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| 1 | Preparation and Sinterability of Mn-Zn Ferrite Powders by Sol-Gel Method显示文摘Mn-Zn spinel ferrites were synthesized by sol-gel method. Effects of calcined temperature on structure and particle size of MnZnFe2O4 were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD patterns indicate that the ultra fine Mn-Zn ferrite exhibits a spinel crystal structure. SEM images show that the powder fired at 900 ℃ for 2 h has an average diameter of 60~90 nm. The particle size becomes larger with the increasing of calcined temperature and the distribution of particle becomes even more homogeneous. Sintering behaviors of synthesized ferrite powders depend on the powder characteristics and high temperatures have induced the good crystallization of particles. | 董丽敏 韩志东 张耀明 吴泽 张显友 | 2006 | Journal of Rare Earths2006，24，z2： | 6 |
| 2 | A novel magnetic silica supported spinel ferrites NiFe2O4 catalyst for heterogeneous Fenton-like oxidation of rhodamine B显示文摘A series of spinel fe rrites magnetic nanopa rticles NiFe2 O4 we re synthesized as the heterogeneous Fentonlike catalyst by hydrothermal method and then NiFe2 O4@SiO2 catalysts were obtained by the modification of NiFe2 O4 via micro emulsion method.XRD,VSM,FTIR,SEM,TEM,BET and XPS were carried to analyze the difference between the above two catalysts.NiFe2 O4@SiO2 catalyst exhibited the higher catalytic activity than NiFe2 O4 for the degradation of Rhodamine B owe to the outer Si02 layers surface,the more important is both of them showed the better catalytic performance when at neutral pH environment. | Jifeng Qu Tinghua Che Libin Shi Qinghua Lu Suitao Qi | 2019 | Chinese Chemical Letters2019，30，6： | 3 |
| 3 | Synthesis of hexagonal barium ferrite nanoparticle by sol-gel method显示文摘M-type Ba hexaferrites were successfully synthesized by sol-gel method. Several synthesizing factors, such as pH value, citric acid/metal ion ratio, and dispersion agent were mainly discussed. Fine and pure powders of BaFe12O19 were optimally synthesized under the conditions of the pH value is 7 and citric acid/metal ion ratio is 3. The X-ray diffraction analysis demonstrates that no impurity is observed in the synthesized powders after presintered at 450 ℃ and calcinated at 1100 ℃. SEM observations indicate that the size of the synthesized BaFe12O19 powders is small and uniform distribution. It can also be learned from SEM that the co-synthesizing sol-gel method can be in favor of the formation of finer particles. | DONG Limin HAN Zhidong ZHANG Yaoming WU Ze ZHANG Xianyou | 2006 | Rare Metals2006，25，z1： | 2 |
| 4 | Magnetic properties and microstructures of SnO_2 doped Mn-Zn ferrites显示文摘The effects of additive SnO2 (0.4wt.%), with and without SiO2 (0.02wt.%) and/or CaO (0.04wt.%), on the microstructure and magnetic properties of Mn-Zn ferrites were reported. The results reveal that SnO2 on its own increases the initial permeability (μi) slightly, but SnO2 with SiO2 and/or CaO decreases the values of μi. However, ferrites with SnO2 additions have reduced power losses. The separate contributions of hysteresis loss and eddy current loss to the total power loss show that SnO2 (with or without SiO2 and/or CaO) doping increases the hysteresis loss slightly, but SnO2 doping alone reduces the eddy current loss significantly (~14%). The additions of SiO2 or CaO further decrease the eddy current loss, and by interaction of SnO2-CaO-SiO2, the eddy current loss is reduced by more than 20%. These magnetic and microstructural effects were discussed in terms of the additive-impurity interaction, the existence of grain boundary phases, and the effective bulk and grain boundary resistivities of the ferrites. | NG Foong-Kee SALE Frank R. | 2006 | Rare Metals2006，25，z1： | 1 |
| 5 | Effects of bismuth on structural and dielectric properties of cobalt-cadmium spinel ferrites fabricated via micro-emulsion route显示文摘Spinel ferrites have a significant role in high-tech applications.In the present work nano-crystalline ferrites having general formula Co0.5Cd0.5BixFe2-xO4 with(x=0.0,0.05,0.1,0.15,0.2,and 0.25)are synthesized via micro-emulsion route.Powder x-ray diffraction(XRD)studies discover the FCC spinel structure.Crystalline size is calculated in a range of 11 nm-15 nm.Lattice parameter calculations are reduced due to its substitution which leads to the exchange of large ionic radius of Fe^3+for small ionic radius of Bi^3+.The x-ray density is analyzed to increase with doping.Fourier transform infrared spectroscopy(FTIR)is performed to analyze absorption band spectra.The two absorption bands are observed in a range of 400 cm^-1-600 cm^-1,and they are the characteristic feature of spinel structure.Thermo-gravimetric analysis(TGA)reveals the total weight loss of nearly 1.98%.Dielectric analysis is carried out by impedance analyzer in a frequency span from 1 MHz to 3 GHz by using the Maxwell Wagner model.Dielectric studies reveal the decrease of dielectric parameters.The alternating current(AC)conductivity exhibits a plane behavior in a low frequency range and it increases with the applied frequency increasing.This is attributed to the grain effects in a high frequency range or may be due to the reduction of porosity.Real and imaginary part of impedance show the decreasing trend which corresponds to the grain boundary action.The imaginary modulus shows the occurrence of peak that helps to understand the interfacial polarization.Cole-Cole graph shows a single semicircle which confirms that the conduction mechanism is due to the grain boundaries at low frequency.Dielectric studies reveal the applicability of these ferrites in high frequency equipment,microwave applications,high storage media,and semiconductor devices. | Furhaj Ahmed Sheikh Muhammad Khalid Muhammad Shahzad Shifa H M Noor ul Huda Khan Asghar Sameen Aslam Ayesha Perveen Jalil ur Rehman Muhammad Azhar Khan Zaheer Abbas Gilani | 2019 | Chinese Physics B2019，28，8： | 1 |
| 6 | Computational study of inverse ferrite spinels显示文摘The magnetic properties of inverse ferrite Fe_(3+) Fe_(3+)Co_(2+) O^(2-)_4, Fe^(3+) Fe^(3+)Cu^(2+) O^2_(-4), Fe^(3+) Fe^(3+)Fe^(2+) O^2_(-4),and Fe^(3+) Fe^(3+)Ni^(2+) O^(2-)_4spinels have been studied using Monte Carlo simulation. We have also calculated the critical and Curie Weiss temperatures from the thermal magnetizations and inverse of magnetic susceptibilities for each system.Magnetic hysteresis cycles have been found for the four systems. Finally, we found the critical exponents associated with magnetization, magnetic susceptibility, and external magnetic field. Our results of critical and Curie Weiss temperatures are similar to those obtained by experiment results. The critical exponents are similar to those of known 3 D-Ising model. | A EL Maazouzi R Masrour A Jabar M Hamedoun | 2019 | Chinese Physics B2019，28，5： | 1 |
| 7 | Microstructural,magnetic and dielectric performance of rare earth ion(Sm^(3+))-doped MgCd ferrites显示文摘The combined effects of Sm^(3+)substitution together with the addition of 3 wt%Bi_(2)O_(3)endow Mg Cd ferrites with excellent magnetic permeability and dielectric permittivity.Various concentrations of Sm^(3+)(x=0,0.03,0.06,0.09,0.12and 0.15)were employed to modify the permeability(μ)and permittivity(ε)of the Mg Cd ferrites.X-ray diffraction,scanning electron microscopy(SEM),vibrating sample magnetometry and vector network analysis techniques were used to characterize the samples.The measurement results reveal that the ferrites processed a saturation magnetization of up to 36.8 emu/g and coercivity of up to 29.2 Oe via the conventional solid-state reaction method.The surface morphology SEM confirms that with increasing Sm^(3+)concentration,the grain shape changes from a polygon to a circle.Moreover,the dielectric permittivity can reach a value of 23.The excellent properties obtained in Sm^(3+)-substituted Mg ferrites suggest that they could be promising candidates for modern high-frequency antenna substrates or multilayer devices. | 文丹丹 陈霞 骆大森 卢毅 陈一鑫 黎人溥 崔巍 | 2022 | Chinese Physics B2022，31，7： | 0 |
| 8 | Hysteresis loss free soft magnetic ferrites based on Larmor precession显示文摘A big enough transverse magnetic field applied to soft magnetic ferrite toroid can magnetize the ferrite to a saturation level in transverse direction and almost completely suppresses magnetic domain structures in the ferrite,the response to the longitudinal alternating electromagnetic field changes from the original domain wall displacements and spin rotations to the precession of magnetization around the transverse field,and the hysteresis loss disappears in the ferrites.Both theoretical and experimental results indicate that the permeability and magnetic loss in the ferrite can be controlled by adjusting the transverse magnetic field.A higher Q value with relatively low permeability can be achieved by increasing the transverse field,which ensures that the ferrite can be operated at high frequencies,with magnetic loss being very low. | 冯双久 赵幸丽 朱守金 吕庆荣 阚绪材 刘先松 | 2023 | Chinese Physics B2023，32，8： | 0 |
| 9 | Enhanced electromagnetic absorption in ferrite and tantalum pentoxide based polypyrrole nanocomposite显示文摘The electromagnetic interference(EMI) shielding properties of polypyrrole/barium ferrite/tantalum pentoxide nanocomposite were studied in the X-band frequency range from 8.2 GHz to 12.4 GHz. The nanocomposites were chemically synthesized at room temperature and then characterized by various techniques. The dielectric material parameters were calculated based on the experimental scattering parameters using Nicholson–Ross and Weir algorithms. The synthesized nanocomposites demonstrated that the shielding effectiveness up to 50 dB depended upon the dielectric loss and weight fraction of ferrite and Ta2O5 in the polymer matrix. | Preeti Gairola L.P.Purohit S.P.Gairola Preetam Bhardwaj Shivani Kaushik | 2019 | Progress in Natural Science:Materials International2019，29，2： | 0 |
| 10 | Low loss Z-type Hexaferrites with Bi2O3 Additives for Ultra-high Frequency Antenna Applications显示文摘The Z-type ferrites of nominal composition Ba3Co2 Fe24O41+x wt% Bi2O3, where x=0.25, 0.5, 1.0, 1.5, 2.0, were prepared by conventional ceramic processes. The influence of Bi2O3 content on the bulk densities, microstructures, magnetic and dielectric properties of Z-type ferrite samples were systematically examined so as to obtain materials with low magnetic and dielectric loss tangent over a frequency ranging from 600 to 800 MHz. The experimental results showed that addition of Bi2O3 lowered the sintering temperature(1 020 ℃) and then reduced the average grain size(<2 μm) and enhanced the resistivity(>2.68×10^8 Ω·cm) dramatically, which consequently decreased the magnetic and dielectric loss. Additionally, the low loss factors were observed at the Bi2O3 content x = 1.0, i e, tan δμ/μ’=0.013 and tan δε/ε’= 0.001 at 800 MHz, and such materials could be used for antennas miniaturization from 600 to 800 MHz. | 郭永强 WANG Shizhang 聂彦 | 2019 | Journal of Wuhan University of Technology(Materials Science)2019，34，5： | 0 |
| 11 | Effect of sintering temperature on structural,magnetic,dielectric and optical properties of Ni-Mn-Zn ferrites显示文摘Spinel ferrite Ni_(0.08)Mn_(0.90)Zn_(0.02)Fe_(2)O_(4)was prepared by a conventional ceramic process followed by sintering at three different temperatures(1050°C,1100°C and 1150°C).X-ray diffraction(XRD)investigations stated the single-phase cubic spinel structure and the FTIR spectra revealed two prominent bands within the wavenumber region from 600 cm^(−1)to 400 cm^(−1).Surface morphol-ogy showed highly crystalline grain development with sizes ranging from 0.27μm to 0.88μm.The magnetic hysteresis curve at ambient temperature revealed a significant effect of sintering temperature on both coercivity(Hc)and saturation magnetization(Ms).Temperature caused a decrease in DC electrical resistivity,while the electron transport increased,suggesting the semicon-ducting nature of all samples and that they well followed the Arrhenius law from which their activation energies were determined.The values of Curie temperature(Tc)and activation energy were influenced by the sintering temperature.Frequency-dependent dielectric behavior(100 Hz-1 MHz)was also analyzed,which may be interpreted by the Maxwell-Wagner-type polarization.The UV-vis-NIR reflectance curve was analyzed to calculate the bandgap of ferrites,which showed a decreasing trend with increasing sintering temperature. | Nazia Khatun Mohammad Sajjad Hossain MostHosney Ara Begum Suravi Islam Nazmul Islam Tanvir Riyadh Hossen Bhuiyan Md.Al-Mamun | 2021 | Journal of Advanced Dielectrics2021，11，6： | 0 |
| 12 | A New Fuzzy Controlled Antenna Network Proposal for Small Satellite Applications显示文摘This research contributes to small satellite system development based on electromagnetic modeling and an integrated meta-materials antenna networks design for multimedia transmission contents.It includes an adaptive nonsingular mode tracking control design for small satellites systems using fuzzy waveless antenna networks.By analyzing and modeling based on electromagnetic methods,propagation properties of guided waves from metallic structures with simple or complex forms charge partially or entirely by anisotropic materials such as metamaterials.We propose a system control rule to omit uncertainties,including the inevitable approximation errors resulting from the finite number of fuzzy signal power value basis functions in antenna networks.Moreover,both the stability and the tracking performance of the closed-loop robotic system are experimentally validated.The research lies within the scope of the improvement of speed,effectiveness,and precision of numerical methods applied to electro-magnetic modeling with complex structures,essentially rectangular metallic waveguides filled with isotropic or anisotropic metamaterials.Three axes of our research are presented:waveguides,filters,and antennas.The proposed controller does not require prior knowledge about the dynamics of the fuzzy system controller for antenna networks or the offline learning phase.In addition,this work contributes to solving the problem of non-visibility stations to ensure data transmission in wireless networks.The proposed solution maximizes inter-connection by using a fuzzy controlled antenna network,and the novelty guarantees nonlimited interconnection in wireless networks compared to traditional methods. | Chafaa Hamrouni | 2022 | Computers, Materials & Continua2022，，9： | 0 |
| 13 | Structural,dielectric and magnetic properties of Pr-,Tb-and Dy-doped(Bi_(0.95)RE_(0.05))(Fe_(0.95)Mn_(0.05))O_(3) ceramics synthesized by solid-state reaction method显示文摘The multiferroic(Bi_(0.95)RE_(0.05))(Fe_(0.95)Mn_(0.05))O_(3)(where RE=Pr,Tb and Dy)has been synthesized using solid-state reaction technique.Effects of Pr,Tb and Dy substitution on the structure,electrical and ferroelectric properties of(Bi_(0.95)RE_(0.05))(Fe_(0.95)Mn_(0.05))O_(3) samples have been studied by performing X-ray diffraction,dielectric measurements and magnetic measurements.The crystal structure of the ceramic samples have a monoclinic phase.The vibrating sample magnetometer(VSM)measurement shows a significant change in the magnetic properties of Pr-,Tb-and Dy-doped(Bi_(0.9)RE_(0.05))(Fe_(0.95)Mn_(0.05))O_(3).It is seen that coercive field(Hc)and remanent magnetization(Mr)increases for Pr but decreases for Dy and Tb. | Radheshyam Rai Shweta Thakur M.A.Valente Andrei L.Kholkin | 2013 | Journal of Advanced Dielectrics2013，3，4： | 0 |
| 14 | MAGNETIC AND FERROMAGNETIC RESONANCE STUDY OF Ni-Zn-Cu FERRITE SYSTEM显示文摘In recent years, the millimeter wave technique has been developed rapidly owing to the requirement of microwave remote sensor, high resolution radar, missile-guide and radio astronomy. And these requirments have prompted the study of gyromagnetic materials and devices used in millimeter wave. For gyromagnetic devices used in nonresonant region, the high saturation magnetization and narrow ferromag- | 李国栋 井宁 李德新 郭淑娇 王会宗 苏彦欣 张雅琴 | 1989 | Chinese Science Bulletin1989，34，13： | 0 |
| 15 | Effect of annealing on properties of Mg doped Zn-ferrite nanoparticles显示文摘A comparison of structural and magnetic properties of as-prepared and annealed(900 1C) Mg doped Zn ferrite nanoparticles(Zn1 xMgxFe2O4,with x=0, 0.1, 0.2, 0.3, 0.4 and 0.5) is presented. X-ray diffraction(XRD) studies confirmed the cubic spinel structure for both the as-prepared and annealed nanoparticles. The average crystallite size and lattice parameter were increased by annealing. Scanning electron microscopy(SEM)images also showed that the average particle size increased after annealing. Fourier transform infrared spectroscopy(FTIR) also confirmed the spinel structure for both series of nanoparticles. For both annealed and as-prepared nanoparticles, the O–Mtet.–O vibrational band shifts towards higher wave numbers with increased Mg concentration due to cationic rearrangement on the lattice sites. Magnetization studies revealed an anomalous decreasing magnetization for the annealed nanoparticles which is also ascribed to cationic rearrangement on the lattice sites after annealing. The measurement of coercivity showed a decreasing trend by annealing due to the increased nanoparticle size and better crystallinity. | K.Nadeem S.Rahman M.Mumtaz | 2015 | Progress in Natural Science:Materials International2015，25，2： | 0 |
| 16 | Enhanced structural and magnetic properties of microwave sintered Li–Ni–Co ferrites prepared by sol–gel method显示文摘The properties of lithium ferrites are very sensitive to chemical composition, synthesis method, and sintering techniques. Li–Ni–Co ferrites with compositional formula Li_(0.45-0.5x)Ni_(0.1)Co_xFe_(2.45-0.5x)O_4, where 0.00 ≤ x ≤ 0.1 in steps of 0.02 were prepared by chemical sol–gel method and sintered by microwave sintering technique. The x-ray diffraction patterns confirmed the formation of single phase with spinel structure in all the samples. The structural parameter viz.lattice constant, crystallite size, and x-ray density for these samples were studied and compared with those measured from samples of similar composition prepared by the sol–gel method and sintered by conventional sintering technique. Enhancement in the magnetic properties like Curie temperature, hysteresis parameters was observed by employing sol–gel synthesis combined with microwave sintering. The results obtained and mechanisms involved are discussed in the paper. | NANDeibam Nilima M Maisnam Sumitra Phanjoubam | 2019 | Chinese Physics B2019，28，2： | 0 |
| 17 | Master curve generation and modeling of ac conductivity for Mn_(0.7+x)Zn_(0.3)Si_(x)Fe_(2-2x)O_(4) spinel ferrite system显示文摘The compositional dependence of ac conductivity(δac),real(δ′)and imaginary(δ′′)parts of complex electric conductivity(δ*)was investigated as a function of temperature(T)and frequency(f) for Mn_(0.7+x)Zn_(0.3)Si_(x)Fe_(2-2x)O_(4),x=0.0,0.1,0.2 and 0.3 spinel ferrite system.The compositional dependence of lattice constant values suggested that the most of the substituted Si4+-ions reside at grain boundaries and only a few Si-ions are inside grains.The variation ofδ_(ac)(x,f,T)is explained on the basis of segregation and diffusion of Si4+ions at grain boundaries and grains,respectively,and the electrode effect.Thermal variation of ac conductivity at fixed frequency suggested two different mechanisms which could be responsible for conduction in the system.It is found that δ*is not the preferred presentation for dielectric data and the scaling process of real part of conductivity by normalized frequency and the scaled frequency were found unsuccessful.The fitting results of ac conductivity data with path percolation approximation were found suitable in low-frequency regime while in high-frequency regime,effective medium approximation(EMA)was found successful. | N.H.Vasoya Prafulla K.Jha K.G.Saija J.A.Bhalodia K.B.Modi | 2017 | Journal of Advanced Dielectrics2017，7，3： | 0 |
| 18 | Mssbauer spectra of MnFe_(2-2x)Al_(2x)O_4(0≤x≤0.4) ferrites显示文摘The effect of non-magnetic Al3+ ion doping on the magnetic properties of MnFe2-2xAl2xO4(0≤x≤0.4) spinel ferrites was studied using Mssbauer spectroscopy measurements at room temperature.From the Mssbauer study,it is observed that the resolved hyperfine sextets are due to the distribution of Fe ions on the two sublattices of the spinel ferrites.The value of the isomer shift obtained from the fitting of the Mssbauer spectra indicates that Fe ions are in +3 state.A paramagnetic doublet is observed at degree of inversion x=0.4,superimposed on the hyperfine sextets,indicating that the super-exchange interaction A-B decreases due to the dilution of sublattice by Al3+ ions.The hyperfine magnetic field decreases at both interstitial sites of tetrahedral(A) and octahedral(B) with the increase in Al concentration. | BATOO K M KUMAR S PRAKASH R ALIMUDDIN SONG J I CHUNG H JEONG H KOO B H LEE C G | 2010 | Journal of Central South University2010，17，6： | 0 |
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