Magnetic and dielectric properties of the M-type barium strontium hexaferrite (Ba x Sr1−x Fe12O19) in the RF and microwave (MW) frequency range

Abstract

This paper presents results for the dielectric permittivity (e′), dielectric loss (tg δE) dielectric permeability (μ′) and magnetic loss (tg δM) in the radio-frequency and microwave frequency range of BaxSr1−xFe12O19 hexaferrite (0 ≤ x ≤ 1). The samples were prepared by a new route of the ceramic method. The magnetic permeability (μ′) and magnetic loss (tg δM) 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 δM = 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.