Figure 3.

Characterization of MNPs and HAp-MNPs. (A) TEM micrographs. MNPs are indicated with arrowheads, and HAps with arrow marks. (B) FTIR analysis. Indicated peaks: a: OH⁻ ion stretching (3500-3100 cm⁻¹); b: ${{\text{CO}}_3}^{2-}$ (1350 and 1650 cm⁻¹); c: ${{\text{PO}}_4}^{3-}$(1045 and 1087 cm⁻¹, and P–O bending at 550-650 cm⁻¹); d: Fe–O vibration (570 cm⁻¹). (C) Magnetization curves.