NiZnCo ferrite has a wide range of applications in high-frequency devices, but its performance can be further improved to meet more requirements. In this work, Sc 3+ -substituted Ni 0.5 Zn 0.4 Co 0.1 Sc x Fe 2-x O 4 (NZCScF, 0 ≤ x ≤ 0.1) ferrite soft magnetic materials were successfully prepared by sol–gel self-propagating approach. After using Sc 3+ doping, the dielectric loss and dielectric constant are significantly reduced. The intensity of the coercive field decreases significantly with a rise in the Sc 3+ content. It is noteworthy that after adding Sc 3+ ions, the saturation magnetization can reach 94.27 emu/g, an increase of about 27%, and the initial permeability is increased by about 73%. In the high-frequency scope, the magnetic losses increase very little and up to 100 MHz the magnetic losses remain low. In conclusion, Sc 3+ substitution effectively improves the electromagnetic properties of NiZnCo ferrite and greatly enhances the saturation magnetization and initial permeability. It can serve as a guide for the material application of a series of high-frequency devices such as radio-frequency microwave devices.
Fang Xu,Yan Yang,Yonggang Liu,Jing Yang,Yulong Liao,Xueying Wang,Xiaolei Shi,Jianbo Hu
Improving magnetic-dielectric properties of polymer materials, through filler of functional ceramics , provides feasibility to develop high-frequency flexible electronics. Poly-dimethylsiloxane (PDMS), an inert silicone with low elasticity modulus and high transparency, has been considered a promising candidate for flexible electronics. Current PDMS matrix used in high-frequency devices suffers from unsatisfactory properties due to very low dielectric constant. In this study, using ultrasonic stirring and vacuum-pumping process, we prepare a series of xCo 2 Z/PDMS (x = 2; 4; 6; 8; 10) composite films , which are consisted of PDMS matrix and different quantity of micro-sized ferrite particles. XRD pattern indicates that the obtained ferrite particles include Co 2 Z main phase and BaM second phase. We demonstrate that 4Co 2 Z/PDMS film has improved magnetic-dielectric properties at 800 MHz (μ' = 1.49; ε' = 4.54 tanδ μ = 0.058; tanδ ε = 0.008). Also, the film has high saturation magnetization ( σ s = 17.51 emu/g). Furthermore, SEM micrographs show that using ultrasonic stirring and fast curing, the micro-sized ferrite particles are well dispersed in PDMS matrix. Our study, which provides a simple method to improve high-frequency magnetic and dielectric properties of PDMS matrix, could pave the way for development of high-frequency flexible electronics.
Jingyu Yuan,Jie Li,Yang Xiao,Xinyi Zhu,Siyuan Wang,Yan Yang,Jinliang Zou,Yichao Yan
In this work, In-doped LiZnTi spinel ferrites were successfully synthesized at a low temperature (920 °C) using 2 wt% Bi 2 O 3 as a sintering aid. The effects of In 3+ doping concentration on phase formation, microstructure, gyromagnetic properties, and dielectric properties were investigated. Results showed that all samples exhibited a single spinel phase, and grain growth behavior was strongly influenced by In 3+ doping. Although saturation magnetization decreased with increasing In 3+ content, the real part of the magnetic permeability (μ') increased from 117 (x = 0.00) to 170 (x = 0.09), while maintaining low magnetic loss. Meanwhile, the dielectric constant showed an upward trend (ε' increased from 15.88 to 18.50) with minimal dielectric loss. Regarding gyromagnetic properties, the sample with x = 0.06 exhibited a narrow ferromagnetic resonance linewidth (ΔH) of 240.09 Oe. The combination of high dielectric constant and low linewidth suggests promising potential for low-loss microwave ferrite devices.
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