Magnetic properties of hard-soft SrFe10Al2O19/Co0.8Ni0.2Fe2O4 ferrite synthesized by one-pot sol–gel auto-combustion

2016 ◽  
Vol 416 ◽  
pp. 408-416 ◽  
Author(s):  
Shahab Torkian ◽  
Ali Ghasemi ◽  
Reza Shoja Razavi
2018 ◽  
Vol 12 (3) ◽  
pp. 248-256 ◽  
Author(s):  
Faezeh Tavakolinia ◽  
Mohammad Yousefi ◽  
Seyyed Afghahi ◽  
Saeid Baghshahi ◽  
Susan Samadi

SrFe12O19/Zn0.4Co0.2Ni0.4Fe2O4 hard/soft ferrite composite particles with 20, 40, 60 and 80 wt.% of soft phase were prepared by one-pot sol-gel auto-combustion and physical mixing methods. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM) were used to characterize the structural and magnetic properties of the samples. XRD spectrum revealed the formation of mixed ferrite phases in the composite particles. The hysteresis loops of the samples showed the presence of exchange coupling between the hard and soft ferrites. The composite particles with 20 and 60 wt.% of the soft phase demonstrated the highest Mr/Ms ratio, i.e. 0.29 and 0.28, respectively. In addition, the highest Ms, Mr and Hc were achieved in the composite particles with 40, 60 and 20 wt.% of the soft phase, respectively. Compared to the physical mixing method (PM), the composite particles prepared by the sol-gel auto-combustion method (OP) demonstrated better magnetic properties. The exchange coupling interaction between the hard and soft ferrite phases was similar in both methods. These composite particles exhibited magnetically single phase behaviour, however, the saturation magnetization was lower in the physical mixing pared to that of the one-pot method.


2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.


2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.


2019 ◽  
Vol 15 ◽  
pp. 6056-6077
Author(s):  
Ahmed Hassan Ibrahim ◽  
Yehia Mohammed Abbas ◽  
Shehab Esmail Mohammed ◽  
Ahmed Bakry Mansour

In this work, we studied the structural and magnetic properties of multiferroic La1-xYxFeO3 perovskites, (x= 0.0, 0.05, 0.1, 0.15, 0.25 and 0.3) which synthesized through Sol-gel auto-combustion technique using a citric acid as a fuel. The room temperature synchrotron X-ray diffraction (XRD) analysis revealed that the all the synthesized samples consisted of the polycrystalline orthorhombic structure perovskites(space group pnma), and tolerance factor confirmed the phase stability of the prepared perovskite system.The Williamson-Hall plot based on synchrotron XRD data were employed to estimate the average particle diameter and varies from 18 nmto 27.8 nm.For a deeper insight of the crystal structure, high resolution transmission microscopy imaging (HRTEM) was performed. The estimated values of crystallite size from HRTEM and synchrotron XRD data were coincident. Many of crystallographic parameters and electron density measurements were calculated by Rietveld refinement of synchrotron XRD data. La1-xYxFeO3 perovskite crystalsarecanted antiferromagnets with a weak ferromagnetism in room temperature.The magnetic properties were gotten through analyzing the magnetization versus temperature M(T) and M(H) hysteresis loop which characterized by a vibrating sample magnetometer (VSM). The molecular structure showed the decrease of the tilting of the octahedra <FeO6> with increasing Y content trying to strengthen the ferromagnetic character. Selected Area Electron Diffraction (SAED) patterns of the investigated samples exhibited spotty ring patterns,confirming the polycrystalline character.The orthoferrite La1-xYxFeO3 crystalsare a promising candidate for optical device applications in broad temperature range and high power system.


2020 ◽  
Vol 817 ◽  
pp. 152786 ◽  
Author(s):  
Mohammed S. Al Maashani ◽  
Kadhim A. Khalaf ◽  
Abbasher M. Gismelseed ◽  
Imaddin A. Al-Omari

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