LAUSR

Mg0.2Mn0.8HoxFe2−xO4 (x = 0.025, 0.050, 0.075 and 0.100) nanocrystalline is synthesized via a hydrothermal technique. Single phase cubic spinel is confirmed by XRD and the formation of Mg0.2Mn0.8HoxFe2−xO4 is verified by EDS. The average size for the nanoferrites is around 80 nm which is examined by TEM with the presence of agglomerated particles. Ho3+ substituted Mg-Mn nanoferrites exhibit the low saturation magnetization (M s ) and coercivity (H c ). Especially, with x = 0.100, the nanoferrites show the lowest M s and H c of 46.850 emu g−1 and 46 Oe, respectively. The ferrite composites present the dielectric dissipation less than 0.37 and the magnetic loss less than 0.46 at 2–18 GHz. The low saturation magnetization, low coercivity and low dielectric dissipation indicate that the addition of Ho3+ contributes to synthesize better soft magnetic materials.