Magnetic Properties, Heat Generation, and Apatite Formation Ability of Mg-Ti Ferrite Particles Synthesized by Solid-State Reaction and Polymerized Complex Methods

Titanium-doped ferrite has garnered significant interest as thermoseeds for cancer hyperthermia because of its controllable Curie point near body temperature, which prevents overheating and ensures high biological safety. However, few studies examine the effect of the synthesis conditions on microstructure, magnetic properties, and heat generation in an alternating magnetic field. Herein, Mg_1+xFe_2−2xTi_xO₄ (x = 0.35, 0.45) particles are synthesized by a solid-state reaction and polymerized complex methods, followed by sintering at various temperatures. Their magnetic properties and heat generation behavior in an alternating magnetic field are investigated. Particles with x = 0.45 generate significantly less heat than those with x = 0.35, despite both being single-phase ferrite. Particles synthesized by the polymerized complex method at a sintering temperature of 1200 °C exhibit lower saturation magnetization but higher temperature increases compared with the solid-state reaction method. Additionally, in the sintering temperature range of 800–1000 °C, a temperature increase of more than 10 °C is observed in the polymerized complex method, likely a result of the inclusion of highly crystalline superparamagnetic particles. Furthermore, the ferrite particles form bone-like apatite on their surface in simulated body fluid, suggesting their potential as a novel material combining hyperthermia and bone integration properties.