摘要
The Z-type ferrites of nominal composition Ba3Co2 Fe24O41+x wt% Bi2O3, where x=0.25, 0.5, 1.0, 1.5, 2.0, were prepared by conventional ceramic processes. The influence of Bi2O3 content on the bulk densities, microstructures, magnetic and dielectric properties of Z-type ferrite samples were systematically examined so as to obtain materials with low magnetic and dielectric loss tangent over a frequency ranging from 600 to 800 MHz. The experimental results showed that addition of Bi2O3 lowered the sintering temperature(1 020 ℃) and then reduced the average grain size(<2 μm) and enhanced the resistivity(>2.68×10^8 Ω·cm) dramatically, which consequently decreased the magnetic and dielectric loss. Additionally, the low loss factors were observed at the Bi2O3 content x = 1.0, i e, tan δμ/μ’=0.013 and tan δε/ε’= 0.001 at 800 MHz, and such materials could be used for antennas miniaturization from 600 to 800 MHz.
The Z-type ferrites of nominal composition Ba3Co2 Fe24O41+x wt% Bi2O3, where x=0.25, 0.5, 1.0, 1.5, 2.0, were prepared by conventional ceramic processes. The influence of Bi2O3 content on the bulk densities, microstructures, magnetic and dielectric properties of Z-type ferrite samples were systematically examined so as to obtain materials with low magnetic and dielectric loss tangent over a frequency ranging from 600 to 800 MHz. The experimental results showed that addition of Bi2O3 lowered the sintering temperature（1 020 ℃） and then reduced the average grain size（<2 μm） and enhanced the resistivity（>2.68×108 Ω·cm） dramatically, which consequently decreased the magnetic and dielectric loss. Additionally, the low loss factors were observed at the Bi2O3 content x = 1.0, i e, tan δμ/μ’ = 0.013 and tan δε/ε’ = 0.001 at 800 MHz, and such materials could be used for antennas miniaturization from 600 to 800 MHz.
基金
Funded by the National Natural Science Foundation of China(No.U1435209)
Wuhan Science and Technology Program(No.2014010101010018)
Fundamental Research Funds for the Central Universities(No.2015ZZGH007)
