Nanoarchitectonics of PEG-Coated Ni-Zn Ferrite Nanoparticles and Mechanical Analysis of Heat Generation by Magnetic Relaxation

The magnetic relaxation of nanoparticles (MNPs) has been used as a potential heating agent for hyperthermia treatment (MHT). This requires an understanding the mechanism MNPs, such Néel relaxation; however, few studies about using low-frequency AC field have reported. study attempts to clarify correlation between dominance in fields and properties. Nanoparticles Ni0.8Zn0.2Fe2O4 coated with poly(ethylene glycol) (PEG) were synthesized various sizes (d = 12, 15, 19 nm), subjected structural analysis, PEG modification, measurements. PEG400 coating results hydrodynamic diameter ten times smaller than that our previous sample. heat generation experiment was conducted on samples suspended solvents different viscosities presence (h 3.2 kAm−1, f 90 kHz). specific absorption rate (SAR) function viscosity 15-nm NP sample is consistent theoretically calculated value cases where dominant. Therefore, we conclude dominates 15 nm Rather being fully superparamagnetic, this partly superparamagnetic slightly ferromagnetic, certain degree affected by spin blocking. Detailed analysis crucial improve efficiency MNPs MHT.