Magnetic and microwave absorption properties of La3+-substituted manganese ferrites synthesized via solid-state reaction method

La3+-substituted manganese ferrites with chemical formula MnLaxFe(2−x)O4 (0 ≤ x ≤ 0.03) were prepared via solid -state reaction method. X-ray diffraction (XRD) analysis with Rietveld refinement method confirmed that all compositions exhibited a single-phase formation of manganese ferrite (MnFe2O4, cubic (Fd−3 m)). The lattice parameters were found to decrease with increasing La3+ ion substitution from 8.505 Å (x = 0) to 8.485 Å (x = 0.03). The substitution process was found to induce the lattice strain and hinder the crystallite growth in the La3+-doped samples. The particle size distribution curve of the La3+-substituted samples was shifted to smaller size compared to the original sample. Magnetic properties measurement was carried out to reveal the magnetic parameters such as saturation magnetization (Ms), remanence magnetization (Mr), and field coercivity (Hc). The Ms was determined from the law of approach to saturation (LAS) method. As the results, we found that the Ms values were decreased from 17.56 emu/g (x = 0) to 7.09 emu/g (x = 0.03), while the Hc values were increased from 126.50 Oe (x = 0) to 202.00 Oe (x = 0.03). The microwave absorbing property of all MnLaxFe(2−x)O4 (x = 0.0; 0.01; 0.02 and 0.03) series was measured in X-band frequency range (8–12 GHz). The results showed that the substitution of La3+ ion was responsible to the improvement of the microwave absorbing ability with the attenuation of microwave which was increased from 91.57 to 97.61%. Thus, the composition with x = 0.03 (MnLa0.03Fe1.97O4) showed an excellent response and can be considered as microwave absorbing material candidate.