scholarly journals Enhanced Magnetization of Sol-Gel Synthesized Pb-Doped Strontium Hexaferrites Nanocrystallites at Low Temperature

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Shahid M. Ramay ◽  
Shahid Atiq ◽  
Murtaza Saleem ◽  
Asif Mahmood ◽  
Saadat A. Siddiqi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Saturation Magnetization ◽  
Structural Parameters ◽  
Hexagonal Phase ◽  
Magnetic Moments ◽  
Sol Gel ◽  
Magnetic Characteristics ◽  
Energy Product ◽  
Pb Substitution

Effect of Pb doping on the structural and low temperature magnetic properties ofSrPbxFe12-xO19(x=0,0.1,0.2,0.3,and  0.4), synthesized by sol-gel autocombustion technique, has been investigated. The powder samples were sintered at 800°C for 2 h in order to develop the stable hexagonal phase, characteristic of the SrFe12O19structure. The consequences of Pb substitution (at iron sites) on various structural parameters like lattice constants, unit cell volume, crystallite size, and porosity have been discussed. Fourier transform infrared frequency bands were utilized to determine the formation of tetrahedral and octahedral clusters of M-type ferrites. Hexagonal texture of the grains, a characteristic of the hexagonal crystal structure of SrFe12O19, was refined by Pb substitution. The magnetic properties, determined using a vibrating sample magnetometer, revealed that saturation magnetization decreased, while coercivity was increased with the increase of Pb contents. However, the increased squareness ratio and hence the energy product motivate the utilization of these ferrite compositions where hard magnetic characteristics are required. The increased values of saturation magnetization were observed at reduced temperature of 200 K, attributable to the better spin alignments of individual magnetic moments at low temperature.

scholarly journals Magnetic properties of hexaferrite nanosized powders produced via mechanoactivation

2005 ◽  
Vol 37 (2) ◽  
pp. 107-114 ◽  
Author(s):  
E.P. Naiden ◽  
R.A. Zhuravlyov ◽  
V.I. Itin ◽  
O.G. Terekhova ◽  
M.V. Politov ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Saturation Magnetization ◽  
Size Effects ◽  
Magnetic Phase ◽  
Structural Parameters ◽  
Magnetic Characteristics ◽  
Nanosized Powders ◽  
Similar Materials ◽  
The Relationship

A study of the relationship between structural parameters and principal magnetic characteristics of nanosized powders of hexagonal ferrimagnetics produced via mechanoactivation has been carried out. The models describing the influence of the size effects on temperatures of magnetic phase transformations, saturation magnetization and magnetic anisotropy of similar materials are discussed.

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Rare Earth Ions ◽  
Ion Concentration ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Combustion Technique

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.

MAGNETIC PROPERTIES OF U1-xDyxAlyNi5-y (y=0,1) SYSTEMS

2003 ◽  
Vol 17 (27n28) ◽  
pp. 1453-1460
Author(s):  
ILEANA LUPSA
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Spin Fluctuation ◽  
Magnetic Moments ◽  
Transition Temperatures ◽  
Temperature Range ◽  
Fluctuation Model ◽  
Magnetically Ordered

The magnetic properties of U 1-x Dy x Al y Ni 5-y (y=0,1) systems were investigated in the 2(5)–600 K temperature range and for fields up to 80 kOe. The systems having x≥0.2 are magnetically ordered with low transition temperatures and magnetization mainly due to the Dy contribution. The nickel exhibits magnetic moments, very weak in the low temperature range and well-defined effective moments over transition temperatures. The nickel behavior is discussed in terms of the spin fluctuation model.

Mechanochemical Synthesis of Hexagonal Ferrites BaFe12O19

2018 ◽  
Vol 781 ◽  
pp. 119-124 ◽  
Author(s):  
Viktor Zhuravlev ◽  
Anna Nevmyvaka ◽  
Volya Itin ◽  
Dmitry Velikanov
Keyword(s):  
Phase Composition ◽  
Saturation Magnetization ◽  
Mechanochemical Synthesis ◽  
Annealing Temperature ◽  
Structural Parameters ◽  
Anisotropy Field ◽  
Magnetic Characteristics ◽  
Hexagonal Ferrites ◽  
Increasing Temperature ◽  
Synthesized Materials

The phase composition, structural parameters, and basic magnetic characteristics of BaFe12O19 hexaferrites prepared by the mechanochemical synthesis with subsequent annealing at a temperature of 1000°С and 1100°С for 1 h are investigated. The influence of the annealing temperature on the properties of synthesized materials is analyzed. Values of the saturation magnetization and the anisotropy field are determined. It is established that annealing temperature in the interval 1000 - 1100 °C does not significantly affect on the phase composition and the size of nanoparticles. The value of the anisotropy field increases substantially with increasing temperature.

scholarly journals Effect of the electrodeposition potential on the magnetic properties of FeCoNi films

2019 ◽  
Vol 37 (3) ◽  
pp. 389-394
Author(s):  
Setia Budi ◽  
Sukro Muhab ◽  
Agung Purwanto ◽  
Budhy Kurniawan ◽  
Azwar Manaf
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Sulfate Solution ◽  
Synthesis Process ◽  
Magnetic Characteristics ◽  
Soft Magnetic ◽  
X Ray ◽  
Ni Content ◽  
The Mean ◽  
Feconi Alloy

AbstractThe effect of electrodeposition potential on the magnetic properties of the FeCoNi films has been reported in this paper. The FeCoNi electrodeposition was carried out from sulfate solution using potentiostatic technique. The obtained FeCoNi films were characterized by X-ray diffractometer (XRD), atomic absorption spectrometer (AAS) and vibrating sample magnetometer (VSM). It has been shown that the electrodeposition potential applied during the synthesis process determines the magnetic characteristics of FeCoNi films. The more negative potential is applied, the higher Ni content is in the FeCoNi alloy. At the same time, Co and Fe showed almost similar trend in which the content decreased with an increase in applied potential. The mean crystallite size of FeCoNi films was ranging from 11 nm to 15 nm. VSM evaluation indicated that the FeCoNi film is a ferromagnetic alloy with magnetic anisotropy. The high saturation magnetization of FeCoNi film was ranging from 86 A·m2/kg to 105 A·m2/kg. The film is a soft magnetic material which was revealed by a very low coercivity value in the range of 1.3 kA/m to 3.7 kA/m. Both the saturation magnetization and coercivity values decreased at a more negative electrodeposition potential.

scholarly journals LOW-TEMPERATURE SYNTHESIS OF SUPERPARAMAGNETIC Zn0.8Ni0.2Fe2O4 FERRITE NANOPARTICLES

2018 ◽  
Vol 56 (1) ◽  
pp. 31
Author(s):  
Luong Thi Quynh Anh ◽  
Nguyen Van Dan ◽  
Do Minh Nghiep
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Oleic Acid ◽  
Low Temperature ◽  
Coercive Force ◽  
Saturation Magnetization ◽  
Ferrite Nanoparticles ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Co Precipitation

The crystalline nanoparticles of Ni0.2Zn0.8Fe2O4 ferrite were synthesized by chemical co-precipitation with precursor concentration of 0.1M, then modified by 0.25M solution of oleic acid in pentanol, finally heated at temperatures 120, 140, 160 and 180oC for 6h in autoclave. The XRD, EDS and TEM confirmed that all of samples are crystalline and their particle size are 6, 6.5, 7 and 8 nm. The magnetic properties showed that the coercive force, the remanence of samples are about zero, the saturation magnetization Ms has values from 14.20 to 27.12 emu/g.

Structural, morphological and magnetic properties of Mn2+ ions substituted nanosized nickel–copper–cobalt ferrites through sol–gel auto-combustion method

2019 ◽  
Vol 34 (01) ◽  
pp. 2050002
Author(s):  
Wei Zhang ◽  
Aimin Sun ◽  
Xiqian Zhao ◽  
Xiaoguang Pan ◽  
Yingqiang Han
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Spinel Structure ◽  
Remanent Magnetization ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Combustion Method ◽  
Magnetic Data ◽  
Nickel Copper ◽  
Auto Combustion

Manganese substituted nickel–copper–cobalt ferrite nanoparticles having the basic composition [Formula: see text] (x = 0.0, 0.1, 0.2, 0.3 and 0.4) were synthesized by sol–gel auto-combustion method. X-ray diffraction (XRD) was used to estimate phase purity and lattice symmetry. All the prepared samples show the single-phase cubic spinel structure. Fourier transform infrared (FTIR) measurements also confirm the cubic spinel structure of the ferrite that is formed. The preparation of samples show these nearly spherical particles by Transmission electron microscopy (TEM). The magnetic properties of Mn[Formula: see text] ion substituted in nickel–copper–cobalt ferrite were studied by Vibrating sample magnetometer (VSM). The saturation magnetization ([Formula: see text]), remanent magnetization [Formula: see text], coercivity [Formula: see text], magnetic moment [Formula: see text] and anisotropy constant [Formula: see text] first increase and then decrease with the increase of [Formula: see text] ions content. They had better magnetism than pure sample and other substituted samples when the substitution amount of [Formula: see text] ions was [Formula: see text]. At [Formula: see text], the maximum values of remanent magnetization [Formula: see text], saturation magnetization [Formula: see text] and coercivity [Formula: see text] are 25.58 emu/g, 61.95 emu/g and 689.76 Oe, respectively. This indicates that the magnetism of ferrite can improve by substituting with the appropriate amount of manganese. However, due to the excess [Formula: see text] ions instead, ferrite magnetism is weakened. This means that these materials can be used in magnetic data storage and recording media.

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.

Effects of Na-Doping on Structure and Magnetic Properties of LaCoO3

2017 ◽  
Vol 727 ◽  
pp. 403-409
Author(s):  
Yi Hao Shen ◽  
Qing Rong Yao ◽  
Peng Cheng Yang ◽  
Jian Qiu Deng ◽  
Zong Min Wang
Keyword(s):  
Magnetic Properties ◽  
Structure Refinement ◽  
Hexagonal Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Zero Field ◽  
Ferromagnetic Transition ◽  
Na Doping ◽  
Crystallite Sizes ◽  
Field Cooling

Effect of Na doping on the structural and magnetic properties of La1-xNaxCoO3 (0≤x≤0.4) nanopowder samples synthesized by sol-gel method have been investigated. Rietveld crystal structure refinement of the X-ray diffraction data shows that La1−xNaxCoO3 (x≤0.3) crystallizes in the rhombohedral structure with space group . The lattice parameters decrease and the crystallite sizes increase with the increase of x. For the sample with x=0.4, a secondary hexagonal phase NaCo2O4 was observed. The zero field cooling (ZFC) and field cooling (FC) curve of the samples (x≤0.3) exhibit a paramagnetic-ferromagnetic transition with decreasing temperature.

MAGNETIC PROPERTIES OF Ni NANOPARTICLES

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4390-4394 ◽  
Author(s):  
Y. T. JEON ◽  
J. Y. MOON ◽  
G. H. LEE ◽  
J. PARK
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Magnetic Moments ◽  
Particle Diameter ◽  
Average Particle ◽  
Ni Nanoparticles ◽  
Size Dependent

We investigated the size dependent magnetic properties of Ni nanoparticles. We prepared four samples with average particle diameters of 7.0, 14.0, 16.5, and 20.0 nm. The blocking temperatures (TBs) were 40.0, 150.0, 250.0, and ~ 300.0 K for the above Ni nanoparticles, respectively. Saturation magnetization increased with increasing particle diameter due to the reduced magnetic moments of surface atoms. The coercivities at 5 K ranged from 270 and 340 Oe, whereas those at 300 K were zero due to superparamagnetism.

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