The effect of pH values on the phase formation and properties of BaFe12O19 prepared by citrate–EDTA complexing method

Barium hexaferrites (BaFe12O19) have been prepared by citrate–EDTA complexing method using citrate and EDTA as complexing chelating agents with various pH values. Complexation stability constant analysis, XRD patterns and SEM investigations all display that the chelation between metallic ions and ligand may reach an excellent degree in the condition of pH 6. The precursor with more uniformly distributed Fe3+ and Ba2+ can convert to hexagonal barium ferrite more easily and completely. A network analyzer (Agilent 8722ET) was employed to determine the electromagnetic parameters of ɛ′, ɛ″, μ′, and μ″ at the frequency range of 2–18 GHz by a reflection/transmission technique. The sample of pH 6 has lowest permittivity (ɛ′ = 1–3, ɛ″ ≈ 0) and highest permeability (μ′ = 1.5–3.5, μ″ = 0.5–2.5), exhibiting excellent microwave performances.