Manganese ferrite nanoparticles with different concentrations: Preparation and magnetism

MnFe₂O₄ nanoparticles were synthesized by thermal decomposition of a metal–organic salt in organic solvent with a high boiling point. Some nanoparticles exhibited the triangular shape which has not been observed before as far as we know, while some nanoparticles formed the aggregates with different sizes and shapes. The strength of interparticle dipolar interaction was changed by diluting MnFe₂O₄ nanoparticles in the SiO₂ matrix with different concentrations. The strong dipolar interaction has been suggested to enhance the blocking temperature (T_B) and suppress the remanence (M_r) to saturation (M_s) magnetization ratio (M_r/M_s) for the spherical-like cobalt ferrite nanoparticles in many previous reports. However, M_r/M_s and T_B of MnFe₂O₄ nanoparticles reported herein mainly depend on the size and shape of the nanoparticles and their aggregates.