Aging Impact on Crystal Structure and Magnetic Parameters of KFeO2 Nanoparticles

Alkaline metal ferrite nanoparticles, in particular KFeO2, are considered as good mediators of magnetic hyperthermia treatment since they have a relatively high saturation magnetization and are biocompatible. Here, we study the aging effects in KFeO2 nanoparticles and reveal the aging impact on their structural and magnetic characteristics, performing a detailed X-ray diffraction study and vibrating sample magnetometry at temperatures ranging from 300 to 500 K. Crystal structure of nanoparticles undergoes essential changes, including an increase of lattice parameter. Saturation magnetization becomes higher and Curie temperature tends to increase for the aged nanoparticles, but those characteristics remain almost unchangeable at magnetic hyperthermia-relevant temperatures (up to 315–320 K). We evaluated the heating capability of the aged and as-prepared KFeO
2
nanoparticles by varying the magnetic field strength and applied AC current frequency using COMSOL Multiphysics® software. The results of multiphysics simulation have revealed that the heating efficiency of as-prepared and aged KFeO
2
nanoparticles is temperature independent and keeps a high magnitude, proving the wide perspectives in the use of the nanoparticles under study in biomedical applications.