NiCuZn Ferrites Research Articles

Enhancing electromagnetic properties of NiCuZn ferrites through Nb and Li Co-doping for wireless power transfer

With the rapid development of wireless charging technology, there is a growing demand for ferrite materials with high permeability, high saturation magnetic induction intensity, and low power loss. This study aims to enhance the electromagnetic performance of NiCuZn ferrite by co-doping Nb5+ and Li+. The influence of the doping levels Nb5+ and Li + on the morphology, crystal structure, and electromagnetic properties of NiCuZn ferrite were studied in detail. Structural analysis shows that the lattice constant decreases as the Nb5+-Li+ doping concentration increases, and the NiCuZn ferrite exhibits a high density and homogeneous microscopic morphology at the optimum concentration of x = 0.004. Specifically, at a doping concentration of x = 0.004, the magnetic permeability at 1 MHz measured at 1112.1, the saturation magnetic induction intensity reached 458.98 mT, and the power loss was minimized to 521.85 kW/m3, demonstrating significant improvement in the transmission power of wireless charging applications.

Micromorphology and electromagnetic properties of NiCuZn ferrites with Ba3Ti4Nb4O21 additives for Ka-band non-reciprocal microwave devices

Micromorphology and electromagnetic properties of NiCuZn ferrites with Ba3Ti4Nb4O21 additives for Ka-band non-reciprocal microwave devices

Ontology‐Based Data Acquisition, Refinement, and Utilization in the Development of a Multilayer Ferrite Inductor

A key aspect in the development of multilayer inductors is the magnetic permeability of the ferrite layers. Herein, the effects of different processing steps on the permeability of a NiCuZn ferrite are investigated. Dry‐pressed, tape‐cast, and cofired multilayer samples are analyzed. An automated data pipeline is applied to structure the acquired experimental data according to a domain ontology based on Platform MaterialDigital core ontology. Example queries to the ontology show how the determined process–property correlations are accessible to nonexperts and thus how suitable data for component design can be identified. It is demonstrated how the inductance of cofired multilayer inductors is reliably predicted by simulations if the appropriate input data corresponding to the manufacturing process is used.

Magnetic and dielectric properties of Mn2+ and Nb5+-doped NiCuZn ferrites for K-band junction circulators

Ni0.42-x/3Nbx/3Cu0.18Zn0.4MnxFe1.98−xO4−δ (x = 0–0.1) materials, possessing a high saturation magnetization, high dielectric constant, and narrow ferromagnetic resonance linewidth, were prepared via the solid-phase reaction method. The cation distribution, as well as the dielectric and gyromagnetic properties, were studied in detail. Mn2+ and Nb5+ incorporated in the lattice occupy tetrahedral site, causing the redistribution of cation and the reduction of A–B superexchange interaction. This leads to an increase in saturation magnetization followed by a decrease. The introduction of appropriate amounts of Mn2+ and Nb5+ ions reduces the magnetocrystalline anisotropy constant |K1| and thus reduces the ferromagnetic resonance linewidth (ΔH). Furthermore, high polarisability of Mn2+ and Nb5+ causes the increase in the dielectric constant of the ferrites. At x = 0.08, excellent gyromagnetic and dielectric properties, including a high dielectric constant (ε’ = 15.4@100 MHz), high saturation magnetization (4πMs = 4577 G), and narrow ferromagnetic resonance linewidth (ΔH = 129 Oe@9.55 GHz) for the NiCuZn ferrite, was achieved. Finally, a K-band microstrip circulator operating at 20.8 to 28 GHz was designed. The simulation showed that the isolation of the circulator in the working frequency band is greater than 20 dB, showing the potential of the prepared ferrites in microwave circulators.

Curie temperature and magnetic permeability regulation of Cr–Mg co-doped NiCuZn ferrite for tumor hyperthermia

The controllable Curie temperature and high magnetic permeability of NiCuZn ferrites make them promising candidates for magnetic thermal medium. However, the temperature control of existing NiCuZn ferrite materials is not accurate enough to achieve the low Curie temperature required for tumor hyperthermia. In order to further achieve the desired Curie temperature and facilitate the advancement of temperature control materials for tumor hyperthermia, Cr–Mg co-doped NiCuZn ferrite was studied. The study investigated the influence of varying concentrations of Cr3+ on the crystal structure and magnetic properties of Mg–NiCuZn ferrites. The results of structural characterization demonstrate that Cr–Mg co-doped NiCuZn ferrites exhibit high density and uniform distribution of elements. The introduction of Cr3+ leads to a reduction in lattice parameters and a preference for octahedral B-sites. The hysteresis loop results show that the saturation magnetization first increases and then decreases with the increase of Cr3+ concentration. Ni0.09Mg0.20Cu0.14Zn0.60Fe1.89Cr0.050O3.94 ferrite at 0.30 wt% of Bi2O3 exhibits optimal magnetic characteristics, including a saturation magnetization of ∼36.7 emu/g, low coercivity of ∼0.07 kA/m, high permeability of ∼982.43 @1 MHz, and an appropriate Curie temperature of 45.59 °C. Such permeability and Curie temperature can be used in the body cavity perfusion hyperthermia and deep thermal therapy.

Probing the influence of V2O5 and SBZKN composite additives on the magnetic characteristics and power loss of low-temperature sintered NiCuZn ferrites

Soft magnetic ferrites with exceptional magnetic characteristics and low power loss are in continuous demand in both academia and industry. In this work, a series of Ni0.22Cu0.31Zn0.47Fe1.98O4 ferrites doped with 0.5 wt% V2O5 and different SiO2-B2O3-ZnO-K2CO3-Na2CO3 (SBZKN) contents were synthesized using a conventional solid-phase method under a low sintering temperature of 925 ℃. The crystal phase, density, microstructure, grain size distribution, magnetic characteristics and power loss of the NiCuZn ferrites were studies to elucidate the composition-structure-property relationship. The underlying mechanisms were also thoroughly analyzed. The results showed that all the samples had a single-crystalline phase and dense microstructure when sintered at 925 ℃. As the SBZKN content increased, the density, saturation magnetization (Ms), residual magnetization (Br), complex permeability and quality factor (Q factor) exhibited a varying trend that increased initially and then decreased, while the coercivity (Hc) and power loss (Pcv) showed the opposite trend. The highest values of density, Ms, Br, magnetic permeability and Q factor of NiCuZn ferrites, obtained at an SBZKN content of 0.3 wt%, were 5.121 g/cm3, 51.07 emu/g, 188.47 mT, 389.8 and 114.3, respectively, while the lowest Hc and Pcv were obtained. The analysis showed that these outstanding magnetic and power loss characteristics were attributed to the uniform distribution of grain size and densification of NiCuZn facilitated by V2O5 and SBZKN incorporation.

Effect of Bi2O3-CuO Flux on the Microstructure, Soft Magnetic Properties, and Gyromagnetic Properties of NiCuZn Ferrites for LTCC Devices.

In this work, the electromagnetic properties of Ni0.22Cu0.31Zn0.47Fe2O4 (NiCuZn) ferrites doped with 0.3 wt% Bi2O3 + xCuO flux (x = 0.2, 0.4, 0.6, and 0.8 wt%) were studied. Doping resulted in a reduction in the sintering temperature to 900 °C. The doped ferrites were synthesized via the solid-state method. XRD patterns revealed that the prepared ferrites had a cubic spinel structure; thus, a moderate addition of flux did not change the crystal structure. The SEM images, as well as the density and grain size distribution of the samples, showed that the NiCuZn ferrites had densified, homogenized, and contained fully grown grains for x = 0.6 wt%. The sample exhibited good soft magnetic properties, with μ' reaching the maximum value of 245.4 for x = 0.6 wt% and ε', Ms, and Hc reaching the maximum values of 23.1, 28.06 emu/g, and 45.86 Oe for x = 0.8 wt%, respectively. Furthermore, the ferrites exhibited good gyromagnetic properties, with 4πMs reaching the maximum value of 1744 Gauss for x = 0.8 wt% and ΔH reaching the minimum value of 228 Oe for x = 0.6 wt%. NiCuZn ferrites were successfully sintered at a lower temperature (900 °C) by adding Bi2O3-CuO flux through LTCC technology and exhibited good soft magnetic properties and gyromagnetic properties. We envisage that these ferrites could be used in multilayer devices.

Cd2+-enhanced the structure, electrical and magnetic properties of low-temperature sintered NiCuZn ferrites

Ferrite materials are urgently demanded in high-frequency miniaturized power electronics for their high electromagnetic properties and high electrical resistivity. However, traditional NiZn ferrites are faced with low resistivity and high loss at low-temperature sintering, which severely restrict their applications. In this study, CdO was substituted into Ni0.22Cu0.2Zn0.58Fe2O4 ferrites at a presintered stage to refine the grain size and to achieve superior performance at low-temperature sintering. Interestingly, the electrical, magnetic and gyromagnetic properties of the NiCuZn ferrites exhibited a strong dependence on the concentration of Cd2+ ions. The Cd2+ ions entered into the lattice and substituted for Fe3+ at the octahedral site. SEM image results showed that CdO-substituted NiCuZn ferrites for the first sintering stage possess inhibition of abnormal grain growth, which can effectively solve the problem of shrinkage and grain compaction of ferrite materials in LTCC technology. Furthermore, to promote the grain growth at low sintering temperature, the optimized Bi2O3 additives were added at final sintering stage. The resistivity of the optimized Cd2+ ions is significantly enhanced from 2.41 × 108 Ω cm to 8.51 × 108 Ω cm. Finally, the NiCuZnCd (x = 0.15)-1.2 wt% Bi2O3 ferrites with the highest densification possess ρ = 8.51 × 108 Ω cm, ε′ = 18, tan δε = 6.0 × 10−3, μ′ = 81, fr = 117 MHz, tan δμ = 4.8 × 10−2 and ΔH = 281 Oe. This work provides a new doping method for the design of the high frequency LTCC device.

Li2O–B2O3–SiO2–CaO–Al2O3 glass-doped NiCuZn ferrite with high permeability and reliability for high-frequency MLCI application

Li2O–B2O3–SiO2–CaO–Al2O3 glass-doped NiCuZn ferrite with high permeability and reliability for high-frequency MLCI application

Gyromagnetic properties of Cu-substituted NiZn ferrites for millimeter-wave applications

In this work, NiCuZn ferrites with different CuO contents were prepared by solid-state method. The influences of the divalent Cu2+ on the crystal structure, microstructure and magnetic properties of NiCuZn ferrite were studied in detail. X-ray diffraction characterization showed that Cu2+ may either replace Ni2+ and enter into crystal lattice, or distributed at grain boundaries in the form of compound. SEM results showed that adding appropriate amount of CuO can promote grain growth and prepare dense NiCuZn ferrites. Especially, the density of the ferrite sample reaches its maximum value of 5.23 g/cm3 when the amount of CuO is 0.20. However, superfluous Cu2+ exists in the form of liquid phase at local grain boundaries once the content of Cu2+ reached 0.25. Moreover, the magnetic hysteresis loops revealed that the specific saturation magnetization first increased and then decreased and the highest value of 76.6 emu/g was obtained at x = 0.10. Consequently, a NiCuZn ferrite with an appropriate microstructure and with high density (5.16 g/cm3), high saturation magnetization (76.0 emu/g), low ferromagnetic resonance (FMR) linewidth (160 Oe) and 4πMs (4930 G) could be obtained at a Cu content of x = 0.15.

Microstructure, magnetic properties, and loss performance of the Cu-substituted MnZn ferrites

While the Cu substitution in NiCuZn ferrites is known to enhance densification and increase the initial permeability (μi), little is known about its effects in the MnZn based ferrites, which naturally possess a higher saturation magnetization (Ms) and μi. In this study, the effects of Cu substitution for Mn on the power MnZn ferrites (Mn0.71-xCuxZn0.22Fe2.07O4, x = 0.00–0.35) are investigated. With increasing Cu content, enhanced density, reduced porosity, and significant grain growth are observed. The cation distribution was determined using the Rietveld refinement, showing the strong tendency of Cu2+ ions to occupy the octahedral sites of the spinel lattice. The magnetization curves show reduced Ms with increasing Cu content. The magnetic anisotropy (|K|) was also determined from the magnetization curves using the law of approach to saturation and is seen to be increased by the increasing Cu content. The reduced Ms and increased |K| lead to the dramatic reduction of μi from 2503 (x = 0.00) to 151 (x = 0.35) at room temperature. Despite the reduced Ms at room temperature, the Curie temperature (TC) is seen to increase with increasing Cu content from x = 0.05 to x = 0.35, indicating the relocation of cations at an elevated temperature. The cut-off frequency (fr) is increased with increasing Cu content, which corresponds to the reduced μi. Moreover, the core loss (Pcv) of the MnCuZn ferrites was tested at 100kHz/200 mT, 200kHz/125 mT, and 300kHz/100 mT at room temperature, and is found to deteriorate with the increasing Cu content.

Evaluation of Structural, Magnetic, and Electromagnetic Properties of Co2+-Substituted NiCuZn Ferrites.

We report citrate gel-assisted autocombusted spinel-type Co2+-substituted NiCuZn ferrites and their electromagnetic properties. Several complementary techniques were used to investigate the influence of Co on structural and electromagnetic properties of Ni0.25-xCoxCu0.20Zn0.55Fe2O4 with x = 0.00-0.25 (step of 0.05). XRD analysis confirmed the highly crystalline single-phase cubic spinel structure with a prominent peak of the (311) plane. FE-SEM analysis showed the loss of porous gel structure (colloidal backbone) due to addition of cobalt into the present ferrite system. The EDAX analysis confirmed the presence of Ni, Cu, Zn, Co, and O in accordance with the relative stoichiometry of Co-substituted NiCuZn ferrite. The electrical resistivity of ferrites is observed to decrease when Co2+ ions are substituted, regardless of AC and DC. The dielectric properties (ε' and ε″) of ferrites exhibited a consistent decrease as the frequency increased, and this trend persisted even at higher frequencies. VSM analysis showed the normal magnetic hysteresis of the developed ferrite system. At x = 0.05, the saturation magnetization of the ferrite was obtained to be the highest among the other substitution levels of Co. The Curie temperature fell down when there was a higher concentration of cobalt in the ferrite system (x = 0.20). After reaching a specific temperature, the μi values decreased abruptly, with an increase in the temperature. The steady state may be deduced from the fact that the constant real component of the initial permeability, μ', remained unchanged. However, with decreasing frequency, the values of μ″ decreased dramatically. The present NiCuZn ferrite series displays the enhanced dielectric properties suggesting the capability of potential candidates for microwave absorption applications with enhanced electromagnetic properties.

Microstructure, magnetic, and power loss characteristics of low‐sintered NiCuZn ferrites with La2O3‐Bi2O3 additives

AbstractLow‐temperature‐sintered Ni0.5Cu0.125Zn0.375Fe1.98O4 ferrites co‐added with x wt% (x = 0.00‐0.25 wt%) La2O3 and 0.25 wt% Bi2O3 were successfully prepared via conventional solid‐phase reaction method. The phase composition, microstructure, magnetic properties, and especially power loss variation of the samples were systematically studied. The results showed that all samples possessed a single spinel phase structure at a sintering temperature of 900°C, exhibiting high degree of densification and uniform grains. The appropriate amount of La2O3 additive improved the saturation flux density and permeability of NiCuZn ferrites, simultaneously reducing the coercivity and power loss. The maximum permeability and the lowest power loss were achieved at x = 0.15 wt%. The corresponding sample had the homogeneous microstructure and excellent magnetic properties, being a promising low‐temperature co‐fired ferrite candidate for magnetic power components.

High cut-off frequency and low magnetic loss of Bi3+-Cr3+ co-substitution NiCuZn ferrite for chip inductors applications

With the rapid growth of high-frequency chip inductors, there is an urgent demand for NiCuZn ferrite that exhibits low magnetic loss and high cut-off frequency. To enhance its electromagnetic features, this study investigates the doping of Bi3+-Cr3 + ions into NiCuZn ferrite. The research examines the effects of different Cr3+ concentrations on the electric and magnetic properties, as well as the crystal structure of NiCuZn ferrites. The results showed that using a low sintering temperature of 925℃ can obtain NiCuZn ferrite with high population density and uniform microstructure. The inclusion of Cr3+ causes the lattice parameter to decrease, with a preference for octahedral B-sites. Furthermore, the saturation magnetization declines as the concentration of Cr3+ increases, according to the results of the magnetic hysteresis loops. The permittivity measurements demonstrate that the addition of Cr3+ ions can enhance permittivity and reduce dielectric loss. Lastly, NiCuZn ferrite co-doped with 0.30 wt% Bi2O3 and x = 0.15 of Cr3+ ions had appropriate saturation magnetization (∼57.05 emu/g) and coercivity (∼0.680 kA/m), meanwhile exhibited the highest dielectric constant (∼12.32 @ 1 MHz) and cut-off frequency (218 MHz), the lowest permeability loss tangent (0.0036@1 MHz) and imaginary part of the permittivity (0.54@1 MHz), making it a suitable for high-frequency chip inductors.

Sb2O3-doped Ni0.325Cu0.275Zn0.4Fe1.98O4 ferrite with enhanced permeability and larger cut-off frequency for high frequency low temperature co-fired electronic components

In order to solve the upper limit of device application frequency, it is urgent to develop new ferrites with high permeability and large cut-off frequency. Here, novel Sb2O3-doped NiCuZn ferrite ceramics (NCZF-x wt% Sb2O3, 0 ≤ x ≤ 0.35) were successfully fabricated via solid-state reaction method. This study found that Sb2O3, as an effective dopant, not only improved densification, but also contributed greatly to electro-magnetic properties. Especially, the permeability μ́ acquired the maximum value ∼ 210, and the cut-off frequency fr was 36 MHz at x = 0.05 wt%, while the dielectric loss tanδε was achieved 10–3 magnitude in the 10 ∼ 50 MHz. More importantly, the cut-off frequency fr with 134 MHz@x = 0.3 wt% and 129 MHz@x = 0.35 wt% were exceeded 120 MHz, which was significantly enhanced 4.47 ∼ 7.44 times than NiZnCo/NiCuZn ferrite. Outstanding electro-magnetic performance were achieved for NCZF-0.05/0.3 wt% Sb2O3: tanδε = 0.004@10 MHz, 0.008@50 MHz, μ́=210, fr = 36 MHz; tanδε = 0.02@10 MHz, 0.008@50 MHz, μ́=63, fr = 134 MHz, respectively. These excellent parameters in 0.05/0.3 wt% Sb2O3-doped NiCuZn ferrites were expected to be used as candidate materials in high-frequency electronic components.

Investigation on the micro-structure and magnetic properties of LMZBS-Bi2O3 doped low-temperature sintered NiCuZn ferrites

NiCuZn ferrites were widely used in communication and electronic information fields because of the high frequency, high impedance, wide band and low power loss. In this work, it reports that the (Ni0.2Cu0.2Zn0.6O)1.03(Fe2O3)0.97 ferrites were synthesized based on the solid-state reaction method and LMZBS (Li2CO3-MgO-ZnO-B2O3-SiO2)-Bi2O3 were also used as the dopant to regulate the micro-structure and magnetic properties. The crystal phase and micro-structure of the LMZBS-Bi2O3 doped NiCuZn ferrites were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The magnetic properties including saturation magnetization (Ms), coercive force (Hc), Q-factor and permeability as well as the power loss (Pcv) were investigated and analyzed in detail. The results showed that LMZBS (0.2wt%)-Bi2O3 (0.3wt%) doped NiCuZn ferrites exhibited a uniform and dense microstructure, and possessed the highest Ms, Q factor and magnetic permeability as well as the lowest Hc and Pcv. Overall, LMZBS-Bi2O3 doped NiCuZn ferrites possessed the outstanding micro-structure and magnetic properties, which make it promising for a series of applications.

Influence of Nb2O5 Additive on Elastic and Dielectric Properties of NiCuZn Ferrites

The influence of Nb2O5 additive on elastic and dielectric properties of NiZnCu ferrite is reported. The longitudinal and shear wave velocities were measured by ultrasonic pulse transmission method. The elastic constants increased as the Nb2O5 contents increased. The dielectric parameters such as dielectric constant (ɛ′) and dielectric loss tangents as a function of frequency and Nb2O5 additive composition for all samples at room temperature. The variations in the dielectric constant (ɛ′) and dielectric loss tangents values were explained using Maxwell–Wagner interfacial polarization according to Koops phenomenological theory. AC conductivity was increased with an increase in the frequency. A reduction in AC conductivity with Nb2O5 additive is reported.

Microstructure and electromagnetic properties of low-temperature sintered NiCuZn ferrite by co-doped Bi2O3 and Co2O3

Microstructure and electromagnetic properties of low-temperature sintered NiCuZn ferrite by co-doped Bi2O3 and Co2O3

Structural evolution and magnetic properties of NiCuZn ferrite synthesized via combustion reaction method

We report the fabrication of nickel-copper-zinc (NiCuZn) ferrites via a facile blowing-combustion method, where the grain size and morphology can be readily controlled by adjusting the sintering temperature. The effect of sintering temperatures on the structural evolution as well as the magnetic properties of the NiCuZn ferrites was systematically studied. It’s found that the Zn elemental content is highly dependent on the sintering temperature and would undergo evaporation when annealing at 800 °C, which consequently greatly affects the magnetic properties of NiCuZn ferrites.

BaTiO3-Refined NiCuZn Ferrites Towards Enhanced Pulse Detection Sensitivity for a High-Frequency Current Transformer

BaTiO3-Refined NiCuZn Ferrites Towards Enhanced Pulse Detection Sensitivity for a High-Frequency Current Transformer