Multilayer Chip Inductors Research Articles

Microwave absorption properties of ytterbium substituted X-type ferrite in P-, L-, S-, and C-band

Ba1.5Sr0.5Zn2Fe28-xYbxO46 (x = 0.00, 0.07, 0.14, 0.21, and 0.28) hexaferrite were synthesized via sol-gel auto-combustion route to investigate the microwave absorption performance in different frequency bands. The structure has a single phase, and the variation in lattice parameter was observed due to Yb-content as host iron Fe3+ and substituted Yb3+ having different ionic radii. Microwave absorbing materials (MAMs) need to be lightweight, and the maximum crystallite size of prepared material is 41 nm. The physical properties vary with substitution, and the X-ray density value is higher than the bulk density, and the porosity of the prepared sample increases when the bulk density decreases. Micro-strain values are inverse to the crystallite size because Yb3+ has larger ionic radii than Fe3+. Rietveld refinement of the XRD patterns was conducted with a lower significance value. FTIR bands observed between 414 and 500 cm−1 are present due to iron-oxygen bond stretching and bending vibrations at octahedral and tetrahedral lattice sites. The cation distribution is highly responsible for the peak position of octahedral and tetrahedral sites—the dielectric constant increases with frequency because of dipole, interfacial, and electronic/atomic polarization. AC conductivity is very low, reflecting that the material can be used as a dielectric medium in the microwave frequency range's L, S, and C bands. The best MAM among all prepared materials is Ba1.5Sr0.5Zn2Fe27.72Yb0.28O46 which can be used for global positioning systems, weather radar, and satellite feeds as it has an excellent dielectric loss, remarkable tangential loss, and the reflection loss in P-, L-, S-, and C-bands. Other real-life application of all prepared materials are multi-layer chip inductor and longitudinal media recording.

Microwave absorption properties of β-type ferrites: Influence of Nd-loading percentage on structural, spectral, elemental, and electrical features

Hexagonal ferrites have drawn significant attention due to a broad range of telecommunication and stealth technology applications. β-Type hexagonal ferrites are rarely used in various technological applications. In the current work, Nd3+ substituted polycrystalline β-type hexagonal ferries with composition LiFe11-x NdxO17 (x = 0.0–0.04, ∇ x = 0.01) were prepared using the sol-gel method. All prepared samples were sintered at 1000 °C for 4 h. The influence of Neodymium (Nd3+) on its structural, electrical, and dielectric properties was investigated. Lattice parameters (a, c) and Vcell increased with varying Neodymium substitution levels. The crystallite size was measured in the range of 38–42 nm. Fourier Transform IR (Infrared) spectroscopy exposed the presence of two spectral bands at 416 to 449 cm−1 and 449 to 489 cm−1. XPS (x-ray photoelectron spectroscopy) analysis verified the presence of metal ions and their chemical states in all prepared samples. The dielectric constant, loss, tan δ, and σac (ac-conductivity) decreased by increasing Nd3+ content. Jonscher's power law explains the conduction mechanism of charge carriers in all fabricated samples. The influence of relaxation time and grain boundaries on the electrical characteristics of prepared nanomaterials was investigated by impedance analysis. SEM (scanning electron microscopy) confirms the successful formation of β-hexaferrite nanomaterials. A minimum reflection loss of −32.08 dB was observed at 1.5 GHz for the x = 0.04 sample. This minimum reflection loss evidenced the novelty of the research and suggested their usefulness in high-frequency microwave applications. All samples investigated in this research work are suitable for high-frequency applications, multilayer chip inductors, and EM interference shielding.

Unraveling the dielectric and electrical properties of binary BaTiO3/Ba0.98Ca0.01Mg0.01Fe12O19 composites

In this study, composite materials of barium titanate (BaTiO3 or BTO) phase embedded with different contents of Ba0.96Ca0.02Mg0.02Fe12O19 (BCMFO) hexaferrite phase as (BTO)1-x/(BCMFO)x (x = 0.00, 0.02, 0.05, 0.10, and 1.00) composites were prepared. The successful formation of the desired samples was established via X-ray diffraction. Additional peaks showing a chemical reaction between the two phases as a result of the heat treatment were not found. The co-existence of the two-component phases was further confirmed via field emission scanning electron microscopy and energy dispersive X-ray spectroscopy, wherein rounded spherical grains (with nanometric size <200 nm) correspond to the BTO phase while plates-like shaped grains with larger size (with micrometric size) correspond to the BCMFO hexaferrite phase. This study also investigates the impact of the composition ratio of BCMFO to BTO composites on electrical and dielectric properties through comprehensive parameter-based analyses using impedance spectroscopy. Parameters explored include conductivity, dielectric constant, dielectric loss, dissipation factor, and complex modulus, alongside Nyquist analysis of Cole-Cole modulus functions. The activation energies range from approximately 40 to 431 meV. The study suggests the involvement of electron-hole hopping, polaronic, and ionic mechanisms in conduction within intra-grains and grain boundaries. Results reveal strong dependencies of all dielectric parameters on both frequency and composition ratio. Nyquist plots demonstrate distinct semicircles reflecting contributions from intra-grain, grain boundary, and BCMFO components. The extent of dielectric loss is found to be influenced by factors such as porosity, density, homogeneity, and grain size, influenced by sintering and composition conditions. The presence of these semicircles in Nyquist plots indicates different relaxation phenomena associated with charge carrier mobility within the grain boundary and the grain itself. Additionally, the diameter of these semicircles correlates with the resistance values of both grain boundary and grain. These findings suggest the potential for tuning dielectric parameters by adjusting composition ratios, particularly relevant for applications in micro-device technologies such as multilayer chip capacitors and multilayer chip inductors, facing new challenges.

Structural and magnetic characterizations of Co substituted Ni-Cu-Zn nanoferrites

Co substituted Ni-Cu-Zn nanoferrites with the compositional formula Cox Ni0.5−x Cu0.3 Zn0.2 Fe2O4 (where x=0.0, 0.1, 0.2) were synthesized by Citrate Precursor method. The as prepared samples were calcined at 950o C for 30 min using a conventional muffle furnace. Characterizations were carried out using XRD, FESEM and VSM techniques.XRD peaks conform to spinel type structure. FESEM micrographs showed surface morphology. Magnetic characterizations were carried out by employing VSM technique. This paper investigates the synthesized samples as potential electronic materials for Multilayer Chip Inductor (MLCI).

Magnetodielectric, elastic, Rietveld refinement and absorption properties of Nd–Cu co-doped Co–Zn nano ferrites: Development of meta-absorbers for wide frequency regime

Currently, Electromagnetic (EM) pollution is harmful to human health because of the generation and propagation of high-frequency EM waves from electronic devices. The absorbing materials with outstanding properties are highly desirable. Meta-absorbers with extraordinary electromagnetic wave absorption, outstanding EM shielding ability, and featured dissipation efficiency are still worth challenging in the surrounding environments. The meta-absorbers were fabricated, designed, and simulated to address the challenges. Nd–Co co-doped Co–Zn spinel nano ferrites (Co0.5Zn0.5-xCuxFe2-yNdyO4 with x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, y = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were prepared. XRD, FESEM, FTIR, and VSM were used to study the structure, phase, vibrational, elastic, and magnetic features of the Nd–Co co-doped Co–Zn ferrites, respectively. Rietveld refinement of the Nd–Co co-doped Co–Zn ferrites was evaluated by FullProf software. Wyckoff locations and occupancy of the already present cations and anions were refined. The bond lengths and unshared-shared edges were determined using the Bertaut method. The detailed phase occurrence, force constant, and elastic features of Nd–Co co-doped Co–Zn ferrites were also investigated. The mixed shapes of grains like elliptical, circular, and hexagons were noticed from FESEM images. The magnetization and coercivity were reduced with the Nd–Cu doping. Switching field and high-frequency response were also presented for the Nd–Cu co-doped Co–Zn ferrite. The dielectric properties like complex permittivity and permeability depicted higher response at high frequency due to interfacial polarization in prepared ferrites. The reflection loss (RL) of −74.1 dB was noticed at 1.99 GHz for x = 0.4, y = 0.08. However, the reflection loss of −63.9 dB at 2.24 GHz was observed for x = 0.5, y = 0.1. Meta-absorbers of Nd–Cu co-doped NiZn were designed and simulated. The wideband absorptivity is depicted for Nd–Cu co-doped CoZn ferrite as substrate material at x = 0.0 y = 0.00, x = 0.1 y = 0.02, and the absorptivity remains highest for θ = 0 deg. The absorptivity significantly reduces with the increase of incidence angle. Meta-absorbers based on Nd–Cu co-doped Co–Zn ferrites are good future candidates for EMI (electromagnetic interference), MLCIs (multilayer chip inductors), electromagnetic shielding, and 5G-mobile antenna purposes in high-frequency applications.

Structural, morphological, dielectric, and spectral properties of Sr-Mg-Ho X-type magnetic nano materials suitable for microwave absorption application

Holmium (Ho3+) substituted Sr2Mg2Fe28O46 X-type hexa-ferrites were synthesized using the sol-gel auto-combustion route. The single phase of Sr2Mg2Fe28-xHoxO46 where 0.00 ≤ x ≤ 0.20, Δx = 0.05, X-type hexa-ferrites was confirmed using XRD peaks. The crystalline size was studied from XRD data and found to be in the 11 nm–24 nm range. The micro strain increased with the substitution of Ho3+. FTIR exposed the specific stretching vibration and absorption peaks in the 400 cm−1 - 600 cm−1 range. The force constant (ko) decreased from 1.74 N/cm to 1.65 N/cm with the increasing concentration of Ho3+. The grain size range is 371–493 nm, measured by SEM analysis, and plate-like structure plays a crucial role in enhancing the permeability of magnetic material. Transmission electron microscopy (TEM) analysis showed the hexagonal structure of X-type ferrites (x = 0.20). The results of the X-ray photoelectron spectroscopy (XPS) experiment confirmed the presence of all metal ions in the given composition with their required valences. The dielectric constant, dielectric loss, and tangent loss are found to increase with the substitution of the Ho3+ ion. In addition, the higher values of dielectric parameters and dielectric loss suggest that the material may suitable for high-frequency applications and best for microwave absorbers. Our aim is to discuss the characteristics and applications of microwave absorption materials, understand their behavior, and contribute to the development of upcoming novel devices. The resonance peak's appearance shows that these materials are best for multilayer chip inductors and EMI attenuation.

Impact of samarium on structural and dielectric properties of U-type hexaferrites synthesized by a sol-gel auto combustion route: Analysis of XPS, Raman and FTIR spectra

In this work, the impact of rare earth element samarium "Sm" substitution on Ba4Co2SmxFe36-xO60 U-type hexaferrites was studied in detail. Five compositions with step size x = 0.00, 0.025, 0.050, 0.075 and 0.1 were synthesized. These five series were prepared using the sol-gel auto-combustion method and the samples were sintered for 6 h at 1250 °C. The synthesized samples were characterized by XRD, FTIR, Raman Spectroscopy, X-ray photoelectron Spectroscopy and vector network analyzer (VNA). The structure crystallography of Ba4Co2SmxFe36-xO60 was examined via XRD. The impact of Sm3+ substitution was assessed across all lattice parameters. Lattice constants 'a' and 'c' were found between 5.886 and 5.881 Å and 113.179 to 113.037 Å, respectively. FTIR was used to learn more about the crystal structure and atomic vibrations between 400 and 1000 cm−1 wave number, where higher frequency bands appear at 570 cm−1 (tetrahedral site) and the lower frequency band occurred at 424 cm−1 due to the metal-oxygen stretching vibration (Fe-O) bond at the octahedral site. Each spectrum supported a U-type hexagonal structure i.e. an investigation of the chemical and intermolecular bonds via Raman spectra. XPS confirms the presence of elements in materials. Different dielectric parameters were observed in the 1 MHz to 6 GHz range of all prepared samples. Cole-Cole graphs of prepared materials highlighted the influence of grain boundaries. A solitary semicircle in the impedance of a specific section of grain boundaries was evidenced through Cole-Cole plots. Dielectric properties strongly depend on electron hopping between Fe2+ and Fe3+ ions. The optimized parameters suggest the utility of these materials in microwave devices, multilayer chip inductors and high-frequency electrical circuit applications to reduce skin effects.

Dielectric, reflection loss and physicochemical studies of Cr doped Ba–Sr based W type hexagonal ferrites for microwave absorption applications

The utilization of hexagonal structures in nano ferrites has been employed for absorption because of their dielectric, attenuation characteristics, and reflection losses. Electromagnetic pollution is one of the significant issues in cleaning the environment. Electronic devices produce pollution and are hazardous to human health. Therefore, ferrite materials have been used for absorption purposes. In this study, the impact of chromium substitution on the structural and dielectric specifications of the Barium-strontium-based W-type hexagonal ferrites has been investigated and used for microwave absorption application. The sol-gel auto-ignition process prepared w-type hexagonal ferrites with Ba0.5Sr0.5Mg2CrxFe16-xO27 (x = 0.0, 0.1, 0.2, 0.3, and 0.4). According to XRD examination, the formation of single-phase W-type hexagonal ferrites was proven. The synthesized composition is confirmed to be nanocrystalline because the calculated crystallite size value is in the nanometer range. FTIR analysis confirmed the structure of W-type hexagonal ferrite. Raman spectroscopic study examined the vibrational and rotational modes of molecules. Survey spectra of XPS, which include Ba, Sr, Mg, Fe, Cr, and O, confirmed the presence of all constituent elements. SEM analysis confirmed that the sample contains grains with a hexagonal platelet shape. The results showed that increasing chromium concentration reduced the dielectric permittivity, tan loss, and ac conductivity. At x = 0.4, the reflection loss value is very low. The recorded value is −79.62 dB, corresponding to a frequency of 5.92 GHz, with a thickness of 1.75 mm. Because of this, W-type hexagonal ferrites are suitable for a wide range of electronic applications, including microwave absorbers, high-density recording media, and multilayer chip inductors. These applications have made it possible to functionalize these materials in order to enhance device performance and lower the size, weight, and cost of devices while also fostering the development of new technologies that have significantly improved the quality of our daily lives.

A new hybrid non-aqueous approach for the development of Co doped Ni-Zn ferrite nanoparticles for practical applications: Cation distribution, magnetic and antibacterial studies

Ni-Zn spinel nanoferrite with a composition Ni0.6-xZn0.4CoxFe2O4 (x = 0.00, 0.033, 0.066, 0.132, 0.264 and 0.528) was produced at a low reaction temperature using a novel hybrid direct non-aqueous approach that eliminates the need for a complexing agent and a precursor that adjusts pH. The developed Ni0.567Zn0.4Co0.033Fe2O4 (x = 0.033), Ni0.534Zn0.4Co0.066Fe2O4 (x = 0.066) and Ni0.072Zn0.4Co0.528Fe2O4 (x = 0.528) nanoferrites attains the single-phase spinel cubic nano symmetry with a crystallite size of 54.91, 47.55, and 48.98 nm, respectively. Spherical shaped nanoparticles with aggregated behaviour were confirmed for the produced nanoferrites. XPS spectra of Ni0.072Zn0.4Co0.528Fe2O4 nanoferrite confirms the detection of major photoemission peaks of Zn2p, Ni2p, Co2p, Fe2p, O1s, and C1s. According to the BET research investigation, Ni0.072Zn0.4Co0.528Fe2O4 nanoferrite having specific surface area of 2.309 m2/g. The highest saturation magnetization and coercivity of 37.09 emu/g and 108.85 Oe was attained at higher doping content of cobalt (x = 0.528). With this nano crystalline nature and excellent magnetic factors, the developed nanoferrites are highly beneficial for the recording media applications to get the suitable signal to noise ratio and also, for multi-layer chip inductors (MLCIs). From the antibacterial investigation, it was observed that the produced Co doped Ni-Zn ferrites (x = 0.033, 0.264) shows high zone of inhibition (ZOI) for E. coli and Bacillus subtilis but the rest of the samples (x = 0.0, 0.066, 0.132, 0.528) shows no ZOI for both the bacterial strains. Therefore, the prepared Co doped Ni-Zn nanoferrites also works as superior antibacterial agent for biological application.

Enhanced electrical transport properties of Cr-substituted Mg2–Y-type hexaferrites for power applications

The impact of Cr3+ substitution on the electrical and dielectric properties of Y-type hexaferrites with composition Ba2Mg2CrxFe12-xO22 (x = 0.0, 0.5, 1.0, 1.5, and 2.0) was synthesized by the sol-gel auto combustion technique. The lattice parameters 'a' and 'c' slightly increase with the substitution content of Cr3+, and some other physical parameters, including porosity, microstrain, dislocation density, specific surface area, and stacking fault coefficient, were determined from XRD data. FTIR spectra confirm the formation of iron oxide base material by the appearance of three signature bands at precisely 429, 474, and 499 cm-1 due to Fe–O vibrations at octahedral and tetrahedral sites. Substituting Cr3+ at the octahedral site enhanced the room temperature DC electrical resistivity from 6.89 × 109 to 2.27 × 1010 Ω-cm. Temperature-dependent DC electrical resistivity exhibits semiconducting behavior. There is a direct relation between resistivity and activation energy. The dielectric behavior of Cr3+ substituted samples in the frequency range of 1 MHz–6 GHz was understood based on the conduction mechanism through the hopping of electrons between Fe3+ and Fe2+ ions and the Maxwell-Wagner Model. In impedance spectroscopy studied using Cole-Cole plots, most dielectric response arises from the contribution of the grain boundary effect. With the substitution of Cr3+, dielectric losses decreased. A very high Q-value around 1 GHz was observed, suggesting that these hexaferrites are efficient materials for many high-frequency applications, such as multi-layer chip inductors (MLCI), dielectric resonators, and power applications.

Structural, morphological, dielectric and ferroelectric properties of Nd substituted YFeO3 ceramics synthesized via sol gel auto-combustion route

The effect of Nd3+ ion substitution on the structural, morphological, ferroelectric, and dielectric properties of Y1-xNdxFeO3 (0 ≤ x ≤ 0.16) was investigated. The samples were prepared using the sol-gel auto-combustion route. The crystallite size was found to be in the range of 23 to 15 nm. The SEM exhibited that pure YFO shows an inhomogeneous shape of particles, while the substituted samples demonstrated a spherical shape and clusters of grains. The substitution of Nd3+ ions causes the splitting of vibrational characteristic bands υ1 from 450.71 to 479.1 cm−1 while characteristic band υ2 changes from 592.13.1 to 687.90 cm−1, respectively. The ferroelectric analysis indicated that polarization was 0.023 nC/cm2 to 0.007 nC/cm2 at a maximum applied field of 0.01 kV/cm. The dielectric constant of Nd3+ substituted YFO was increased as compared to pure YFO. All YFeO3 samples showed low values of tan loss (tanδ) es compared to pure YFO. Low dielectric losses of YFO suggest their utilization in multilayer chip inductors.

Impact of erbium substitution on structural, dielectric, spectral, and microwave absorption properties of Ba3Co2Fe24O41 Z-type hexa-ferrites for microwave devices applications

A series of erbium-substituted Z-type hexaferrites with composition Ba3Co2ErxFe24-xO41 (0.00≤ x ≤ 0.12, Δx = 0.03) was synthesized via the sol-gel auto combustion technique and sintered at 1200 °C for 5:30 h. XRD analysis confirmed the single phase crystals throughout the samples. Incorporating erbium ions into a Z-type hexagonal lattice showed improved structural parameters. The lattice parameters (a, c) exhibited an increasing trend with the rare earth (Erbium) substitution in the range of 5.884–5.891 nm and 52.561–52.770 nm. Scherrer's equation was used to find crystallite size in 28–30 nm range. Absorption bands of ferrite phase were confirmed by Fourier Transform Infrared Spectroscopy. Dielectric characteristics of synthesized materials were studied through Epsilometer R60 VNA over a frequency 1 MHz to 6 GHz range. Variations in dielectric parameters were observed by substituting erbium ion into a Z-type hexaferrite lattice. The magnitude of the dielectric constant, AC conductivity, tangent loss, and dielectric loss increases at higher frequencies. While, dielectric constant, AC conductivity, loss factor, and tangent loss decrease with Erbium substitution. The high value of Q-factor ∼10232 at 0.87 GHz was observed. The cole-cole plots in impedance analysis confirmed the character of grains and grain boundaries in the conduction mechanism. Minimum reflection loss (RL) was −67 dB for the sample x = 0.06 at 0.2 GHz. At 1.28 GHz frequency, RL = −46 dB was observed for sample x = 0.03. The morphological study (SEM) revealed the hexagonal platelet-type grains with an average grain size of 2.48–2.73 μm. Minimum reflection loss, small crystallite size <50 nm, and high-quality factor suggested that these materials are suitable candidates for microwave absorbers, resonant circuits, multi-layer chip inductors, and high-frequency devices.

Investigation of crystal structure, electrical and dielectric response of Ga3+ substituted Sr–Ni Y-type hexaferrites as a suitable material for high frequency applications

Technology important ferrites ceramic Sr2Ni2GaxFe12-xO22 (x = 0.00, 0.2, 0.4, 0.6, and 0.8) samples were produced using sol-gel auto combustion route. Structural, electrical, dielectric, and magnetic parameters were identified by substituting Ga3+ at the Fe3+ site. It was recognized that an increase of Ga3+ content in (Sr2Ni2GaxFe12-xO22) ceramic samples first decreased, then increased lattice parameters, and the density of samples was observed. This is because of the ionic radii and atomic weight of Ga3+ and Fe3+ cations. FTIR spectra show two characteristic absorption bands at 444-513 cm−1 caused by metal-oxygen vibrations. Due to the contribution of smaller grains of samples, the higher values of resistivity were observed, which vary from 3.78 × 1010 (Ω cm) to 1.13 × 1011 (Ω cm) by the substitution of Ga3+ ions at the octahedral site. The activation energy was measured between 0.20 and 0.61 eV. The dielectric response of Ga3+ substituted ferrite ceramic samples were studied in the 1 MHz-6 GHz frequency region. The Maxwell-Wagner bilayer model studied the effect of polarization with applied frequency on dielectric parameters. With the substitution of Ga3+, minimal losses in the range 0.34–0.44, about 6 GHz, and a high Q-value of about 10,000 were observed for each sample. In impedance spectroscopy analysis Cole-Cole plots confirm that the dielectric response is because of the influence of grain boundaries. The substitution of Ga3+ enhances saturation magnetization (68.20–71.78 emu/g) while coercivity decreases (655.86–507.86 Oe). In the present finding, the low dielectric loss, moderate permittivity, high value of the Quality factor, and very high value of resistivity of about 1.13 × 1011 that reduces the eddy current losses suggested that these materials are appropriate candidates for many high-frequency applications such as multilayer chip inductor, dielectric resonators, power applications, and microwave devices.

Preparation and electromagnetic properties of NiCuZn ferrites and multilayer chip inductors

(Ni0.2Cu0.2Zn0.6O)1.02(Fe2O3)0.98 based ferrites with combined B2O3-WO3-Co2O3 dopings were synthesized through solid state reaction. Subsequently, high-performance NiCuZn green tapes and multilayer chip inductors were fabricated via non-aquous tape casting. The results showed that an appropriate Co2O3 doping in the B2O3-WO3 contained NiCuZn ferrites could refine the crystalline grains, and reduce the permeability, and increase the Q factor of the ferrites. NiCuZn ferrite with 0.03 wt% B2O3, 0.7 wt% WO3, and 0.60 wt% Co2O3 sintered at 900 °C showed excellent electromagnetic properties: μi = 424.0 at 0.1 MHz, Q factor = 127.0, Bs = 283.5, Br = 79.5, Hc = 52.3, and a good co-firing compatibility with Ag electrodes. The resulting NiCuZn multilayer chip inductor (6 ×6 ×2 mm in dimention) exhibited an inductance of 26.0 μH (0.1 MHz, 0.25 V), and a Q factor of 8.5, and a DC superposition current of about 984 mA, thus guaranteeing this NiCuZn material a promising candidate for the LTCF applications.

A comprehensive study on structural, magnetic and dielectric properties of Ni0.3Cu0.3Zn0.4Fe1.8Cr0.2O4 nanoparticles synthesized by sol-gel auto combustion route

Ni0.3Cu0.3Zn0.4Fe1.8Cr0.2O4 (NCZF) ferrite nanoparticles (NPs) were prepared by sol-gel auto-combustion route. As obtained NCZF powder NPs from sol-get auto combustion route were divided into four parts equally. A non-calcinated part of NCZF NPs was considered as SS1 sample, whereas the three separated parts of NCZF NPs were calcinated at 400°C, 600°C and 800°C, accordingly and were considered as SS2, SS3 and SS4 samples, respectively. X-ray diffraction (XRD) patterns of as-prepared samples were used to evaluate the microstructure parameters. The obtained crystallite sizes were found to be 25, 26.5, 23.4 and 28.1 nm for SS1, SS2, SS3, and SS4 samples, respectively. Transmission electron microscopy images of samples exhibit the spherical shape particles. Average particle size was found to be 6.18, 8.24, 12.7, and 17.14 nm from particles size distributions of SS1, SS2, SS3 and SS4 samples, respectively. The saturation magnetization MS(45.96, 49.84, 48.84 and 50.01 (emu/g), coercivityHC(41.40, 43.00, 44.06, and 43.69 Oe), and remanant magnetization Mr(2.00, 1.85, 1.88 and 1.92 emu/g) were determined from M-H analysis of as-prepared samples. Surface analysis of SS2, SS3 and SS4 samples were examined by X-ray photoemission spectroscopy. Dielectric properties and real value of electric modulus of SS4 sample were reduced drastically as-compared to SS2 sample. Frequency dependent conductivity and impedance of SS4 sample was enhanced as-compared to SS2. Outstanding structural, dielectric and electric, and magnetic properties of NCZF NPs can be used for the multi-layer chip inductor applications.

Optimization of structural, electrical, and magnetic properties of ytterbium substituted W-type hexaferrite for multi-layer chip inductors

The rare earth (Yb3+) substituted W-type hexagonal ferrites with composition CaPb2-xYbxFe16O27 (x = 0.0, 0.5, 1.0, 1.5, 2.0) were synthesized by a facile and cost-effective sol-gel auto combustion method with post heat treatment. The synthesized hexagonal ferrites were characterized by a variety of analytical techniques, and an impedance analyzer was used to investigate the effects of Ytterbium on structural, magnetic, spectral and dielectric properties. The relationship between their impedance, structure and dielectric properties was investigated. The X-ray diffraction patterns verify the presence of single-phase W-type hexagonal ferrites. Physical properties such as Dbulk (bulk density), Dxrd (X-ray density), and P (porosity) of the CaPb2-xYbxFe16O27 W-type hexagonal ferrites were calculated. The bulk density of all the samples was decreased, and X-ray intensity was increased with the Ytterbium replacement in the W-type hexaferrite. By adding Yb3+ ions, the lattice parameters, cell volume and X-ray density were reduced due to the substitution of ytterbium with smaller ionic radii compared to the lead ion with large ionic radii. The AC-conductivity was increased from (1.523 × 10−5 to 6.699 × 10−5) Ωcm−1. The dielectric constant and tangent loss was found to decrease substantially. The magnetic properties were found to enhance by the substitution of Yb3+. The low coercivity value of Yb3+ substituted W-type hexagonal ferrites are suitable for magnetic recording media operated at a high-frequency regime. The enhancement of electrical, dielectric and magnetic characteristics suggests these materials as promising for multi-layer chip inductors (MLCIs) circuit applications.

Enhanced Structural and Dielectric Properties of Calcium and Chromium-Based M-Type Hexagonal Ferrites with Polyvinyl Alcohol (PVA) Polymer Composites

[Formula: see text]-type hexagonal ferrites with compositions Ca[Formula: see text]CrxFe[Formula: see text]O[Formula: see text] at ([Formula: see text], 0.2, 0.3, 0.4, 0.5) were successfully prepared by sol–gel auto combustion method and then immersed with polyvinyl alcohol (PVA) by ultrasound-assisted in situ emulsion technique. The results indicate that the synthesized nanoparticles were diffused homogeneously in PVA retaining the size and shape of the particle. The single-phase [Formula: see text]-type hexagonal structure was revealed by X-ray diffraction (XRD) with extra 101 peak of PVA at 2[Formula: see text]. The suitable signal-to-noise ratio in the high density recording media can be achieved due to the small particle size of the prepared composites as compared to pure hexaferrites. The interaction between PVA and nanoparticles was confirmed by Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) images revealed the homogeneous distribution of grains, the crystallite size was measured from SEM (25–38[Formula: see text]nm), and it is also in agreement as calculated from the Scherer formula. Dielectric properties were also explored in the range of 1 MHz–3 GHz frequencies. Dielectric constant and dielectric loss were found to decrease with increasing frequency and decrease with the addition of ferrite ratio in the polymer matrix. This impact is because of the grain boundary at low frequency regime. The occurrence of resonance at high frequency regime recommends the investigated samples for multilayer chip inductor.

Structural, Morphological, Dielectric, and Magnetic Properties of Pb1-xCrxFe12O19 M-type Hexaferrites

Chromium substituted M-type hexagonal ferrites with nominal composition Pb1-xCrxFe12O19 where x= (0.0, 0.1, 0.2, 0.3, 0.4, 0.5) were prepared via sol gel route. Structure of the single phase lead hexaferrite was estimated from X-ray diffraction (XRD) analysis. Scanning electron microscopy (SEM) confirmed the formation of hexagonal platelets with an average grain size in the range of 53–63 nm. Crystallite size, lattice parameters and cell volume was found to decrease with the increase of Chromium concentration. Magneto crystalline anisotropy and saturation magnetization has been explored through the law of approach to the saturation magnetization. Saturation magnetization first increased and then found to be maximum (64 emu/g) at 30% of Cr3+ doped lead hexaferrite and minimum coercivity (6.54 KOe) was perceived for this composition. Dielectric constant, dielectric loss, tangent loss, real and imaginary part of electric modulus, ac conductivity and Q-values of the prepared samples were also explained. With the increase of dopant (Cr3+) concentration, dielectric constant was increased gradually. These characteristics are suitable for various applications such as phase shifter, modulators, stealth technologies and also in Multilayer chip inductor.

Impact of cadmium substitution on the structural, spectral, dielectric and magnetic properties of Z-type hexaferrites synthesized via sol-gel route

Cadmium substituted Z-type hexaferrites are prepared via the sol-gel route. The phase temperature of pre-sintered materials is studied from the thermal analysis. The single-phase of Z-type hexaferrite is found through X-ray diffraction investigation. The Crystallite sizes of the entire samples are evaluated within the range of 14–15 nm. The Fe–O stretching vibration band at 566 cm−1 is confirmed from Fourier transform infrared spectroscopy. Saturation magnetization (Ms) coercivity (Hc) and remanence (Mr) is examined by a vibrating sample magnetometer. The magnitude of Ms has been increased from 45.41 to 56.35 emu/g with an increase of Cd2+ concentration. The magnitude of Hc increased from 950.79 to 2186.95 Oe with an increment of Cd2+ concentration. Small values of squareness ratio (less than 0.5) showed the hard and single magnetic domain nature of the materials. The dielectric properties were analyzed using an impedance analyzer. Dielectric parameters show an increasing trend with the substitution of Cd2+. The maximum values of quality factor up to 17,000 and 10,000 are observed for sample Ba2·85Cd0·15Co2Fe24O41 at 1 GHz and 2.7 GHz, respectively. The high value of the Q-factor shows that these ferrites can be applicable for the formation of resonant circuits and multilayer chip inductors.

Influence of Calcination Temperature on Microstructure and Properties of (NiCuZn)Fe2O4 Ferrite Prepared via Ultrasonic-Assisted Co-Precipitation

(NiCuZn)Fe2O4 ferrite is a kind of soft magnetic material widely used in multilayer chip inductors because of its high resistivity and excellent magnetic properties at high frequencies. In this study, (Ni0.4Cu0.2Zn0.4)Fe2O4 ferrite powder was prepared by ultrasonic-assisted chemical co-precipitation method, the effect of calcination temperature on the structure and properties of ferrite powders was investigated by modern analytical methods that include differential thermal analysis, X-ray diffraction, transmission electron microscopy, infrared spectroscopy, and vibrating sample magnetometer, respectively. The results show that the grain size increased from 23.5 nm to 38.6 nm and the lattice size increased from 8.384 A to 8.390 A with the increase of calcination temperature from 600°C to 900°C. The TEM shows that the powder particle was uniform and dispersible, and the particle size was about 30nm at 800°C calcination. The saturation magnetization of ferrite powder increases from 45.85emu/g to 50.65emu/g and the coercivity decreases from 65.50Oe to 46.23Oe with the increase of calcination temperature from 700°C to 900°C. The uniform and fine nano-crystalline ferrite particles would reduce the sintering temperature and improve the stability of the properties for spinel ferrite. The preparation of nano-spinel ferrite by ultrasonic-assisted co-precipitation is a worthy wet process for application.