Properties Of Ni-Zn Ferrites Research Articles

Study of iron ion distribution in rare earth (La, Pr, Sm, Dy) doped nickel-zinc spinel ferrites through Mössbauer spectroscopy

Ni0.5Zn0.5Fe1.95RE0.05O4 (RE=La, Pr, Sm, Dy) spinel ferrites were prepared using the sol-gel method. X-ray diffraction analyses revealed that doping with rare earth ions increases the lattice parameters of the ferrites, accompanied by a decreasing trend due to lanthanide contraction. Mössbauer spectrum showed that rare earth ion doping facilitates the migration of iron ions from B sites to A sites, with the extent of migration increasing alongside the atomic number of the rare earth elements. Vibrating sample magnetometer tests indicated a general decrease in saturation magnetization following rare earth ion doping. A comprehensive investigation into the effects of different rare earth ion dopings on the properties of Ni-Zn ferrites was conducted by calculating theoretical magnetic moments and comparing them with the experimentally measured values. This comparison elucidated the mechanism behind the magnetic alterations in rare earth-doped spinel ferrites, providing theoretical support for future magnetic modulation in these materials.

졸겔법을 통해 합성한 Ni-Zn Ferrite의 구조와 자기적 특성

본 연구에서는 졸겔법으로 NiSUBx/SUBZnSUB1−x/SUBFe₂O₄(x = 0.4, 0.5, 0.6)를 합성하였다. 합성 온도가 400 ℃이상일 때 단상의 spinel 상이 합성되었으며, 온도가 400 ℃에서 1000 ℃로 증가함에 따라 입자 크기도 17.6 nm에서 96.2 nm로 증가하였다. 400 ℃에서 합성한 NiSUBx/SUBZnSUB1−x/SUBFe₂O₄(x = 0.4, 0.5, 0.6) 시료에 대해 1000 ℃ 및 1250 ℃의 온도에서 각각 소결 공정을 진행하였다. 소결체에 대하여 BH curve 및 복소투자율 spectra를 측정하여 Ni 치환량 및 소결 온도에 따른 자기적 특성의 변화를 연구하였다.

The effect of Sb on the electrical and magnetic properties of Ni-Zn ferrites prepared by sol–gel autocombustion method

Polycrystalline Ni-Zn ferrites with a well-defined composition of Ni0.4Zn0.6Fe2-xSbxO4 synthesized using sol- gel method. Morphological characterizations on the prepared samples were performed by high resolution transmission electron and field emission scanning electron microscopy. The powders were densified using microwave sintering method. The room temperature complex permittivity (e' and e") and permeability (μ' and μ") were measured over a wide frequency range from 1 MHz-1.8 GHz. The real part of permittivity varies as 'x' concentration increases and the resonance frequency was observed at much higher frequen- cies and there is a significant decrease in the loss factor (tanδ). The electrical resistivity and permeability of NiZn ferrites increased with an increase of Sb content. As the concentration of 'x' increases from 0 to 0.08 the saturation magnetisation de- creases. The saturation magnetization (Ms)≈52.211 A.m 2 /Kg for x=0 at room temperature. The room temperature electro para- magnetic resonance (EPR) were studied.

Microstructure and Magnetic Properties of Microwave Sintered Ni<sub>0.5</sub>Zn<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub> Ferrite

Ni0.5Zn0.5)Fe2O4 ferrite has been sintered via microwave irradiation. The structural, component and magnetic properties of NiZn ferrite was determined by SEM, X-ray powder diffraction (XRD) and automatic hysteresis loop magnetometer. Results showed that the material sintered by microwave energy at 1220°C for 20min had a high purity (Ni0.5Zn0.5)Fe2O4 phase. The sample obtained magnetic properties of intrinsic coercivity 222A/m, saturation magnetization 332mT, initial permeability 0.20mH/m and maximum permeability 0.58mH/m. Compared with conventional sintering method, microwave sintering of NiZn ferrite is more efficient and reducing soaking time.

Microwave Synthesis and Characterizations of Ni<sub>0.5</sub>Zn<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub> Ferrite Powder

Microwave heating method was used to synthesize (Ni0.5Zn0.5)Fe2O4 ferrite from a stoichiometric mixture of corresponding metal oxides powders. The structural, chemical and magnetic properties of Ni-Zn ferrite was determined by X-ray powder diffraction (XRD) and vibrating sample magnetometry (VSM). Results showed that the material was spinel structure with a high purity with an estimated crystallite size of ∼30nm by X-ray line profile fitting. The sample systhetized by microwave energy at 860°C for 30min has magnetic properties of intrinsic coercivity 55.94G and saturation magnetization 19.43 emu/g. Compared with conventional burning method, microwave systhesis of NiZn ferrite is more efficient and reducing a lots of soaking time.

Contribution to analysis of Cu-substituted NiZn ferrites

Polycrystalline NiZn ferrites with the chemical formula (Ni 0.3Zn 0.7) 1− x Me x Fe 2O 4 where Me is Cu with x=0.05, 0.1 and 0.25 have been prepared by a ceramic method. Certain magnetic properties such as the coercivity H c , initial permeability μ i and saturation magnetisation M s of the ferrites have been measured and discussed from the point of view of the substituting element contents as well as the total pore volume. The Mössbauer spectra of selected samples have been analysed as well. According to the requirement of particular applications, the properties of NiZn ferrite have to be improved by means of proper substitution of selected ions.

Preparation and Properties of Ni-Zn Ferrite by Coprecipitation Method

Ni-Zn ferrite powder was obtained by wet method that was to be coprecipitated the metal nitrates, Fe(<TEX>$NO_3$</TEX>)<TEX>$_3$</TEX>ㆍ<TEX>$9H_2$</TEX>O, Ni(<TEX>$NO_3$</TEX>)<TEX>$_2$</TEX>ㆍ<TEX>$6H_2$</TEX>O, Zn(<TEX>$NO_3$</TEX>)<TEX>$_2$</TEX>ㆍ<TEX>$6H_2$</TEX>O to make a high permeability material. The composition of the ferrite powder was <TEX>$Fe_2$</TEX><TEX>$O_3$</TEX> 52 mol%, NiO 14.4 mol%, ZnO 33.6 mol%. Ni-Zn ferrite powder was compounded by precipitating metal nitrates with NaOH in vessel at the synthetic temperature of <TEX>$90^{\circ}C$</TEX> for 8 hours. Calcination temperature and sintering temperature were <TEX>$700^{\circ}C$</TEX> and <TEX>$1150^{\circ}C$</TEX>～<TEX>$1250^{\circ}C$</TEX>, respectively, for 2 hours. And the other ferrite powder was also prepared by the wet ball milling that was to be mixed the metal oxides as same as the above chemical composition. We studied the properties of the powder and the electromagnetic characteristics of the sintered cores obtained from there two different processes. Wet direct process produced smaller particle size with narrower distribution of the size and more purified ferrite whose sintered cores had high permeability and high magnetization.

Effect of chromium substitutions on some properties of NiZn ferrites

Compositions having the general formula Ni 0.6Zn 0.4Cr t Fe 2- t O 4 with t=0.00, 0.05, 0.10, 0.15, 0.20 and 0.25 were prepared by the usual ceramic processing from high purity oxides. The samples were sintered at 1250 °C in static air atmosphere. X-ray diffraction and IR absorption spectra were used for analysing the composition. Lattice parameter, true density, bulk density, porosity and shrinkage were measured for the samples. A scanning electron microscope investigation was also carried out. It is observed that all samples have a single phase with spinel cubic structure. Lattice parameter, true density, bulk density are found to increase with increasing Cr concentration, whereas both porosity, shrinkage and grain size showed a decreasing trend with the Cr content.

Magnetic properties of Ni-Zn ferrites doped with Ti4+ ions

Magnetic properties of Ni-Zn ferrites doped with Ti4+ ions

The influence of additives on the properties of Ni-Zn ferrite used in magnetic heads

The present paper describes the effect of addition of CaO, Na 2O, ZrO 2, Li 2O, K 2O and Sb 2O 3 on the properties of sintered Ni 0.36Zn 0.64Fe 2O 4 ferrite used in magnetic heads. We found that the density, coercivity, permeability and flux density are affected by additives. The best results from the point of view of magnetic and mechanical characteristics acceptable for magnetic heads were obtained by triple additions: Na 2O-CaO-ZrO 2 and Na 2O-CaO-Li 2O.

Nickel-zinc ferrites with additives for use in magnetic heads

The effect of the addition of Na 2O, CaO and ZrO 2 on the properties of NiZn ferrite, manufactured by the classical method, was studied. Because the porosity, resistivity, permeability and saturation magnetisation are affected, it is possible to select the kind of additive needed to produce NiZn ferrites with electrical and magnetic properties suitable for magnetic heads.

Some physical and technological effects of V 2O 5 or Bi 2O 3 on the properties of Ni-Zn ferrites

The different roles of Bi 2O 3 and V 2O 5 in sintering process of Ni-Zn ferrites are discussed. Experimental results are described that confirm that only Bi 2O 3 behaves in Ni-Zn ferrites as a flux. The practical importance and technological limitations of Bi 2O 3 and V 2O 5 applications as admixtures are considered.