Fig. 6. The ZFC–FC curves for the rHGO (panels a–d) and rIGO (panels e–h) composites with increased loading of CoFe₂O₄. Reference data for the pure CoFe₂O₄ powder are shown in panel (i). The average blocking temperature (T_B), which is the peak of the ZFC curve, is indicated by an arrow in panel (a).