scholarly journals Magnetic properties of SrFe12-xAlxO19

2015 ◽  
Vol 12 (1) ◽  
pp. 08-14 ◽  
Author(s):  
I Bsoul ◽  
W. I Da'as
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Lattice Constant ◽  
Hexagonal Lattice ◽  
Anisotropy Field ◽  
Solid State Reaction Method ◽  
Strontium Ferrite ◽  
Strontium Hexaferrite ◽  
Magnetic Data ◽  
Standard Pattern

In this work, pure and doped with Al (Aluminum) strontium hexaferrite (SrFe12-xAlxO19) were fabricated by solid state reaction method. The Al concentration (x) for the fabricated samples was varied from x=0.0 to x=0.6. Structural and magnetic properties of the fabricated samples were investigated. Analyses of XRD data showed that all samples of high quality, since the measured XRD patterns found to match the standard pattern for single phase of SrFe12O19. The lattice constants a and c were calculated. It was found that the replacement of Fe3+ with Al3+ ions in hexagonal strontium ferrite led to a negligible changes in lattice constant a, whereas the hexagonal lattice constant c found to decrease with increasing the substitution amount of Al. The crystallite size was also determined using the XRD data. It has been found that that Al3+ substitution for Fe3+ does not appreciably disturb the crystallinity of SrFe12-xAlxO19, since the crystallite size for all samples ranged from 83 – 72 nm. The magnetic data showed that doping of strontium with Al leads to a small decrease in saturation magnetization. Also it has been found that the doping of strontium ferrite with Al leads to an increase in the coercivity as a result of increasing of the anisotropy field.

Transformation of Structure, Magnetic Properties and Microwave Absorption Capability in Nd-Doped Strontium Hexaferrite

2020 ◽  
Vol 855 ◽  
pp. 255-260
Author(s):  
Mukhtar Effendi ◽  
Efi Solihah ◽  
Candra Kurniawan ◽  
Wahyu Tri Cahyanto ◽  
Wahyu Widanarto
Keyword(s):  
Magnetic Properties ◽  
Microwave Absorption ◽  
Solid State Reaction Method ◽  
Strontium Hexaferrite ◽  
Basic Material ◽  
X Ray Diffraction ◽  
Cell Parameters ◽  
Tetragonal Crystal ◽  
Capability Analysis ◽  
Natural Iron

The synthesize of Nd3+-strontium hexaferrite magnetic material by the solid-state reaction method has been successfully carried out. This study aims to determine the effect of Nd3+ on the structure, magnetic properties, and microwave absorption capability of the material. Preparation of (1-x)SrO:xNd2O3:6Fe2O3 where x = 0, 10, 20, and 30 mol% using basic material in the form of SrCO3 powder, Nd2O3 powder and Fe3O4 from natural iron sand. The characterization includes the X-Ray Diffraction (XRD) examination to determine the crystal structure, the Scanning Electron Microscope (SEM) for exploring the surface morphology, Vibrating Sample Magnetometer (VSM) for the magnetic properties investigation of material, and Vector Network Analyzer (VNA) for microwave absorption capability analysis. The XRD results show that the addition of Nd3+ doping increases the number of SrNdFeO4 phases. The phase has a tetragonal crystal system that has cell parameters a = b = 3.846 Å, and c = 12.594 Å. The magnetic properties of the material showed that the addition of Nd3+ decreased the saturation and remanence magnetization values, whereas the value of the coercivity field increased. Meanwhile, the best microwave absorption occurs in samples with the addition of Nd3+ as much as 0.3 mol, which results in a reflection loss value of -18.9 dB with a frequency bandwidth of 3.9 GHz.

Synthesis and Magnetic Properties of SrFe12-XCoxO19 (x= 0- 2) Hexaferrite Nanoparticles

2012 ◽  
Vol 622-623 ◽  
pp. 925-929 ◽  
Author(s):  
M. Zargar Shoushtari ◽  
S E. Mousavi Ghahfarokhi ◽  
F. Ranjbar
Keyword(s):  
Magnetic Properties ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Anisotropy Field ◽  
Strontium Hexaferrite ◽  
Nominal Composition ◽  
Second Phase ◽  
Energy Product ◽  
Crystalline Anisotropy ◽  
Magnetic Remanence

In this paper, a batch of M- type strontium hexaferrite samples with nominal composition of SrFe12-xCoxO19(where x= 0- 2), have been synthesized via sol- gel method. In the synthesis of samples, first a precursor gel was prepared, and then dry- gel was calcined at 1000°C for 2 hours to obtain the nano- SrFe12-xCoxO19. The XRD results revealed that for SrFe12-xCoxO19 samples with x≤0.5, all of them have single- phase hexaferrite structure and also this data suggests that the F 3+ ions are substituted by Co2+ ions in the crystallography sites of the SrFe12-xCoxO19, but for the samples with x>0.5, the second phase of CoFe2O4 is appeared and suggests that the Co2+ ions also make a distinct phase in the samples. The magnetic properties, such as saturation magnetization (Ms), magnetic remanence (Mr), magnetic coercivity (Hc), squareness ratio (Mr/Ms), crystalline anisotropy field (Ha), energy product [(BH)max] and the susceptibility χ as the derivative of M with respect to H of the upper branch of the hysteresis loop were discussed by measurements of M-H curves with vibrating sample magnetometer (VSM). The magnetic measurements revealed that the coercively (Hc) values of all the samples decrease with increasing dopant contents.

DC and AC Measurements of Magnetite Nanoparticulates and Implications for Nonlinear Response

2008 ◽  
Vol 1138 ◽  
Author(s):  
Silvia Liong ◽  
Ricky Lamar Moore
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Polymer Composites ◽  
Magnetic Measurements ◽  
Bulk Material ◽  
Low Frequency ◽  
Anisotropy Field ◽  
Coaxial Line ◽  
Magnetic Data ◽  
Order Of Magnitude

AbstractThis paper discusses preparation, characterization and measurement of linear DC and AC magnetic properties of magnetite (Fe3O4) nanoparticles (size ranges of 7-50 nm and 5 microns) and polymer composites of those particulates. Selected data and analysis are taken from the PhD thesis of Liong [1]. The goal of this research is to obtain magnetic data, specifically magnetization, anisotropy and coercivity as functions of particle size. These will be used as inputs to non linear magnetic simulations and in planning for future nonlinear magnetic measurements. Magnetite nanoparticles were synthesized by chemical coprecipitation, a method that allowed for the production of samples in gram quantities. Vibrating sample magnetometry was used to measure the room-temperature DC magnetization and coercivity of the particulates. Coaxial line impedance measurements were used to measure low frequency and dispersive AC permeability of Fe3O4–polymer composites from 1 Megahertz to 10 Gigahertz. AC data are applied to infer particulate magnetic susceptibility and anisotropy field change with particle size. Particle size was calculated from XTD data and supported by TEM images.Measured DC saturation magnetization and coercivity decreased with particle dimension while anisotropy was calculated to increase. Magnetization data are consistent with models that calculate nanoparticle magnetization as a volumetric average of a spherical bulk material core and a passive outer shell. The shell thickness was calculated at 0.84 nm, very near one lattice constant of bulk Fe3O4, 0.8394 nm. Composites containing particulate volume fractions less than 20% were fabricated. Effective media theory was applied to measured AC composite permeability to extract particle magnetic properties and thereby anisotropy field, which increased by an order of magnitude from the bulk. Permeability decreased with particulate size.

Structure and Magnetic Properties of Co-Substituted Strontium Hexaferrite

2014 ◽  
Vol 979 ◽  
pp. 200-203 ◽  
Author(s):  
Pannipa Chaya ◽  
Tula Jutarosaga ◽  
Wandee Onreabroy
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Coercive Force ◽  
Crystallite Size ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
Lattice Constants ◽  
Structure Morphology ◽  
Soft Ferrite

The strontium hexaferrite (SrFe12O19) and Co-substituted strontium hexaferrite (SrCoFe11O19) were prepared by ceramic method. The milled mixture of Fe2O3, SrCO3 and CoO powders were calcined at 1100°C and pellets sintered at 1300°C in air. The crystal structure, morphology and magnetic properties of samples have been investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM), respectively. The crystal structure of SrFe12O19 was hexaferrite with the crystallite size and the lattice constants a and c of 59.6 nm, 5.8 Å, and 23.0 Å, respectively. Also, the crystal structure of SrCoFe11O19 was hexaferrite with the crystallite size and the lattice constants a and c of 63.7 nm, 5.9 Å and 23.0 Å, respectively. The morphology of obtained samples changed from hexagonal rods to discs shape and grain sizes increased with the increase of doped Co in SrFe12O19. SrFe12O19 with the coercive force (Hc) of 2,133 Oe was classified as hard ferrite magnetic. While, Co-substituted strontium hexaferrite (SrCoFe11O19) was soft ferrite magnetic with coercive force of 64 Oe. Results indicated that magnetic properties of samples such as hard ferrite magnetic and soft ferrite magnetic showed great dependence on the cobalt additive in strontium.

scholarly journals Structural, Dielectric and Magnetic properties of Yttrium doped Hematite Nanoparticle

2021 ◽  
Author(s):  
Vijay Kumar ◽  
Dharamvir Singh Ahlawat ◽  
Amrik Singh ◽  
Arun Kumar ◽  
Ompal Singh
Keyword(s):  
Health Care ◽  
Grain Size ◽  
Magnetic Properties ◽  
Rare Earth ◽  
Crystallite Size ◽  
Data Storage ◽  
Rare Earth Metals ◽  
Magnetic Data ◽  
Xrd Patterns ◽  
Rhombohedral Symmetry

Abstract Applicability of magnetic crystalline nanoparticles particularly in the diagnostic field of health care and magnetic data storage makes them highly important for various technological researches. Novel properties of prepared nanoparticles can be tuned with doping of rare earth metals. In the present research, Yttrium (Y) doped hematite nanocrystalline samples have been prepared at various compositions, Fe2 − 2xY2xO3 (x = 0.00, 0.02, 0.05, 0.08, 0.10) and magnetic properties are seen sensitive with dopants concentration. The variation in grain size from FE-SEM is found well collaborated with the crystallite size and strain determined by XRD measurements. Rietveld refinement of XRD patterns reveals the formation of rhombohedral symmetry with Rˉ3c space group of the samples. The dielectric and magnetic properties show wiggling behaviour with the concentration of doping metal. A shift towards weakly ferromagnetic conduct like behaviour has been confirmed with the doping of Y in hematite crystalline particles.

scholarly journals Effect of Mechanical Milling on the Magnetic Properties of SrFe12O19

2015 ◽  
Vol 12 (1) ◽  
pp. 28-30
Author(s):  
I Bsoul
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Crystallite Size ◽  
Mechanical Milling ◽  
Single Phase ◽  
Strontium Ferrite ◽  
Single Domain ◽  
Single Domain Particle ◽  
Ferrite Sample

In this work, a single phase strontium ferrite sample was mechanically milled for 60 h. It has been found that the crystallite size reduced by 85%. A dramatic drop (from 4500 to 1600 Oe) in the coercive filed was also observed. The observed reduction in the coercivity was attributed to the reduction of the single domain particle size.

Effect of the structural changes on the mechanical properties of the sintered films

2016 ◽  
Vol 12 (1) ◽  
pp. 4141-4144
Author(s):  
Garima Jain
Keyword(s):  
Crystallite Size ◽  
Lattice Constant ◽  
Structural Changes ◽  
Structural Investigation ◽  
Energy Gap ◽  
Lattice Parameter ◽  
Metal Chalcogenides ◽  
Optical Energy Gap ◽  
Tin Telluride ◽  
Physical Quantities

Polycrystalline films of tin telluride were prepared by sintering technique. The structural investigation of the films with different thicknesses enables to determine lattice parameter, crystallite size and strain existing in the films. The XRD traces showed that strain was tensile in nature. The crystallite size increases with thickness while strain decreases. Higher the value of tensile strain, larger is the lattice constant. The optical energy gap shows a descending nature with increasing strain and so with the lattice constant. Such an attempt made to delve into interdependence of basic physical quantities helps to explore the properties of SnTe and utilize it as an alternative to heavy metal chalcogenides in various technological applications.  

scholarly journals Influence of Li2CO3 addition on electrical and magnetic properties of Ni0.6Mg0.4Fe2O4

2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Low Frequency ◽  
Solid State Reaction Method ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Frequency Regime ◽  
Xrd Patterns

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.

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