Magnetic Properties of Ni-Zn Ferrite Ceramics Prepared from the Blend of Powders

2005 ◽  
Vol 475-479 ◽  
pp. 2193-2196 ◽  
Author(s):  
Haisheng Zhong ◽  
Qiang Li ◽  
Zhifeng Zhong ◽  
Ming Cheng
Keyword(s):  
Magnetic Properties ◽  
Grain Growth ◽  
Fine Particles ◽  
Sintering Temperature ◽  
Initial Permeability ◽  
Abnormal Grain Growth ◽  
Zn Ferrite ◽  
Low Sintering Temperature ◽  
Ultra Fine Particles

Ni-Zn ferrite ceramics were prepared from the blend of nano-sized powders and ultra-fine particles at the relative low sintering temperature (≤1200°C). The microstructure of the as-sintered samples characterized by SEM indicated that this process obstructed abnormal grain growth which often appeared in the Ni-Zn ferrite ceramics sintered from the nano-sized powders. The result of VSM measurements showed that the ratio of nano-sized powders to ultra-fine particles effected the initial permeability (μi) of the as-sintered samples. Optimum initial permeability can be obtained by adjusting the ratio as 1:1.

EFFECT OF COPPER OXIDE ON THE GRAIN GROWTH AND INITIAL PERMEABILITY OF Mg–Cu–Zn FERRITES

2010 ◽  
Vol 24 (02) ◽  
pp. 169-182
Author(s):  
M. MANJURUL HAQUE ◽  
M. HUQ ◽  
SYED FARID UDDIN FARHAD ◽  
JASIM UDDIN KHAN ◽  
M. A. HAKIM
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Grain Growth ◽  
Spinel Phase ◽  
Initial Permeability ◽  
Cu Content ◽  
Average Grain Size ◽  
Zn Ferrite ◽  
Effect Of Copper ◽  
Microstructure And Magnetic Properties

The microstructure and magnetic properties of Mg – Cu – Zn ferrites prepared by using solid-state reaction method have been investigated. X-ray diffraction (XRD), a scanning electron microscope (SEM), impedance analyzer and a vibrating sample magnetometer (VSM) were utilized in order to study the effect of copper substitution and its impact on the crystal structure, grain size, microstructure and magnetic properties of the Mg – Cu – Zn ferrite. The formation of cubic spinel phase was identified using XRD technique. The microstructures of the samples show that the grain growth is greatly enhanced by the addition of CuO which is attributed to the liquid phase during sintering. The average grain size (Dm) increases significantly with increasing Cu content. The initial permeability (μ') of the samples increases appreciably with increasing Cu content which is attributed to the increase of grain size and density of the samples. The resonance frequency (fr) of the samples shifts toward the lower frequency as the Cu content increases. The sharp fall of μ' in μ'-T curves is observed for all the samples which indicate the homogeneity of the samples. The saturation magnetization (Ms) of the Mg – Cu – Zn ferrites increases slightly with increasing Cu concentration.

scholarly journals Analysis of grain growth, structural and magnetic properties of Li-Ni-Zn ferrite under the influence of sintering temperature

Heliyon ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. e01199
Author(s):  
M.A. Islam ◽  
M. Zahidur Rahaman ◽  
Md. Mehedi Hasan ◽  
A.K.M. Akther Hossain
Keyword(s):  
Magnetic Properties ◽  
Grain Growth ◽  
Sintering Temperature ◽  
Zn Ferrite ◽  
Structural And Magnetic Properties

Magnetodielectric Ni ferrite ceramics with Bi2O3 additive for potential antenna miniaturizations

2009 ◽  
Vol 24 (2) ◽  
pp. 324-332 ◽  
Author(s):  
X.T. Liew ◽  
K.C. Chan ◽  
L.B. Kong
Keyword(s):  
Magnetic Properties ◽  
Dielectric Loss ◽  
Grain Growth ◽  
Sintering Temperature ◽  
Magnetic Loss ◽  
Liquid Phase Sintering ◽  
X Ray Diffraction ◽  
Low Dielectric ◽  
High Concentrations

This paper reports on the preparation and characterization of nickel ferrite (NiFe1.98O4) ceramics doped with Bi2O3 as sintering aid. Focus has been on the effects of concentration of Bi2O3 and sintering temperature on the densification, grain growth, dielectric, and magnetic properties of the NiFe1.98O4 ceramics, with an aim at developing magnetodielectric properties, with almost equal real permeability and permittivity, as well as sufficiently low magnetic and dielectric loss tangents, over 3 to 30 MHz (high frequency or HF band). X-ray diffraction results indicated that there is no obvious reaction between NiFe1.98O4 and Bi2O3, at Bi2O3 levels of up to 7 wt% and temperatures up to 1150 °C. The addition of Bi2O3 facilitated a liquid phase sintering mechanism for the densification of NiFe1.98O4 ceramics. The addition of Bi2O3 not only improved the densification but also promoted the grain growth of NiFe1.98O4 ceramics. To achieve sufficiently low dielectric loss tangent, the concentration of Bi2O3 should not be less than 5 wt%. The low dielectric loss tangents of the samples doped with high concentrations of Bi2O3 can be attributed to the full densification of the ceramics. Magnetic properties of the NiFe1.98O4 ceramics, as a function of sintering temperature and Bi2O3 concentration, can be qualitatively explained by the Globus model. Promising magnetodielectric properties have been obtained in the sample doped with 5% Bi2O3 and sintered at 1050 °C for 2 h. The sample has almost equal values of permeability and permittivity of ∼12, together with low dielectric and magnetic loss tangents, over 3 to 30 MHz. This material might be useful for the miniaturization of HF (3 to 30 MHz) antennas.

scholarly journals In Search of Magnetic Properties of Samarium Cobalt (Sm2Co17) within a Low-Temperature Sintering Process

2021 ◽  
Vol 16 (3) ◽  
pp. 517-524
Author(s):  
Poppy Puspitasari ◽  
A. Muhammad ◽  
A. A. Permanasari ◽  
T. Pasang ◽  
S. M. S. N. S. Zahari ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Magnetic Properties ◽  
Low Temperature ◽  
Functional Groups ◽  
Sintering Temperature ◽  
Alkyl Halides ◽  
High Coercivity ◽  
Low Temperature Sintering ◽  
Magnetic Anisotropy Energy ◽  
Low Sintering Temperature

Samarium cobalt is known as super high density magnetic material with large magnetic anisotropy energy. Samarium–cobalt exhibits manipulative magnetic properties as a rare-earth material which has different properties in a low sintering temperature. It is therefore of paramount importance to investigate samarium cobalt (Sm2Co17) magnetic properties in the low temperature sintering condition. Sm2Co17, which is utilized in this research, is synthesized via the sol–gel process at sintering temperatures of 400, 500, and 600 °C. Subsequently, the crystallites indicate the formation of a single-phase Sm2Co17 on all the samples in all temperature variations. Moreover, the peaks in the X-ray diffraction analysis of crystallite sizes calculated using the Scherrer equation are 17.730, 15.197, and 13.296 nm at 400, 500, and 600 °C. Through scanning electron microscopy, the particles are found to be relatively large and agglomerated, with average sizes of 143.65, 168.78, and 237.26 nm. The functional groups are also analyzed via Fourier-transform infrared spectroscopy, which results in the appearance of several bonds in the samples, for example, alkyl halides, alkanes, and esters with aromatic functional groups on the fingerprint area and alkynes, alkyl halides, and alcohol functional groups at a wavelength of above 1500 cm. The test results of the magnetic properties using vibrating-sample magnetometer (VSM) revealed high coercivity and retentivity in the samples sintered at 400 °C. However, the highest saturation occurs in the samples sintered at 600 ℃. At a low sintering temperature (below 1000 °C), samarium cobalt shows as the soft magnetic material. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Densification and magnetic properties of NiCuZn low-sintering temperature ferrites with Bi2O3-Nb2O5 composite additives

2019 ◽  
Vol 776 ◽  
pp. 954-959 ◽  
Author(s):  
Fang Xu ◽  
Dainan Zhang ◽  
Gang Wang ◽  
Huaiwu Zhang ◽  
Yan Yang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Sintering Temperature ◽  
Low Sintering Temperature

Effects of oxidation and abnormal grain growth on the magnetic properties of thin Fe–SiO2 granular films

1999 ◽  
Vol 85 (8) ◽  
pp. 6151-6153 ◽  
Author(s):  
J. N. Zhou ◽  
A. Butera ◽  
H. Jiang ◽  
D. H. Yang ◽  
J. A. Barnard
Keyword(s):  
Magnetic Properties ◽  
Grain Growth ◽  
Abnormal Grain Growth ◽  
Granular Films

MAGNETIC PROPERTIES OF SINTERED Nd-Fe-B TYPE MAGNETS CONTAINING CALCIUM, CHLORINE AND CARBON

1992 ◽  
Vol 06 (19) ◽  
pp. 1197-1203 ◽  
Author(s):  
S. SZYMURA ◽  
H. BALA ◽  
YU. M. RABINOVICH ◽  
J. J. WYSLOCKI
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Grain Growth ◽  
Abnormal Grain Growth ◽  
Rich Phase ◽  
Microstructure And Magnetic Properties

The microstructure and magnetic properties of Nd 16-x X x Fe 70.5 Co 5 AlB 7.5 and Nd 14-x Dy 2 X x Fe 71 Co 5 B 8 ( X = Ca , Cl and C ) magnets with various x were examined. In magnets after sintering and heat treatment carbon-rich areas were produced within the non-magnets Nd -rich phase. However chlorine-rich and calcium-rich areas were present in both non-magnetic Nd -rich and B -rich phases. The contribution of C ≤0.35 at%, Cl ≤0.013 at% and Ca ≤0.09 at% had no influence on the magnetic properties (B r and i H c ), but higher concentration of these elements caused decrease in these properties. Abnormal grain growth was found in magnets containing Cl .

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