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

Strontium hexaferrite samples of different composition were prepared by the self-combustion method and heat-treated in air at 1100 degrees C for 2h center dot SrFe12O19 (SO), Sr0 7Nd0 3Fet 1 7Co0 3O19 (SS). Sr0 7Nd0 3Fe10 7Co0 3O19 (SM) and Sr0 7Nd0.3Fe8 4Co0 3O19 (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 Fe3+ 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. (C) 2009 Elsevier B V All rights reserved