Effect of Ti Atoms on Néel Relaxation Mechanism at Magnetic Heating Performance of Iron Oxide Nanoparticles

The study was based on understanding the relationship between titanium (Ti) doping amount and magnetic heating performance of magnetite (Fe3O4). Superparamagnetic nanosized Ti-doped magnetite ((Fe1−x,Tix)3O4; x = 0.02, 0.03 and 0.05) particles were synthesized by sol-gel technique. In addition to (Fe1−x,Tix)3O4 nanoparticles, SiO2 coated (Fe1−x,Tix)3O4 nanoparticles were produced as core-shell structures to understand the effects of silica coating on the magnetic properties of nanoparticles. Moreover, the magnetic properties were associated with the Néel relaxation mechanism due to the magnetic heating ability of single-domain state nanoparticles. In terms of results, it was observed that the induced RF magnetic field for SiO2 coated (Fe0.97,Ti0.03)3O4 nanoparticles caused an increase in temperature difference (ΔT), which reached up to 22 °C in 10 min. The ΔT values of SiO2 coated (Fe0.97,Ti0.03)3O4 nanoparticles were very close to the values of uncoated Fe3O4 nanoparticles.