Magnetic And Dielectric Properties Of The M-type Barium Strontium Hexaferrite (ba_xsr_(1-x)fe_(12)o_(19)) In The Rf And Microwave (mw) Frequency Range

摘要

This paper presents results for the dielectric permittivity (ε'), dielectric loss (tg δ_E) dielectric permeability (μ') and magnetic loss (tg δ_M) in the radio-frequency and microwave frequency range of Ba_xSr_(1-x)Fe_(12)O_(19) hexaferrite (0 ≤ x≤ 1). The samples were prepared by a new route of the ceramic method. The magnetic permeability (μ') and magnetic loss (tg δ_M) measurements in the range 100 MHz to 1.5 GHz, reveals that 1.32 ≤ μ' ≤ 1.68 for the permeability of BFO100 (BaFe_(12)O_(19)) and 1.16 ≤ μ' ≤ 1.88 for SFO100 (SrFe_(12)O_(19)) in the range of studied frequencies. The BFO100 sample presented lower loss (tg δ_M = 4.10~(-3) at 1.5 GHz). The permittivity of BFO100 and SFO100 in 1.5 GHz are, respectively 8.18 and 8.19, and in the 1 MHz are, respectively 52.04 and 19.09. The samples presented coercive field in the range of 3-5 kOe and remanence magnetization in the range ofrn33-36 emu/g. The subjects of paper were study the dielectric and magnetic properties of the barium and strontium hexaferrite, in view of applications as a material for permanent magnets, high density magnetic recording and microwave devices.