Investigation of the Structural and Magnetic Properties of BaM Hexaferrites Prepared from Scrap Iron Filings

2021 ◽  
Vol 14 (4) ◽  
pp. 287-299
Keyword(s):  
Magnetic Properties ◽  
Magnetic Recording ◽  
Barium Carbonate ◽  
Oxide Phase ◽  
Magnetic Oxide ◽  
Sem Images ◽  
Conventional Solid State Reaction ◽  
Scrap Iron ◽  
Xrd Patterns ◽  
High Density Magnetic Recording

Abstract: In this work, we demonstrate the feasibility of preparing a commercially important type of magnetic oxide, BaM (BaFe12O19) hexaferrite, using scrap iron filings as an iron source. The hexaferrites were prepared by conventional solid state reaction and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and magnetization measurements. XRD patterns of samples prepared by mixing powders extracted from the iron filings with appropriate amounts of barium carbonate and sintering at 1200 °C revealed the presence of a major BaM hexaferrite with small amounts of nonmagnetic α-Fe2O3 oxide phase. On the other hand, SEM images of the samples showed clear crystallization of perfect hexagonal platelets of BaM hexaferrite, which was further confirmed by the Curie temperature determined from the thermomagnetic measurements. The saturation magnetization of the samples was in the range of 45.1– 52.1 emu/g and the remnant magnetization in the range of 14.8 – 19.0 emu/g. These values and the moderate coercivity of ~ 1 kOe suggest that the prepared samples could potentially be useful for high-density magnetic recording. Keywords: Hexaferrite, Solid waste, Magnetic Properties, Structural properties, Magnetic recording.

Preparation and Characterization of NTC NiMn2O4-La1-xCaxMnO3 (0≤x≤0.3) Composite Ceramics

2013 ◽  
Vol 716 ◽  
pp. 78-83 ◽  
Author(s):  
Hui Min Zhang ◽  
Fang Guan ◽  
Ai Min Chang ◽  
Li Jun Zhao
Keyword(s):  
Electrical Resistivity ◽  
Perovskite Structure ◽  
Spinel Structure ◽  
Thermal Constant ◽  
Inrush Current ◽  
Composite Ceramics ◽  
Sem Images ◽  
Conventional Solid State Reaction ◽  
Different Temperatures ◽  
Xrd Patterns

Composite ceramics made of spinel structure NiMn2O4 and CaO-doped perovskite structure LaMnO3 were prepared by a conventional solid state reaction and sintered at different temperatures. The XRD patterns have shown that the major phases presented in the sintered samples are NiMn2O4 compounds with the spinel structure, La1-xCaxMnO3 with the perovskite structure and NiO with a monoclinic structure. SEM images show that the density and grain size of the composite ceramics increases with sintered temperature increasing. The electrical resistivity of the composite ceramics at 25°C is found to change significantly depending on the CaO content, while the thermal constant B is still reasonably large in the range of 2400 to 3000 K. For the composition x = 0.1, the composite with a low electrical resistivity (ρ25°C=4.46Ω·cm) and moderate B value (B25/50=2762K) was obtained. These composites could be applied as potential candidates for NTC thermistors in the suppression of the inrush current.

Synthesis and Magnetic Properties of Co Nanorod Superlattices

2006 ◽  
Vol 962 ◽  
Author(s):  
Fabienne Wetz ◽  
Katerina Soulantica ◽  
Marc Respaud ◽  
Andrea Falqui ◽  
Bruno Chaudret
Keyword(s):  
Thermal Decomposition ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Magnetic Recording ◽  
Coercive Field ◽  
Shape Control ◽  
Room Temperature ◽  
High Density ◽  
High Density Magnetic Recording ◽  
Long Chain

ABSTRACTWe present the synthesis and magnetic properties of Co nanorods spontaneously organized in superlattices over a surface of several microns. This material results from the thermal decomposition of a cobalt precursor under hydrogen, in the presence of a long-chain amine and a long-chain acid as shape control agents. These nanorod superlattices are ferromagnetic at room temperature and they are characterized by a strong coercive field as a consequence of their large magnetic anisotropy. This system can be considered as a good candidate for high density magnetic recording.

scholarly journals Effect of Y3+ Substitution on Structural and Magnetic Properties of Ni0.25 Zn0.75YxFe2-xO4

2020 ◽  
Vol 68 (2) ◽  
pp. 111-116
Author(s):  
Sharmin Akhter ◽  
Probal Roy ◽  
Armin Anwar ◽  
MA Hossain ◽  
MNI Khan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Solid State Reaction Method ◽  
Industrial Applications ◽  
Ferromagnetic Behavior ◽  
Conventional Solid State Reaction ◽  
Spinel Type ◽  
Sem Micrographs ◽  
Ray Density ◽  
Structural And Magnetic Properties ◽  
Xrd Patterns

The effect of Y3+ doping on the structural and magnetic properties of Ni0.25 Zn0.75YxFe2-xO4 [x= 0.00, 0.02, 0.04, 0.06 and 0.08] was investigated. The specimen was synthesized by conventional solid state reaction method where the sintering temperature was 1150oC for 3 hours. The structure of the specimens was inspected by XRD pattern and SEM micrographs. The XRD patterns delineate the formation of spinel type cubic structure. The lattice parameters, bulk density, X-ray density and porosity were investigated for all the samples. The SEM micrographs shows that the particles of all the composition are within 0.4 – 1.2 μm. M-H curves at room temperature exhibit the ferromagnetic behavior. The effect of Y3+ causes drastically variation on saturation magnetization (Ms), coercivity (Hc) and remanent magnetization (Mr). Moreover, the M-H curves delineate the soft ferromagnetic phenomenon which can be the reason of the acceptance of the specimen in industrial applications. Dhaka Univ. J. Sci. 68(2): 111-116, 2020 (July)

scholarly journals Structural and Magnetic Properties of (Mg, Co)2W Hexaferrites

2020 ◽  
Vol 13 (1) ◽  
pp. 1-16
Keyword(s):  
Magnetic Properties ◽  
Sintering Temperature ◽  
High Energy ◽  
Spin Reorientation ◽  
Magnetic Data ◽  
Sem Images ◽  
Intermediate Phases ◽  
Structural And Magnetic Properties ◽  
Xrd Patterns ◽  
Precursor Powders

Precursor powders of BaMg2-xCoxFe16O27 with (x = 0.0, 1.0, and 2.0) were prepared using high-energy ball milling and the effects of chemical composition and sintering temperature on the structural and magnetic properties were investigated using x-ray diffractometer (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). XRD patterns of the prepared samples indicated that crystallization of pure BaW hexaferrite phase was achieved at a sintering temperature of 1300° C, while BaM and cubic spinel intermediate phases were obtained at lower sintering temperatures of 1100° C and 1200° C. SEM images revealed an improvement of crystallization of the structural phases and a growth of the particle size with increasing the sintering temperature. The magnetic data of the samples sintered at 1300° C revealed an increase of the saturation magnetization from 59.4 emu/g to 72.6 emu/g with increasing Co concentration (x) from 0.0 to 2.0. The coercive field Hc decreased from 0.07 kOe at x = 0.0 to 0.03 kOe at x = 1.0 and then increased to 0.09 kOe at x = 2.0. The thermomagnetic curves of the samples sintered at 1300° C confirmed the existence of the W-type phase and revealed spin reorientation transitions in Co-containing samples.

scholarly journals Effect of Gd doping on Structural, Morphological and Magnetic Properties of Mn-Zn Soft Ferrites Nanoparticles

2021 ◽  
Author(s):  
Anjali Shrivastava ◽  
Ashwani Kumar Shrivastava
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Morphological Characteristics ◽  
Lattice Parameter ◽  
Nano Particles ◽  
Sem Images ◽  
Manganese Zinc ◽  
Manganese Zinc Ferrite ◽  
Xrd Patterns ◽  
Co Precipitation

Abstract Co-precipitation technique was adopted to synthesize gadolinium doped manganese-zinc ferrite nano particles with varying concentration 0, 0.1, 0.2 and 0.3. XRD patterns authenticated the ferrite innovate in the as-prepared samples. The lattice parameter, crystallite size, lattice strain and x-ray density has been calculated. The crystallite size is comes bent on be around 5 nm. The FTIR spectra reveal that every one the functional groups are present within the material. SEM images are accustomed to indicate the morphological characteristics of the as-prepared samples. Magnetic properties show the decrease in saturation magnetization from 37.57emu/g to 30.15emu/g with reference to increase in gadolinium doping from 0.1 to 0.3.

FePt Nanocluster Films for High-Density Magnetic Recording

2007 ◽  
Vol 7 (1) ◽  
pp. 206-224 ◽  
Author(s):  
Y. F. Xu ◽  
M. L. Yan ◽  
D. J. Sellmyer
Keyword(s):  
Magnetic Properties ◽  
Magnetic Recording ◽  
Composite Films ◽  
Areal Density ◽  
Nanocomposite Films ◽  
Recording Media ◽  
Perpendicular Media ◽  
High Anisotropy ◽  
Self Assembled ◽  
High Density Magnetic Recording

High anisotropy L10 ordered FePt thin films are considered to have high potential for use as high areal density recording media, beyond 1 Tera bit/in2. In this paper, we review recent results on the synthesis and magnetic properties of L10 FePt nanocomposite films. Several fabrication methods have been developed to produce high-anisotropy FePt films: epitaxial and non-epitaxial growth of (001)-oriented FePt:X (X = Au, Ag, Cu, C, etc.) composite films that might be used for perpendicular media; monodispersed FePt nanocluster-assembled films grown with a gas-aggregation technique and having uniform cluster size and narrow size distribution; self-assembled FePt particles prepared with chemical synthesis by reduction/decomposition techniques, etc. The magnetic properties are controllable through variations in the nanocluster properties and nanostructure. FePt and related films show promise for development as heat-assisted magnetic recording media at extremely high areal densities. The self-assembled FePt arrays show potential for approaching the ultimate goal of single-grain-per-bit patterned media.

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