles. From FORC maps the coercivity profiles of the studied samples were extracted. The asymmetric behavior of these profiles were related to a broad distribution of the particle size and/or the influence of the secondary magnetic phases. (AU)

FAPESP's process: 12/08068-0 - Synthesis of superconducting (Bi,Pb)2Sr2Ca2Cu3O10+y (Bi-2223) by spark plasma sintering
Grantee:Renato de Figueiredo Jardim
Support Opportunities: Research Grants - Visiting Researcher Grant - International