Synthesis-and-characterization-of-Ni-Zn-ferrite-nanoparticles 2010 Journal-of-Magnetism-and-Magnetic-Materials (original) (raw)
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Structural And Magnetic Properties Of Ni-Zn Ferrite Nanoparticles
2010
Nickel zinc ferrite nanoparticles of the composition NixZn1-xFe2O4 (x = 0.1, 0.3, 0.5) have been synthesized by the chemical co-precipitation method. The samples were characterized by X-ray diffraction, TEM, EPR, DC magnetization and AC susceptibility measurements. The X-ray diffraction patterns confirm the synthesis of single crystalline phase of NixZn1-xFe2O4 (x = 0.1, 0.3, 0.5) nanoparticles. Lattice parameter decreases with the increase in nickel content. The magnetic measurements shows superparamagnetic nature of the samples for x = 0.1 and 0.3 whereas for x = 0.5 the material shows ferromagnetic nature. The saturation magnetization is low and increases with increase in nickel content. The superparamagnetic nature of the samples is supported by the EPR and ac susceptibility measurement studies. The blocking temperature increases with the nickel concentration. The changes in the magnetic properties have been explained by the redistribution of the cations on A and B sites.
Synthesis and characterization of Ni–Zn ferrite nanoparticles
Nickel zinc ferrite nanoparticles NixZn1xFe2O4 (x=0.1, 0.3, 0.5) have been synthesized by a chemical co-precipitation method. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, electron paramagnetic resonance, dc magnetization and ac susceptibility measurements. The X-ray diffraction patterns confirm the synthesis of single crystalline NixZn1xFe2O4 nanoparticles. The lattice parameter decreases with increase in Ni content resulting in a reduction in lattice strain. Similarly crystallite size increases with the concentration of Ni. The magnetic measurements show the superparamagnetic nature of the samples for x=0.1 and 0.3 whereas for x=0.5 the material is ferromagnetic. The saturation magnetization is 23.95 emu/g and increases with increase in Ni content. The superparamagnetic nature of the samples is supported by the EPR and ac susceptibility measurement studies. The blocking temperature increases with Ni concentration. The increase in blocking temperature is explained by the redistribution of the cations on tetrahedral (A) and octahedral (B) sites.
Synthesis and magnetic studies of Ni-Zn ferrite nanoparticles
… of Optoelectronics and …, 2006
Ni-Zn ferrite nanoparticles of the system, Ni 0.65 Zn 0.35 Fe 2 O 4 , were synthesized by a soft chemical approach of coprecipitation method. These nanoparticles were separated into four batches and they were annealed at different temperatures from 200 to 800 o C for improved crystallization. All the samples were then characterized by X-ray diffraction, vibrating sample magnetometer and ferromagnetic resonance spectrometer techniques. The XRD patterns confirm spinel structures while the particle sizes, ranging from 9.9 to 15.7 nm, increase with the increase in heat treating temperature. The magnetization values are extremely small even at 10 kOe fields with vanished hysteresis at lower heat treating temperatures; thus leading close to the superparamagnetic nature. The resonance parameters deduced from the FMR spectra are in support of the magnetisation data.
A series of Ni x Zn 1 À x Fe 2 O 4 (x ¼ 0.5, 0.6 and 0.7) ferrite nanoparticles have been synthesized using a co-precipitation technique, in order to understand the doping effect of nickel on their structural and magnetic properties. XRD and FTIR studies reveal the formation of spinel phase of ferrite samples. Substitution of nickel has promoted the growth of crystallite size (D), resulting the decrease of lattice strain (η). It was also observed that the lattice parameter (a) increases with the increase of Ni 2 þ ion concentration. All particles exhibit superparamagnetism at room temperature. The hyperfine interaction increases with the increase of nickel substitution, which can be assumed to the decrease of core–shell interactions present in the nanoparticles. The Mössbauer studies witness the existence of Fe 3 þ ions and absence of Fe 2 þ ions in the present systems. These superparamagnetic nanoparticles are supposed to be potential candidates for biomedical applications. The results are interpreted in terms of microstructure, cation redistribution and possible core–shell interactions.
Advances in Nanoparticles, 2013
Cubic structured nickel-zinc ferrite nanoparticles (Ni 0.25 Zn 0.75 Fe 2 O 4 ) have been synthesized by thermal treatment method. In this procedure, an aqueous solution containing metal nitrates as precursors, polyvinyl pyrrolidone as a capping agent, and deionized water as a solvent were thoroughly stirred, dried at 353 K for 24 h, and crushed into powder before calcination to remove organic matters and crystallize the particles. The structure and particle size were characterized by X-ray powder diffraction and transmission electron microscopy. The average particle size increased from 7 to 25 nm with increase of calcination temperature from 723 to 873 K respectively. The magnetic properties were determined by vibrating sample magnetometer and electron paramagnetic resonance electron paramagnetic resonance at room temperature. By increasing the calcinations temperatures from 723 to 873 K it showed an increase of the magnetization saturation from 11 to 26 emu/g and the g-factor from 2.0670 to 2.1220. The Fourier transform infrared spectroscopy was used to confirm the presence of metal oxide bands at all temperatures and the removal of organic matters at 873 K.
Structural and Magnetic Characterizations of Coprecipitated Ni–Zn and Mn–Zn Ferrite Nanoparticles
IEEE Transactions on Magnetics, 2006
Two mixed ferrite systems, namely Ni 0 65 Zn 0 35 Fe 2 O 4 (Ni-Zn) and Mn 0 75 Zn 0 18 Fe 2 07 O 4 (Mn-Zn) have been prepared by coprecipitation method, and then the resulting ultrafine powders were heat treated at different temperatures from 200 to 800 C for improved crystallinity and magnetic properties. The samples were characterized by X-ray diffraction, vibrating sample magnetometry, and ferromagnetic resonance spectrometry. As a result of the heat treatment, the average particle size has been found to increase from 9.9 to 15.7 nm for Ni-Zn ferrites and from 2.4 to 10.2 nm for Mn-Zn ferrites, and the corresponding magnetization values have increased from 9.1 to 23 emu/g for Ni-Zn ferrites and from 7.9 to 11.7 emu/g for Mn-Zn ferrites, respectively. The results are discussed in the light of changes in particle size and inversion degree parameter for cationic distribution at nanoscales.
Journal of Applied Physics, 2004
Nickel zinc ferrite nanoparticles (Ni 0.20 Zn 0.44 Fe 2.36 O 4 ) have been produced at room temperature, without calcination, using a reverse micelle process. Particle size is approximately 7 nm as determined by x-ray powder diffraction and transmission electron microscopy. Saturation magnetization values are lower than anticipated, but are explained by elemental analysis, particle size, and cation occupancy within the spinel lattice. Extended x-ray absorption fine structure analysis suggests that a significant amount of Zn 2ϩ , which normally occupies tetrahedral sites, actually resides in octahedral coordination in a zinc-enriched outer layer of the particles. This ''excess'' of diamagnetic Zn can thus contribute to the overall decrease in magnetism. Further, this model can also be used to suggest a formation mechanism in which Zn 2ϩ is incorporated at a later stage in the particle growth process.
Chinese Journal of Chemical Physics, 2008
Ferrites having general formula Ni 1−x ZnxFe 2 O 4 with x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, and 0.7 were prepared by wet chemical co-precipitation method. The structural and magnetic properties were studied by means of X-ray diffraction, magnetization, and AC susceptibility measurements. The X-ray analysis confirmed the single-phase formation of the samples. The lattice parameter obtained from XRD data was found to increase with Zn content x. The cation distribution was studied by X-ray intensity ratio calculations. Magnetization results exhibit collinear ferrimagnetic structure for x≤0.4, and which changes to non-collinear for x >0.4. Curie temperature T C obtained from AC susceptibility data decreases with increasing x.
The calcinations temperature is one of the important process parameter which influences the changes of magnetic properties in ferrites. This study provide better understanding of the influence of calcination temperatures on the magnetic properties of Nickel Zinc ferrite consequently enable to tailor the magnetic properties of Nickel Zinc ferrite for specific application. Magnetic nanoparticles of Nickel Zinc ferritewere synthesized by sol-gel technique. Their crystallite size and the influence of calcinations temperature on magnetic properties were investigated by using X-Ray Diffraction (XRD) and Vibrating Sample Magnetometer (VSM). XRD results showed that the crystallization of the Nickel Zinc ferriteincreased as the calcination temperature increased. The results showed that single phase of Nickel Zinc ferritesamples can be obtained at various calcination temperatures from 800 to 1100°C. All Nickel Zinc ferritesamples exhibited ferrimagnetic behavior. VSM results showed that the saturation magnetization and coercivity values strongly influenced by the calcination temperature.
Synthesis, Structural, Electrical and Magnetic Studies of Ni-Ferrite Nanoparticles
Mono-dispersed NiFe 2 O 4 nanoparticles have been synthesized using a stable ferric salt of FeCl 3 with co-precipitation technique, for study of their structural, morphological and magnetic properties. The XRD pattern conforms the formation of FCC structure with the lattice constant 8.31A o. The crystallite size was found to increase with the bath temperature ranging from 33nm to 55nm. The AFM results revealed that uniform disc shaped particles were obtained. The resistivity measurements show a metal like to semiconductor transition, which depends on the size of the grains. The magnetic study reveals that saturation magnetization increases with the grain thickness.