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1.
Yin Liu Zhiguo Yi Jian‐jun Li Tai Qiu Fan‐fei Min Ming‐xu Zhang 《Journal of the American Ceramic Society》2013,96(1):151-156
Nanocrystalline Ni1?xZnxFe2O4 (0 ≤ x ≤ 1.0) powder with grain size of 30 nm was prepared using the spraying‐coprecipitation method. The obtained nanocrystalline Ni1?xZnxFe2O4 powder was sintered using conventional and microwave sintering techniques. The results show that the microstructure and magnetic properties of the sintered samples are obviously improved by microwave sintering of nanocrystalline Ni1?xZnxFe2O4 ferrite powder. The initial permeability of Ni1?xZnxFe2O4 ferrite increases with the increase in zinc concentration, although its resonance frequencies shift from high frequency to low frequency. The maximum initial permeability for microwave‐sintered Ni0.4Zn0.6Fe2O4 ceramic obtained at the temperature of 1170°C for 30 min reaches up to 360.9, and its resonance frequency is ~10 MHz. It may be attributed to the nanocrystalline Ni1?xZnxFe2O4 raw powder as well as the microwave sintering process, which results in a synergistic effect on improvement of the microstructure and magnetic properties. 相似文献
2.
《Ceramics International》2022,48(6):7533-7549
(1-x)SrFe10Al2O19/(x)Co0.6Zn0.4Fe2O4-(SFAO/CZFO) hard/soft nanocomposite ferrite materials were synthesized by ‘one-pot’ self-propagating combustion route. The co-existence of the two magnetic phases were confirmed by XRD, FESEM, EDS and VSM. The prepared nanocomposite samples were also characterized by TGA/DSC, Raman spectroscopy and VNA. Exchange coupling between the hard and the soft magnetic grains was observed by determining the switching field distribution (SFD) curve. As a result of the competing effects of exchange interaction and dipolar interaction, magnetic parameters were observed to be sensitive to the incorporation of soft magnetic phase into the nanocomposite. Results showed that with the inclusion of soft magnetic phase, exchange coupling behaviour between the hard and the soft ferrite phases had significant influence on the microwave absorption capacity of the samples. Related electromagnetic parameters and impedance matching ratio of the nanocomposite system were discussed. A minimum reflection loss of ?42.9 dB with an absorber thickness of 2.5 mm was attained by the nanocomposite (90 wt%)SrFe10Al2O19/(10 wt %)Co0.6Zn0.4Fe2O4 at a matching frequency of 11.45 GHz. This assured the candidacy of SrFe10Al2O19/Co0.6Zn0.4Fe2O4 nanocomposite as a promising microwave absorption material in the X-band (8–12 GHz). 相似文献
3.
Zongliang Zheng Huaiwu Zhang Qinghui Yang Lijun Jia 《Journal of the American Ceramic Society》2014,97(7):2016-2019
Significantly enhanced dielectric and loss characteristics have been observed in Ni0.4Zn0.6Fe2O4 ferrite with various Ba3Co2Fe24O41 (Co2Z) addition (x). Compared with pure NiZn and Co2Z ferrites, the composite ceramics obtain much refined grains and notable high‐frequency characteristics. With the introduction of Co2Z into NiZn ferrite matrix, the resistivity is largely increased from the order of 106 Ω cm to the order of 108 Ω cm and the frequency stability of permittivity is dramatically enhanced. Co2Z addition obviously improves the magnetic quality factor Q and reduces the dielectric loss of the ceramics at high frequency. For the samples with x = 20?30 wt%, permittivity ε′ is almost unchanged from 1 MHz to 1 GHz, Q is greater than 10 in a wide frequency range, and dielectric loss tan δε is observed to be of the order of 10?3 at 100 MHz, which is lower by two orders of magnitude compared with pure NiZn and Co2Z ferrites. These characteristics are all desirable for magneto‐dielectric ferrites in high‐frequency applications. 相似文献
4.
Pian Pian Ma Lei Yi Xiao Qiang Liu Lei Li Xiang Ming Chen 《Journal of the American Ceramic Society》2013,96(6):1795-1800
Effects of Mg substitution on order/disorder transition, microstructure, and microwave dielectric characteristics of Ba((Co0.6Zn0.4)1/3Nb2/3)O3 complex perovskite ceramics have been investigated. The ordered complex perovskite solid solutions are obtained in Ba((Co0.6?x/2Zn0.4?x/2Mgx)1/3Nb2/3)O3 ceramics (x = 0, 0.1, 0.2, and 0.3), and the ordering degree in the as‐sintered dense ceramics increases with increasing Mg‐substitution amount. The significantly improved Qf value is obtained in the present ceramics with increasing x, whereas the dielectric constant decreases slightly together with some increase of temperature coefficient of resonant frequency. The best combination of microwave dielectric characteristics is obtained in the composition of x = 0.3: εr = 33.7, Qf = 93 800 GHz, and τf = 9.6 ppm/°C. In the Mg‐substituted compositions, clear domain boundaries are obtained and the domain size increases as x increases, the highest Qf value is obtained when the domain size is about 40–60 nm in the ceramics with x = 0.3. The increased ordering degree and the fine ordering domain structure are considered to primarily contribute to the significant increase of Qf value in the Mg‐substituted Ba((Co0.6Zn0.4)1/3Nb2/3)O3 complex perovskite ceramics. 相似文献
5.
Vinuthna CH Kadiyala Chandra Babu Naidu Chandra Sekhar C Ravinder Dachepalli 《International Journal of Applied Ceramic Technology》2019,16(5):1944-1953
The cobalt-zinc ferrite (CZF) nanomaterials were prepared by citrate-gel method, and further calcined at 600°C. The single-phase cubic spinel structure of CZF was confirmed using the X-ray diffraction pattern. The average crystallite size was found to be in the range of 22-29 nm. The surface morphology was examined using the scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The average particle size of Co0.6Zn0.4Fe2O4 was determined to be 19 nm using TEM study which is supporting the average crystallite size measured from the X-ray diffraction studies. The Fourier-transform infrared spectra revealed the two strong absorption bands in the series of ferrites between 4500 and 500 cm−1 and these are responsible for the characteristic of spinel ferrites. The presence of elements Cu, Zn, and Co of CZF was confirmed by the elemental spectral signals of energy dispersive spectroscopy. At room temperature, the magnetic measurements of pure ZnFe2O4 and Co0.6Zn0.4Fe2O4 were evaluated based on hysteresis curves (M-H curves). The results expressed that the addition of nonmagnetic Zn2+ ions increases the magnetic behavior in the mixed CZF samples. The antimicrobial activity of the ZnFe2O4 and Co0.6Zn0.4Fe2O4 nanoferrites was tested against harmful microbes. 相似文献
6.
Pian P. Ma Lei Yi Xiao Q. Liu Lei Li Xiang M. Chen 《Journal of the American Ceramic Society》2013,96(11):3417-3424
Effects of postdensification annealing upon microstructures and microwave dielectric characteristics in Ba((Co0.6?x/2Zn0.4?x/2Mgx)1/3Nb2/3)O3 (x = 0, 0.1, 0.2, and 0.3) complex perovskite ceramics have been investigated. Long‐time annealing at temperatures below the order–disorder transition temperature enhances the cation ordering degree and promotes the ordering domain growth. The most significant improvement of Qf value is obtained together with the suppressed temperature coefficient of resonant frequency in the samples annealed at 1400°C for 12 h, while the dielectric constant decreases slightly. The Qf value of ceramics annealed at 1400°C mainly attributes to the enhanced cation ordering degree, because their low‐energy domain boundaries are not detrimental to the Qf value. As the annealing temperature increases close to the transition temperature, coarse ordering domains with high‐energy boundaries are formed, and then the Qf value steadily decreases because of the inferior domain structure, even the cation ordering degree increases. The microwave dielectric characteristics of Ba((Co0.6?x/2Zn0.4?x/2Mgx)1/3Nb2/3)O3 ceramics are affected by the common function of ordering degree and domain structure. The best combination of microwave dielectric characteristics is obtained in the composition of x = 0.3 after annealing at 1400°C for 12 h: εr = 33.2, Qf = 117 200 GHz, and τf = 8.6 ppm/°C. 相似文献
7.
Wei Wang Ri Chen Xiruo Zhao Yajun Zhang Jinliang Zhao Feng Li 《Journal of the American Ceramic Society》2013,96(7):2245-2251
Nanoparticles of Co0.6Zn0.4Fe2O4, with narrow size distribution, regular morphology, and high saturation magnetization, have been synthesized. The synthesis, involved a very rapid mixing of reducible metal cations with sodium borohydride, is carried out in a colloid mill and followed by a separate hydrothermal process. The microstructure and magnetic properties of the synthesized nanoparticles are characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). The effects of different synthesis conditions (synthesis temperature and reaction time) on the characteristics of the ferrite nanoparticles are discussed. The changes in cation contribution are revealed by the Raman study. The magnetic measurements explore that all the as‐synthesized samples are superparamagnetic in nature. The corresponding superparamagnetic behavior is explained by paramagnetic Langevin theory. Note that, the superparamagnetic Co0.6Zn0.4Fe2O4 ferrite nanoparticle, with excellent performance, can be synthesized at 160°C for a short reaction time (4 h). 相似文献
8.
《Ceramics International》2020,46(9):13095-13101
In this work, Li2Mg0.6−xCoxZn0.4SiO4 ceramics (x = 0–0.4) added with 3 wt% Li2O–B2O3–Bi2O3–SiO2 (LBBS) glass were synthesised using the solid-state reaction method. The effects of substituting Co2+ for Mg2+in Li2Mg0.6−xCoxZn0.4SiO4 ceramics on crystal structure, microstructure, densification, crystallisation and microwave dielectric properties were investigated. X-ray diffraction patterns showed that monoclinic Li2MgSiO4, monoclinic Li2ZnSiO4 and orthorhombic Li2CoSiO4 formed finite solid solution in Li2Mg0.6−xCoxZn0.4SiO4 ceramics. Clear grain boundaries were observed via scanning electron microscopy. The substitution of Co2+ for Mg2+ increased grain size, densification, crystallinity degree and dielectric constant; it also reduced the dielectric loss of the ceramics to a certain extent. The absolute values of τf were positively related to the crystallinity degree. Li2Mg0.55Co0.05Zn0.4SiO4 ceramic added with 3 wt% LBBS and sintered at 900 °C exhibited considerable microwave dielectric properties of εr = 5.8, Q × f = 47,518 GHz and τf = −74.8 ppm/°C. Therefore, the ceramic is considered a candidate low-temperature co-fired ceramic material for substrate and filter applications. 相似文献
9.
Copper‐substituted spinel Zn‐Mg ferrite nanoparticles as potential heating agents for hyperthermia
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Mohammad Ansari Ashkan Bigham Sayed Ali Hassanzadeh Tabrizi Hossein Abbastabar Ahangar 《Journal of the American Ceramic Society》2018,101(8):3649-3661
CuxZn0.5‐xMg0.5Fe2O4 (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) ferrite nanoparticles are synthesized via thermal treatment technique using polyvinyl alcohol (PVA) as a capping agent. The effect of Cu2+ ions substitution on the magnetic and structural properties of ZnMg ferrite nanoparticles is assessed. X‐ray diffraction (XRD) results prove the formation of spinel cubic ferrite with nanocrystalline structure. It is observed by increasing Cu2+ ions content in Cu2+‐substituted ZnMg ferrite samples, the lattice constant decreases. The field‐emission scanning electron microscopy (FESEM) micrographs indicate that all samples have sizes in nanometer scale with almost spherical morphology and ZnMg ferrite nanoparticles size is increased as the result of Cu2+ substitution. Magnetic data show that by increasing in Cu2+ content, the saturation magnetization (Ms) increases up to x = 0.3 and then declines with the addition of more Cu2+ ions in the samples. To assess the heat release of Cu2+‐substituted ZnMg ferrite nanoparticles, an alternating magnetic (AC) field is applied. The results show an upward trend for the samples in the temperature vs time chart, as a result of increasing in Ms of the samples. The Cu0.3Zn0.2Mg0.5Fe2O4 sample exhibits a temperature increase up to 43°C during 510 seconds in the exposure of 125 Oe magnetic field intensity. The cell compatibility of the samples is investigated using osteoblast‐like cells (MG63). Results show that the substitution of Cu2+ significantly affects the cell compatibility of the ZnMg ferrite nanoparticles. 相似文献
10.
《Ceramics International》2020,46(9):13102-13106
The Ba1-xCaxFe11.4Co0.6O19 (x = 0.0, 0.2, 0.4, 0.6, and 0.8) composites with wide-bandwidth and good absorption performance were prepared. The MS of ceramics increases from about 62.4 to 83.4 emu g−1 as x rises from 0 to 0.6, which demonstrates that the desirable magnetic properties of such ceramics is obtained by adjusting the content of Ca2+. A bandwidth of reflection loss (RL) below - 5 dB can be obtained for frequencies from 5.9 to 18 GHz with the Ba0.4Ca0.6Fe11.4Co0.6O19 ceramic and a thickness of 2.0 mm, and a larger RL value of −34.1 dB is observed at 8.2 GHz for the Ba0.6Ca0.4Fe11.4Co0.6O19 ceramic. These results suggest the developed ceramics could act as effective and wide-bandwidth microwave absorbing materials to meet commercial and military applications. 相似文献
11.
《Ceramics International》2023,49(8):12469-12480
We report the synthesis of Ca-doped Mg–Zn ferrite Mg0.4Zn(0.6-x)CaxFe2O4 nanomaterials with x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 through citrate precursor approach and their structural, morphological, optical, photocatalytic, and antimicrobial properties were systematically studied. The prepared nanoferrites's cubic spinel structure with an average crystallite size of 15–38 nm was evaluated by the XRD examination. The spherical morphology of these ferrite nanoparticles was seen from scanning electron microscopy (SEM). The observed bands at 560 cm−1 and 406 cm−1 in the FTIR spectra confirmed the spinel structure of the synthesized nanoferrite. The optical study confirmed an optical band gap of 1.60 eV–1.86 eV. The photocatalysis was done for the degradation of rhodamine B dye solution under UV light. All the synthesized nano ferrites displayed a promising antimicrobial potential upon Candida albicans fungi. Mg0.4Zn0.1Ca0.5Fe2O4 nanoparticles have a better photocatalytic response (99.5%) for the degradation of rhodamine B dye and show superior antimicrobial activity (96.1%) for the inhibition of Candida albicans fungi. 相似文献
12.
Sonal Singhal Rimi Sharma Tsering Namgyal Sheenu Jauhar Santosh Bhukal Japinder Kaur 《Ceramics International》2012,38(4):2773-2778
Nanoparticles of Co0.5Zn0.5AlxFe2?xO4 (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized by sol–gel method and the influence of Al3+ doping on the properties of Co0.5Zn0.5Fe2O4 was studied. X-ray diffraction studies revealed the formation of single phase spinel type cubical structure having space group Fd-3m. A decreasing trend of the lattice parameter was observed with increasing Al3+ concentration due to the smaller ionic radii of Al3+ ion as compared to Fe3+ ion. TEM was used to characterize the microstructure of the samples and particle size determination, which exhibited the formation of spherical nanoparticles. The particle size was found to be increases up to ~45 nm after annealing the sample at 1000 °C. Electrical resistivity was found to increase with Al3+ doping, attributed to the decrease in the number of Fe2+–Fe3+ hopping. The activation energy decreased with increasing Al3+ ion concentration, indicating the blocking of conduction mechanism between Fe3+–Fe2+ ions. The value of saturation magnetization decreased, when Fe3+ ions were doped with Al3+ ions in Co0.5Zn0.5Fe2O4; however, the coercivity values increased with increasing Al3+ ion content. 相似文献
13.
Optical and Microwave Dielectric Properties of Zn‐Doped MgAl2O4 Transparent Ceramics Fabricated by Spark Plasma Sintering
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Ping Fu Yong Xu Wenzhong Lu Wen Lei Xuehua Wang Xuefeng Ruan 《International Journal of Applied Ceramic Technology》2015,12(1):116-123
(Mg1?xZnx)Al2O4 transparent ceramics were fabricated by spark plasma sintering technique at 1325°C for 10 min. A small mount of Zn2+ addition to MgAl2O4 ceramics was very effective to the performance improvement, while further increase in Zn‐doped content would give rise to the optical transmittance deterioration. The optical and microwave dielectric properties of MgAl2O4 transparent ceramics were improved by Zn substitution for Mg. The in‐line transmittance of the (Mg1?xZnx)Al2O4 (x = 0.02) ceramics can be as high as 70% at λ = 550 nm and 86.5% at λ = 2000 nm, respectively. The dielectric constant εr of (Mg1?xZnx)Al2O4 just varied from 8.32 to 8.54, however, the Q × f value increased significantly up to a maximal value of 66,000 GHz at x = 0.02. Moreover, the τf of (Mg1?xZnx)Al2O4 transparent ceramics changed from ?74 to ?65.5 ppm/°C. With the increasing of Zn‐doped content, the average grain size and the porosity increased, which was the primary reason for the change in optical and microwave dielectric properties. 相似文献
14.
《Ceramics International》2020,46(10):15925-15934
Herein, reduced graphene oxide/cobalt-zinc ferrite (RGO/Co0.5Zn0.5Fe2O4) hybrid nanocomposites were fabricated by a facile hydrothermal strategy. Results revealed that the contents of RGO could affect the micromorphology, electromagnetic parameters and electromagnetic wave absorption properties. As the contents of RGO increased in the as-synthesized hybrid nanocomposites, the dispersibility of the particles was improved. Meanwhile, numerously ferromagnetic Co0.5Zn0.5Fe2O4 particles were evenly anchored on the wrinkled surfaces of flaky RGO. Besides, the obtained hybrid nanocomposites exhibited superior electromagnetic absorption in both X and Ku bands, which was achieved by adjusting the RGO contents and matching thicknesses. Significantly, when the content of RGO was 7.4 wt%, the binary nanocomposites showed the optimal reflection loss of -73.9 dB at a thickness of 2.2 mm and broadest effective absorption bandwidth of 6.0 GHz (12.0–18.0 GHz) at a thin thickness of merely 2.0 mm. The enhanced electromagnetic absorption performance was primarily attributed to the multiple polarization effects, improved conduction loss caused by electron migration, and magnetic loss derived from ferromagnetic Co0.5Zn0.5Fe2O4 nanoparticles. Our results could provide inspiration for manufacturing graphene-based hybrid nanocomposites as high-efficient electromagnetic wave absorbers. 相似文献
15.
Qisheng Yin Yingli Liu Xin Wang Kui Liu Jian Wu Jie Li Jianfeng Chen Shifan Lu 《Journal of the American Ceramic Society》2023,106(11):6837-6848
Herein, the crystal structure, dielectric properties, and gyromagnetic characteristics of Zn–Sn codoped Y3ZnxSnxFe5−2xO12 (x = 0.0–0.5) prepared using a conventional ceramic process were investigated. According to the first-principles’ calculations and complex crystal bonding theory, Zn2+–Sn4+ codoping can increase the relative dielectric constant (εr) by enhancing the average ionicity. The x-ray photoelectron spectroscopy (XPS) and Raman analysis results indicate that an appropriate amount of Zn2+–Sn4+ codoping can help improve the microscopic morphology, maintain the appropriate ratio of divalent iron ions, and reduce the microwave magnetic and electrical losses of YIG ferrites. The optimized microwave properties are as follows. Y3Zn0.3Sn0.3Fe4.4O12 after sintering at 1400°C; εr = 15.6; dielectric loss, that is, tanδε = 4.3 × 10−4; saturation magnetization, that is, 4πMS = 2244 G; ferromagnetic resonance linewidth, that is, ΔH = 37 Oe. These properties can help improve the performance of high-frequency microwave components by enhancing the properties of ferrite. 相似文献
16.
《Ceramics International》2022,48(3):3417-3425
Zn-doped nickel ferrite nanoparticles (ZnxNi(1-x)Fe2O4) were synthesized using the co-precipitation technique. The structural and compositional studies of the ZnxNi(1-x)Fe2O4 nanoparticles revealed their face-centred cubic spinel structure and an appropriate amount of Zn doping in nickel ferrite nanoparticles, respectively. The morphological analysis had been carried out to obtain the particle size of the synthesized nanoparticles. The magnetic studies revealed the superparamagnetic nature of the ZnxNi(1-x)Fe2O4 nanoparticles, and the maximum magnetization of 30 emu/g for the Zn0.2N0.8Fe2O4 sample. The M ? H curves were fitted with the Langevin function to obtain the magnetic particle diameter of ZnxNi(1-x)Fe2O4 nanoparticles. The electrical conduction in ZnxNi(1-x)Fe2O4 nanoparticles was explained through the Verway hopping mechanism. The Zn0.2N0.8Fe2O4 nanoparticle exhibited a higher electrical conductivity of 42 μS/cm and surface charge of ?29/7 mV due to the enhanced hopping of Fe3+ ions in the octahedral sites. Owing to this nature, they were identified as the suitable candidates in the applications such as thermoelectrics, hyperthermia, magnetic coating and for the preparation of conducting ferrofluids. 相似文献
17.
《Ceramics International》2017,43(7):5427-5433
(Mg0.95Zn0.05)2(Ti0.8Sn0.2)O4 powder was synthesized by a solid state reaction. Then, Ni0.4Zn0.6Fe2O4 was grown on the (Mg0.95Zn0.05)(Ti0.8Sn0.2)O4 particles in a hydrothermal environment to form a core-shell structure. (1-x)(Mg0.95Zn0.05)2(Ti0.8Sn0.2)O4@xNi0.4Zn0.6Fe2O4 composite ceramics were sintered at 1200 °C with these powders. XRD, SEM, TEM analyses indicated that high dense core-shell ceramics without any foreign phase were obtained. Different types of sharp interfaces were self-assembled owing to the minimization of direct elastic energy in the hydrothermal environment. The composites enjoy good magnetic and dielectric properties, especially, good microwave dielectric properties with high saturation magnetization when the ferrite content is 0.3–0.5. The results provided a powerful experimental basis for the sensor and transducer. 相似文献
18.
Formation of BaFe12−xNbxO19 and its high electromagnetic wave absorption properties in millimeter wave frequency range
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Chuyang Liu Yujie Chen Yangyu Yue Yu Tang Zongrong Wang Ning Ma Piyi Du 《Journal of the American Ceramic Society》2017,100(9):3999-4010
BaFe12?xNbxO19 (BFNO, x=0‐0.6) powders with Nb5+ substituting for Fe3+ were prepared by sol‐gel method. The formation process and electromagnetic (EM) wave absorption properties of the BFNO are investigated in detail. With Nb5+ content increasing from x=0 to x=0.6, the formation temperature of barium ferrite phase without heat time increases from ~700°C to ~900°C, while the appearance temperature of typical plate grains decreases from ~1300°C to ~1100°C, and the crystallization ability decreases at 600°C‐900°C, while the grain size increases gradually at 1100°C‐1300°C. Increasing sintering temperature and time promote the formation of barium ferrite phase and grain growth in all the samples. The ε′ and ε″ of the sample with x=0.6 sintered at 1300°C for 3 hours reach highest of ~7.9 and ~0.95 over 26.5‐40 GHz. Multiresonance peaks in permeability decrease from 40+ GHz to ~30 GHz with x rising from 0 to 0.6. Ultimately, small RLmin of ~?42 dB, thin dm of ~0.76 mm, and broad bandwidth of >12 GHz can be exhibited simultaneously around millimeter wave atmospheric window of 35 GHz. 相似文献
19.
Hsing‐I Hsiang Li‐Then Mei Chi‐Shiung Hsi Wei‐Cheng Wu Jer‐Hao Wu Fu‐Su Yen 《International Journal of Applied Ceramic Technology》2013,10(1):160-167
The Bi2O3–B2O3–ZnO–SiO2 (BB35SZ) glass effects on the sintering behavior and magnetic properties of Bi–Zn co‐doped Co2Y ferrites were investigated in developing low‐temperature‐fired ferrites. The results indicate that BB35SZ glass can be used as a sintering aid to reduce the densification temperature of Co2Y ferrites from 1300°C to 900°C. The 2(Ba0.9Bi0.1O)·2(Zn0.4Co0.4Cu0.2O)·6(Fe1.97Zn0.03O3) ferrite with 4 wt% BB35SZ glass can be densified below 900°C, exhibiting an initial permeability of 3.4 and quality factor of 55. This process provides a promising candidate for multilayer chip magnetic devices for microwave applications. 相似文献
20.
Ngo Tran Ruey-Bin Yang Woo Hyun Jeong Do Hung Manh The-Long Phan Bo Wha Lee 《Journal of the American Ceramic Society》2022,105(6):4122-4134
Controlling material structure and its electromagnetic properties, including complex permittivity and permeability, could enhance the microwave absorption performance of the material in terms of reflection loss and effective absorption bandwidth. In this study, La-substituted barium hexaferrite, Ba3−xLaxCo2Fe24O41 (x = 0, 0.1, 0.3, and 0.5) compounds were successfully prepared using the solid-state reaction method, and their corresponding microstructures, static magnetic properties, and electromagnetic features in 2–18 GHz were investigated. The doping of La content increased saturation magnetization, coercivity, and remnant magnetization. The Ba2.7La0.3Co2Fe24O41 epoxied sample with 3.5 mm thickness possessed an excellent microwave absorption of −47.3 dB at 3.52 GHz, and its corresponding effective absorption bandwidths were 3.75 GHz (2.25–6 GHz) and 0.57 GHz (17.43–18 GHz). It is shown that doping with various La concentrations on Ba3Co2Fe24O41 can be used as an effective technique to tune the performance of microwave absorbers based on barium hexaferrite. 相似文献