Influence of annealing on magnetic induction heating efficiency of Zn–Co–Cr ferrite nanoparticles

Abstract

The Curie temperature and heating efficiency of magnetic nanoparticles (MNPs) are two important parameters for the application in self-regulating temperature magnetic induction hyperthermia. Here we studied the effect of annealing on the Curie temperature and heating efficiency of the Zn 0.54 Co 0.45 Cr 0.6 Fe 1.4 O 4 nanoparticles prepared by hydrothermal method. The results suggest that the annealing reduces the Curie temperature of the MNPs from 61 to 51.5 °C. The heating efficiency of the MNPs has been more than doubled after annealing, i.e., from 4.4 to 9.3 W/g. The decrease of Curie temperature and increase of heating efficiency are beneficial for the application of MNPs in self-regulating temperature magnetic induction hyperthermia.

The heating efficiency of magnetic nanoparticles under an alternating magnetic field

“…This is because that the C/ZCF-3 have a lower Curie temperature ( Tc, as seen Fig. 6 a, b), which can be ascribed to the migration of Co 2+ ions from B sites to A sites 35 . Since the super-exchange interaction between Co 2+ in A sites and Fe 3+ in B sites is weaker than that between Fe 3+ in both A sites and B sites, the Co 2+ migration from B sites to A sites will cause the decrease of the super-exchange interaction, leading to the decrease of Tc 36 .…”

The Curie temperature: a key playmaker in self-regulated temperature hyperthermia

“…210 The SLP of the adjusted Zn 0.54 Co 0.46 Cr 0.6 Fe 1.4 O 4 MNPs with T C of 48.8 °C was about 6.53 W g −1 under the same applied AMF. 210 To further check that the SLP will be enhanced by increasing the heat fraction arising from relaxation loss, Yu et al 211 synthesized Zn 0.54 Co 0.46 Cr 0.6 Fe 1.4 O 4 MNPs with a T C of 61 °C and SLP of 4.4 W g −1 , and after annealing, the T C decreased from 61 °C to 51.5 °C and the SLP increased from 4.4 W g −1 to 9.3 W g −1 .…”