Phase evolution and magnetodielectric properties of Ba3Co2Fe24O41 hexaferrite after Bi2O3 incorporation

Ba₃Co₂Fe₂₄O₄₁ (Co₂Z) is a hexagonal ferrite material in which achieving synergistic control of magnetic and dielectric properties in the MHz–GHz range remains a key challenge. This study explores the modulation of these properties in Co₂Z through doping with highly polarizable Bi^3 + ions. A combination of experimental analysis and first-principles calculations was used to investigate the effects of Bi³⁺ doping on phase evolution, crystal structure, magnetic behavior, and dielectric response. The results show that Bi³⁺ incorporation effectively lowers the synthesis temperature of the Z phase to approximately 1150°C and enhances both the magnetic permeability and permittivity of Co₂Z. At a doping level of x = 0.3, Co₂Z exhibits optimal impedance matching and a notable miniaturization factor for antenna substrates operating in the MHz–GHz range. These findings provide theoretical insights and practical guidance for the design of high-performance Co₂Z-based materials for advanced antenna applications.