Synthesis of Fe 3 O 4 and Mn 0.25 Fe 2.75 O 4 using natural iron sand: its analysis on crystal structure and size

Abstract Understanding crystal size is crucial to optimize the desired properties, such as photo-Fenton activity, which is superior with nano-sized materials compared to bulk materials. This study aimed to investigate the crystallographic properties of Fe3O4 and Fe3O4 substituted with Mn 2+ ions (Mn 0.25 Fe 2.75 O 4 ). Fe 3 O 4 and Mn 0.25 Fe 2.75 O 4 were synthesized from natural iron sand, which is abundant in Indonesia, where the synthesis followed the coprecipitation route. X-Ray Diffraction (XRD) characterization was performed to confirm their crystal structure and size. The crystal size was further analyzed by Scherrer, Monshi-Scherrer, Williamson-Hall (all of uniform deformation model, uniform stress deformation model, and uniform deformation energy density model), Size-Strain Plot, and Halder-Wagner models. XRD analysis revealed that the crystal structures of Fe 3 O 4 and Mn 0.25 Fe 2.75 O 4 are inverse spinel. The Mn 0.25 Fe 2.75 O 4 crystal shows a larger crystal size than Fe 3 O 4 . All models show accurate results except Halder-Wagner, which makes a significant difference.