Synthesis and Characterization of Iron–Sillenite for Application as an XRD/MRI Dual-Contrast Agent

In the present work, iron–sillenite (Bi₂₅FeO₄₀) was synthesized using a simple solid-state reaction method and characterized. The effects of the synthesis conditions on the phase purity of Bi₂O₃/Fe₃O₄, morphological features, and possible application as an XRD/MRI dual-contrast agent were investigated. For the synthesis, the stoichiometric amounts of Bi₂O₃ and Fe₃O₄ were mixed and subsequently milled in a planetary ball mill for 10 min with a speed of 300 rpm. The milled mixture was calcined at various temperatures (550 (Formula presented.) C, 700 (Formula presented.) C, 750 (Formula presented.) C, 800 (Formula presented.) C, and 850 (Formula presented.) C) for 1 h in air at a heating rate of 5 °C/min. For phase identification, powder X-ray diffraction (XRD) analysis was performed and infrared (FTIR) spectra were recorded. The surface morphology of synthesized samples was studied by field-emission scanning electron microscopy (FE-SEM). For the radiopacity measurements, iron–sillenite specimens were synthesized at different temperatures and mixed with different amounts of BaSO₄ and Laponite solution. It was demonstrated that iron–sillenite Bi₂₅FeO₄₀ possessed sufficient radiopacity and could be a potential candidate to meet the requirements of its application as an XRD/MRI dual-contrast agent.