Microstructural and high-frequency magnetic characteristics of W-type barium ferrites doped with V2O5

Abstract

The microstructure, static, and dynamic magnetic properties have been investigated for BaCoZnFe 16 O 27 doped with small amounts of V 2 O 5 from 0 to 1.5 wt %. The results show that the doping of V 2 O 5 can significantly improve the dynamic properties of W-type barium ferrites at microwave frequency. As compared to the undoped sample, the permeabilities 0 Ј and max Љ increase by about 42% and 67%, respectively, for the sample doped with 1.0 wt % of V 2 O 5 . Due to the V 2 O 5 doping, perfect hexagonal-plate grains are formed, leading to the decrease in the natural resonance frequency, due to the large demagnetizing effect. The predicted reflection loss shows that the maximum relative bandwidth W max = f up / f low reaches 3.9 for attenuation of more than 10 dB in the sample doped with 1.0 wt % of V 2 O 5 . This is a good candidate for electromagnetic materials with low reflectivity and broadband at microwave frequency.

Dielectric and magnetic behavior of BaCd2−xSrxFe16O27 W-type hexagonal ferrites

“…The values of complex permittivity "ε" for each composition decrease further with the increase of frequency up to 10 5 Hz and become constant at higher frequency as shown in Fig. 6(a) and (b), which is in the agreement with the results for the W-type hexagonal ferrites [2]. This can be attributed to the fact that the dielectric properties of polycrystalline ferrite arise due to the interfacial polarization.…”

“…Electromagnetic (EM) materials, which usually consist of dielectric or magnetic fillers and polymers, are commonly used to minimize EMI [2]. Ferrites show significant magnetic losses at ferromagnetic resonance (FMR) position.…”

Structure and electromagnetic behavior of BaFe12−2x(Ni0.8Ti0.7)xO19−0.8x in the 2–12GHz frequency range

“…rites based on doped small amounts of oxides [4][5][6][7][8]. In addition, the substitution of other ions for some Fe 3+ ions is also an effective method to vary the magnetic properties and electrical properties of ferrites [9][10][11].…”

W-type hexaferrite nanoparticles: A consideration for microwave attenuation at wide frequency band of 0.5–10GHz

“…Therefore, the observed large values of for these samples are due to the enhancement of resultant magnetic moments along the c-axis. The broad absorption peaks for all the samples studied here in a range of 2-7 GHz is perhaps due to the presence of both natural resonance and wall resonance simultaneously and are characteristics of polycrystalline ferrites [30]. The anomalous behavior of samples having Al-Ce contents of y = 0.2 and y = 0.8 at frequencies of 6 GHz and 7.5 GHz are perhaps due to the relaxation phenomenon associated with the rare earth ion Ce 3+ .…”