Tuning of Structural, Dielectric, and Electronic Properties of Cu Doped Co–Zn Ferrite Nanoparticles for Multilayer Inductor Chip Applications

Abstract

Herein, we report the synthesis of nanoparticles and doping of Cu-doped Co–Zn ferrites using the auto-combustion sol–gel synthesis technique. X-ray diffraction studies confirmed the single-phase structure of the samples with space group Fd3m and crystallite size in the range of 20.57–32.69 nm. Transmission electron microscopy micrographs and selected area electron diffraction patterns confirmed the polycrystalline nature of the ferrite nanoparticles. Energy-dispersive X-ray spectroscopy revealed the elemental composition in the absence of any impurity phases. Fourier-transform infrared studies showed the presence of two prominent peaks at approximately 420 cm−1 and 580 cm−1, showing metal–oxygen stretching and the formation of ferrite composite. X-ray photoelectron spectroscopy was employed to determine the oxidation states of Fe, Co, Zn, and Cu and O vacancies based on which cationic distributions at tetrahedral and octahedral sites are proposed. Dielectric spectroscopy showed that the samples exhibit Maxwell–Wagner interfacial polarization, which decreases as the frequency of the applied field increases. The dielectric loss of the samples was less than 1, confirming that the samples can be used for the fabrication of multilayer inductor chips. The ac conductivity of the samples increased with increasing doping and with frequency, and this has been explained by the hopping model. The hysteresis loops revealed that coercivity decreases slightly with doping, while the highest saturation magnetization of 55.61 emu/g was obtained when x = 0.1. The magnetic anisotropic constant was found to be less than 0.5, which suggests that the samples exhibit uniaxial anisotropy rather than cubic anisotropy. The squareness ratio indicates that the samples are useful in high-frequency applications.

Structural, Dielectric, and Magnetic Properties of SCS-Produced Copper Zinc Nanoferrites

“…Furthermore, the dielectric constant increased with increasing x, thus showing that the hopping of charges between the charge carriers, which was initially between Fe 3+ and Fe 2+ , was further supported by the hopping of charges between the Cu 1+ and Cu 2+ state [21]. This is because of decline in resistivity (decrease in Zn concentration) which increases the probably for electrons to reach the grain boundary, which intensifies polarization and hence increases the dielectric constant [23,24].…”

“…The charges are often separated over a considerable distance and the contribution to dielectric loss can therefore be orders of magnitude larger than the dielectric response due to molecular fluctuations. The dissipation of power in material is directly proportional to dielectric loss factor [16][17][18][19][20][21][22][23][24].…”

“…At higher ω, the hopping cannot follow the applied field and lags behind, thus leading to a decrease in σ. Such a behavior can be related to the relaxation process caused by the domain reorientation, domain wall motion, and dipolar behavior [23][24][25].…”

Investigating the Impact of Cu2+ Doping on the Morphological, Structural, Optical, and Electrical Properties of CoFe2O4 Nanoparticles for Use in Electrical Devices

“…Numerous studies [ 8 , 9 , 22 , 23 ] have been conducted on smaller amounts of Cu doping, where an increase in Cu 2+ concentration resulted in structural modifications with increased electrical characteristics and decreased magnetic features of materials. Jnaneshwara et al [ 24 ] fabricated Co 1− x Cu x Fe 2 O 4 with x = 0 to 0.5 using an auto-combustion route and revealed a decrease in the magnetization saturation value from 38.5 to 26.7 emu/g with an increase in Cu 2+ concentration.…”

Study of PVDF/ (Co-ZnFe2O4 and Cu-ZnFe2O4) nanocomposite for the piezo-phototronics applications

“…The greater dielectric values were observed in case of (Co-ZnFe2O4) nanofiller where it increases the dielectric constant from 0.05 for neat PVDF to 2. These greater dielectric values resulted from the interfacial polarizations at the conductor-insulator interface [34] [35] [36]. As well as the PVDF dielectric loss increases by the addition of the nanoparticles, the higher increase was observed in the PVDF/Cu-Zn Fe2O4 sample this increase is attributed to the increase in n and K with the nanofillers.…”