Interrogation of $Co_xZn_yNi_z Fe_2O_4$ ferrite nanoparticles for insight into specific power loss for medical hyperthermia

Magnetic nanoparticles (MNPs) have shown to be viable candidates as heat sources for magnetic hyperthermia under an alternating magnetic field. The present work investigates heating characteristics of sol-gel processed ferro-magnetic $Co_xZn_yNi_zFe_2O_4$ (ferrite) nanoparticles with different magnetic properties. The nanoparticles were irradiated by a radio-frequency magnetic field through a 5-turns coil using a 1.2 kW heating system with variable frequency in the 295-315 kHz range and a maximum current output of 100 A. Higher specific power losses were measured for nanoparticles that had lower coercivities. The advantage of having a high specific power loss for clinical applications is that a minute amount of nanoparticle has to be introduced in the body to adequately destroy malignant tumor cells.\\[4pt] \begin{tabular}{|c|c|c|c|c|c|} \hline {Name} & {Grain Size} & {M$_r$} & {M$_s$} & {H$_c$} & {SPL$_{100A}$}\\ &(nm) & (emu/g) & (emu/g) & (Oe) & (W/g$^2$)\\ \hline Ni$_{0.5}$Zn$_{0.5}$Fe$_2$O$_4$ & 48.7 & 2.85 & 47.5 & 42.2 & 84 $\pm$ 2\\ Co$_{0.4}$Ni$_{0.4}$Zn$_{0.2}$Fe$_2$O$_4$ & 46 & 3.29 & 26.2 & 75.3 & 28 $\pm$ 3\\ NiFe$_2$O$_4$ & 42.9 & 3.47 & 14.8 & 146 & 17.0 $\pm$ 0.5\\ CoFe$_2$O$_4$ & 34.5 & 7.01 & 22.2 & 626 & 0.64 $\pm$ 0.05\\\hline \end{tabular}