Hopkinson effect, structural and magnetic properties of M-type Sm3+-doped SrFe12O19 nanoparticles produced by a proteic sol–gel process

• Published in: Ceramics international Vol. 42; no. 5; pp. 5865 - 5872
• Main Authors: Buzinaro, M.A.P., Ferreira, N.S., Cunha, F., Macêdo, M.A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2016
• Subjects: M-type hexaferrite; Proteic sol–gel process; SrFe12O19; Proteic sol–gel process; M-type hexaferrite; SrFe12O19
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2015.12.130

Samarium doped M-type strontium hexaferrites with chemical formula Sr1−xSmxFe12O19 (0≤x≤0.15) (SrM) were synthesized using the proteic sol–gel process. This low cost and environment friendly method yields easily reproducible magnetic powders. The crystal structure and phase purity were studied by X-ray diffraction (XRD). All the XRD patterns have been analyzed by Rietveld refinement technique using the P63/mmc space group which showed crystallite size in the nanoscale. Results of field emission scanning electron microscope show that the grains are regular hexagonal platelets. The saturation magnetization reaches a minimum at x=0.10 and increases at higher concentrations. The coercivity increases with Sm3+ concentration. The remarkable appearance of a Hopkinson peak at the M vs. T curve indicates that particles of the sample are composed of a single domain particles.