Influence of the iron content on the formation process of substituted Co-Nd strontium hexaferrite prepared by the citrate precursor method

摘要

Strontium hexaferrite samples of different composition were prepared by the self-combustion method and heat-treated in air at 1100℃ for 2h: SrFe_(12)O_(19) (SO), Sr_(0.7)Nd_(0.3)Fe_(11.7)Co_(0.3)O_(19) (SS), Sr_(0.7)Nd_(0.3)Fe_(10.7)Co_(0.3)O_(19) (SM) and Sr_(0.7)Nd_(0.3)Fe_(8.4)Co_(0.3)O_(19) (SL).The phase identification of the powders was performed using XRD. Only sample SL (with the lowest iron concentration) shows well-defined peaks of the hexaferrite phase with no secondary phases. Nd-Co substitution modifies saturation magnetization (M_s) and coercivity (H_c) but only samples with low Fe~(3+) content (SL and SM) show the best magnetic properties, indicating that the best results for applications of this ferrite will be obtained with an iron deficiency in the stoichiometric formulation.