Magnetic and dielectric properties of the M-type barium strontium hexaferrite (BaxSr1−xFe12O19) in the RF and microwave (MW) frequency range

This paper presents results for the dielectric permittivity (e′), dielectric loss (tg δ E) dielectric permeability (μ′) and magnetic loss (tg δ M) in the radio-frequency and microwave frequency range of Ba x Sr1−x Fe12O19 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 (BaFe12O19) and 1.16 < μ′ ≤ 1.88 for SFO100 (SrFe12O19) 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 of 33–36 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.