Dielectric and magnetic properties of new rare-earth substituted Ba- hexaferrites in the 2-18 GHz frequency range

摘要

Rare-earth substituted M-type barium hexaferrites with nominal formula (Ba_(1-x)RE_x)O·5.25(Fe_2O_3), with RE = Dy or Gd (x = 0-0.20), were prepared by the chemical coprecipitation method. Complex permittivity ε~*_r and permeability μ~*_r of HDPE-ferrite composites were measured with the coaxial line method in the 2-18 GHz frequency range. The electromagnetic behavior of the composites was correlated to dielectric polarization and magnetic interactions mechanisms, on the basis of the ferrite's physical and structural characteristics. The results show dissimilar effects on the microwave properties of the composites, that may be ascribed to different structural and physical configurations of the Dy-and Gd-substituted hexaferrites.