Microwave ferromagnetic resonance of cobalt and nickel substituted U-type hexaferrites

Ba₄Co₂Fe₃₆O₆₀ and Ba₄Ni₂Fe₃₆O₆₀ are prepared using coprecipitation and consequent calcination. Samples are prepared such that they fit exactly into rectangular waveguide shims. The scattering parameters on the samples are determined using vector network analyzer after TRL calibration. The complex permittivity and permeability are then solved analytically from the measured parameters using Weir´s equations. Microwave properties of such Cu and Ni substituted U-type hexaferrites are investigated for the first time.