Effect of chromium ion substitution of ZnCo ferrites on magnetic induction heating

Abstract

Magnetic nanoparticles (MNPs) with a suitable Curie temperature and high heating efficiency are desired in magnetic induction hyperthermia (MIH) with self-regulating temperature characteristics. Here, the influence of Cr 3+ substitution on the Curie temperature and heating efficiency (defined as specific absorption rate, SAR) of Zn 0.54 Co 0.46 Cr x Fe 2-x O 4 (0.45 ≤ x ≤ 0.75) nanoparticles synthesized by hydrothermal method was investigated. With the increasing Cr 3+ content, the Curie temperature decreases linearly from 102.5 °C to 28.6 °C and the SAR decreases from 54.3 W g −1 to 7.4 W g −1 . Noticeably, when x = 0.7, the MNPs have a SAR of 21.8 W g −1 and the temperature of the MNPs suspension can self-regulate at 43.8 °C, which owns the potential for self-regulating temperature MIH. To our knowledge, the SAR of 21.8 W g −1 , under an alternating magnetic field within the biological safety limit ( H · f < 5 × 10 9 A m −1 s −1 ), is the highest value for self-regulating temperature MIH. • The effect of Cr 3+ substitution on Curie temperature and SAR were studied. • The Curie temperature and SAR decrease with the Cr 3+ content (0.45 ≤ x ≤ 0.75). • The SAR of MNPs ( x = 0.7) is 21.8 W g −1 under biological safety limit magnetic field. • The MNPs suspension ( x = 0.7) can self-regulate temperature at 43.8 °C. • The MNPs have the potential for self-regulating temperature MIH.