Magnetic loss in soft ferrites

2007 ◽  
Vol 101 (9) ◽  
pp. 09M522 ◽  
Author(s):  
Waseem A. Roshen
Keyword(s):  
Magnetic Loss ◽  
Soft Ferrites

SOFT FERRITES

1985 ◽  
Vol 46 (C6) ◽  
pp. C6-159-C6-167 ◽  
Author(s):  
T. Postupolski
Keyword(s):  
Soft Ferrites

Study of Precise Computation Method of Magnetic Loss Considering Blanking Press Strain

2017 ◽  
Vol 137 (3) ◽  
pp. 254-260 ◽  
Author(s):  
Satoshi Doi ◽  
Tetsuya Aoki ◽  
Keiichi Okazaki ◽  
Yasuhito Takahashi ◽  
Koji Fujiwara
Keyword(s):  
Magnetic Loss ◽  
Computation Method

scholarly journals Interface Engineered Microcellular Magnetic Conductive Polyurethane Nanocomposite Foams for Electromagnetic Interference Shielding

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Guolong Sang ◽  
Pei Xu ◽  
Tong Yan ◽  
Vignesh Murugadoss ◽  
Nithesh Naik ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Magnetic Loss ◽  
Interfacial Polarization ◽  
Conductive Network ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Multiple Reflections ◽  
Conduction Loss ◽  
Composite Foams ◽  
Emi Se

Abstract Lightweight microcellular polyurethane (TPU)/carbon nanotubes (CNTs)/ nickel-coated CNTs (Ni@CNTs)/polymerizable ionic liquid copolymer (PIL) composite foams are prepared by non-solvent induced phase separation (NIPS). CNTs and Ni@CNTs modified by PIL provide more heterogeneous nucleation sites and inhibit the aggregation and combination of microcellular structure. Compared with TPU/CNTs, the TPU/CNTs/PIL and TPU/CNTs/Ni@CNTs/PIL composite foams with smaller microcellular structures have a high electromagnetic interference shielding effectiveness (EMI SE). The evaporate time regulates the microcellular structure, improves the conductive network of composite foams and reduces the microcellular size, which strengthens the multiple reflections of electromagnetic wave. The TPU/10CNTs/10Ni@CNTs/PIL foam exhibits slightly higher SE values (69.9 dB) compared with TPU/20CNTs/PIL foam (53.3 dB). The highest specific EMI SE of TPU/20CNTs/PIL and TPU/10CNTs/10Ni@CNTs/PIL reaches up to 187.2 and 211.5 dB/(g cm−3), respectively. The polarization losses caused by interfacial polarization between TPU substrates and conductive fillers, conduction loss caused by conductive network of fillers and magnetic loss caused by Ni@CNT synergistically attenuate the microwave energy.

Effective Application of Magnetic Material Based on Metamaterial Absorber

2013 ◽  
Vol 774-776 ◽  
pp. 907-912
Author(s):  
Hui Bin Zhang ◽  
Li Wei Deng ◽  
Nan Zhang ◽  
Pei Heng Zhou ◽  
Jian Liang Xie ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Design Method ◽  
Copper Wire ◽  
Wire Array ◽  
Magnetic Loss ◽  
Peak Position ◽  
Metamaterial Absorber ◽  
Absorption Peak ◽  
Perfect Absorption ◽  
Effective Application

We simulate, fabricate and measure a microwave absorber by introducing metamaterial design method to magnetic material. The proposed absorber is composed of periodic copper wire array, magnetic material coated on copper wires, a foam substrate and a bottom metal plane. The results show a nearly perfect absorption peak around 8.7GHz (simulated) and 7.6GHz (measured). Even though the electric and magnetic field distribution indicate that the absorption is a typical metamaterial absorption, the power loss is neither Ohmic nor dielectric loss but magnetic loss, which is different from typical metamaterial absorber. The skillful introduction of the magnetic loss improves the absorption performance, including the absorption bandwidth and intensity. The designed absorber shows an effective application of the magnetic material, which is only 1/60000 volume proportion of the total absorber. Dependences of the absorption on frequency and the coating volume of the magnetic material manifest that the coated magnetic material can adjust the absorption peak position and intensity. The absorber can be an attractive candidate of electromagnetic wave absorber.

Soft-ferrites, achievements and problems

1980 ◽  
Vol 19 (1-3) ◽  
pp. 88-96 ◽  
Author(s):  
Svatopluk Krupička
Keyword(s):  
Soft Ferrites

Application of Nanocrystalline Magnetic Materials in Electromechanical Devices

2011 ◽  
Vol 694 ◽  
pp. 341-344
Author(s):  
Li Jun Wang ◽  
Jie Qiong Li ◽  
Hong Jing Wang
Keyword(s):  
Magnetic Materials ◽  
Nanocrystalline Materials ◽  
Magnetic Loss ◽  
Electronic Devices ◽  
Silicon Steel ◽  
Surveillance Systems ◽  
Flux Reversal ◽  
Telecommunication Equipment ◽  
Electromechanical Devices ◽  
Property Modification

Application of nanocrystalline magnetic materials in electromechanical devices is increasingly being adopted, helping to solve energy-saving problems and global warming. Compared with conventional silicon steel materials, nanocrystalline materials show faster flux reversal, lower magnetic loss and more versatile property modification, which result in the successful application in modern electronic devices. Nanocrystalline magnetic materials will be increasingly popularized and used in power electronics, telecommunication equipment and electronic article surveillance systems due to the demands for smaller and efficient devices in the future.

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.

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