Applied in magnetic resonance imaging (MRI) as contrast agents for enhanced tissue visualization, targeted hyperthermia cancer therapy using alternating magnetic fields, magnetic drug delivery carriers for controlled release, data storage media for hard disk drives and magnetic tapes, pigments in paints and coatings for rust-resistant finishes, catalysts for Fischer-Tropsch synthesis and water gas shift reactions, gas sensors for detecting flammable gases, lithium-ion battery cathodes for improved energy density, water remediation for arsenic and heavy metal removal via adsorption, ferrofluids for sealing and damping applications, and magnetic separation systems for cell sorting and protein purification. The magnetite (Fe3O4) phase provides superparamagnetic properties ideal for biomedical applications.