A systematic study of cobalt-zinc ferrite nanoparticles for self-regulated magnetic hyperthermia.

Cobalt-zinc ferrite nanoparticles having composition Co 1-x Zn x Fe 2 O 4 were processed by sol-gel method with particle sizes ranging from 10.8 nm to 3.6 nm. The crystal structure, particle size, and magnetic properties were investigated by XRD, FTIR, TEM, and VSM techniques. Single domain nature was established from the coercivity versus particle size curve. The dependence of specific saturation magnetization with zinc concentration was discussed in terms of site occupancy of cations and supported by FTIR measurements. A few single domain nanoparticle compositions exhibiting low Curie temperatures and reasonably good magnetization were subjected to induction heating measurement to explore the possibility of using the materials for magnetic hyperthermia. The material, having the composition, Co 0.37 Zn 0.63 Fe 2 O 4 was shown to be an excellent candidate for conducting hyperthermia study with self-regulated temperature at 46 °C. • Nanoparticles of size from 3.6 nm to 10.8 nm were synthesized by sol-gel method. • The chelating agent, polyvinyl alcohol was found to be powerful in controlling the particle size. • The transition from multi-domain to single domain nanoparticle was established with zinc concentration. • The composition Co 0.37 Zn 0.63 Fe 2 O 4 was developed with Curie temperature, 46 °C. • Self regulated magnetic hyperthermia in the composition, Co 0.37 Zn 0.63 Fe 2 O 4 was achieved. [ABSTRACT FROM AUTHOR]