Synthesis of SrMnSn Dy0.01Fe0.99O19 Ferrite Nanoparticles and Microwave Absorption Characterization

Ali-Sharbati,; Khani, Javad-Mola Verdi

doi:10.2174/1573413711309010018

Cited by 2 publications

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“…9 Hexaferrites were first developed in Japan by Y. Kato more than 85 years ago, and Japan has since maintained its leadership in this field. 10 During the past half century M-type ferrites with the formula MFe 12 O 19 (M = Ba, Sr, Pb, Ca), important magnetic materials, have been used for shielding of electromagnetic waves of gigahertz frequency. Many researchers have reported that the BaM and SrM-type ferrites 11,12 can function as microwave absorbers in the gigahertz region if Fe 3+ ions are substituted with other ions.…”

Section: Introductionmentioning

confidence: 99%

Structural, Magnetic, and Microwave-Absorption Properties of Nanocrystalline Ca(MnSn) x Fe12−2x O19 Ferrites

Ali-Sharbati

Amiri

Mousarezaei

2014

Journal of Elec Materi

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Nanoparticles of Ca(MnSn) x Fe 12À2x O 19 with x ranging from 0.00 to 0.6 in steps of 0.2 were prepared by use of the citrate precursor method. The structural, microwave-absorption, and magnetic properties of these ferrites were determined by use of different characterization techniques. The morphology of the ferrite powders was investigated by transmission electron microscopy (TEM). X-ray diffraction (XRD) was used for structural and micro-structural studies, and revealed that the samples had an M-type hexagonal structure. The crystallite size for each sample was calculated by use of the Scherrer formula for the most intense peak (411) and the results were compared with those obtained from TEM images of the samples. The particle size of the powder varied from 60 to 36 nm. Magnetic measurements were performed by vibrating sample magnetometry (VSM) at room temperature. The microwaveabsorption properties of ferrite (70 wt.%)-polymer (30 wt.%) composites 2 mm thick were investigated by vector network analysis (VNA) in the frequency range 12-20 GHz. The ferrite for which x = 0.4 had a minimum reflection loss of À29 dB at 17.3 GHz with a À15 dB bandwidth over the extended frequency ranges 12.9-14.5 GHz and 16.7-18 GHz. The minimum loss reached À32 dB at frequency of 17 GHz when the total amount of Mn 2+ and Sn 4+ ions was 0.6. These results suggest that the synthesized magnetic composites can be used as effective microwave absorbers in military applications (radar cross-section reduction).

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Section: Introductionmentioning

confidence: 99%

Structural, Magnetic, and Microwave-Absorption Properties of Nanocrystalline Ca(MnSn) x Fe12−2x O19 Ferrites

Ali-Sharbati

Amiri

Mousarezaei

2014

Journal of Elec Materi

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Structural and Magnetic Properties of Sn⁴⁺ Doped Strontium Hexaferrites Prepared via Sol–Gel Auto-Combustion Method

et al. 2018

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Sn-Zn-Co-substituted strontium M-type hexaferrite SrZn x Co x Sn 2x Fe 12−4x O 19 (x = 0.0, 0.3, 0.5, and 0.7) was synthesized via modified sol-gel auto-combustion method. A microwave device was used to obtain the finest particles and to complete the combustion process. By substitution of tetravalent and divalent cations instead of iron, magnetic and structural properties of M-type hexaferrite were changed. So, the effects of Sn 4+ , Zn 2+ , and Co 2+ doping on the structure and magnetic characterization of M-type hexaferrite were investigated. The Fourier transform infrared spectroscopy revealed bands at 430 and 590 cm −1 , related to the stretching vibrating bonds of Fe-O. The X-ray diffraction analysis showed that all samples prepared were of P6 3 /mmc symmetry and average crystal size of 68 nm. Field emission scanning electron microscopy analysis revealed the hexagonal plateletlike shape of all samples. Vibrating sample magnetometer results showed that by increasing the dopants content, coercivity (H c), and saturation magnetization (M s) changed drastically. Saturation magnetizations decreased during dopants displacement and then reach to the highest value (65.46 emu/g) at x = 0.5 then increasing of dopants to x = 0.7, cause the reduction of M s (56.13 emu/g). Coercivity diminished by dopant substitution and the semi-hard samples were received as an alternative to the hard hexaferrite. Index Terms-Coercivity (H c), M-type hexaferrite, saturation magnetization (M s), sol-gel auto-combustion. I. INTRODUCTION M-TYPE hexagonal ferrites with high coercivity, high Curie temperature, high electrical resistivity, and large magnetocrystalline anisotropy along the c-axis are beneficial materials [1]-[4]. The usage of these materials as a permanent magnet, data recording media, super capacitors, and microwave absorbers was prevailed [5], [6]. The unit cell of M-type hexaferrites consists of S and R blocks. S block is made of Fe 6 O 2+ 8 unit and the R block is built of MFe 6 O 2− 11. Iron in the hexagonal structure occupied five different sites in tetrahedral 4f 1 (↓), bipyramidal 2b (↑), and three octahedral sites [12 K (↑), 4f 2 (↓), and 2a (↑)]. By substitution of Fe 3+ in 12 K (↑), 4f 2 (↓), or 2a (↑) sites with tetravalent cations such as Ti 4+ , Zr 4+ , and Sn 4+ and some divalent cations, for example, Cu 2+ , Ni 2+ , and Co 2+ , magnetic and structural properties of hexaferrites were changed [7]-[10]. Since the occupation of Sn 4+ as a dopant on the hexaferrite structure was investigated rarely [16], we were interested in studying magnetic, and structural doping effects of this cation. Many synthesis methods such as sol-gel [11], hydrothermal [12], co-precipitation [13], and microemulsion [14] have been used to prepare strontium hexaferrites [15]. Unlike other methods, sol-gel auto-combustion demonstrated to be costeffective without any expensive precursors for the synthesis and the synthesis procedures are time-consuming. In this paper, Sn-Zn-Co-substituted strontium hexaferrite was prepared by a novel sol-gel ...

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Synthesis of SrMnSn Dy0.01Fe0.99O19 Ferrite Nanoparticles and Microwave Absorption Characterization

Cited by 2 publications

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Structural, Magnetic, and Microwave-Absorption Properties of Nanocrystalline Ca(MnSn) x Fe12−2x O19 Ferrites

Structural, Magnetic, and Microwave-Absorption Properties of Nanocrystalline Ca(MnSn) x Fe12−2x O19 Ferrites

Structural and Magnetic Properties of Sn⁴⁺ Doped Strontium Hexaferrites Prepared via Sol–Gel Auto-Combustion Method

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Synthesis of SrMnSn Dy0.01Fe0.99O19 Ferrite Nanoparticles and Microwave Absorption Characterization

Cited by 2 publications

References 0 publications

Structural, Magnetic, and Microwave-Absorption Properties of Nanocrystalline Ca(MnSn) x Fe12−2x O19 Ferrites

Structural, Magnetic, and Microwave-Absorption Properties of Nanocrystalline Ca(MnSn) x Fe12−2x O19 Ferrites

Structural and Magnetic Properties of Sn4+ Doped Strontium Hexaferrites Prepared via Sol–Gel Auto-Combustion Method

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Structural and Magnetic Properties of Sn⁴⁺ Doped Strontium Hexaferrites Prepared via Sol–Gel Auto-Combustion Method