Magnetic and structural properties of RE doped Co-ferrite (REåNd, Eu, and Gd) nano-particles synthesized by co-precipitation

• Magnetic and structural studies of RE3+–Co-ferrite (RE=Nd, Gd, and Eu) are investigated.
• Simple co-precipitation method involving less energy and low-cost is used.
• Nanoparticles with high coercivity, magnetization and loop area are obtained.
• The obtained particles are used in nanomedicine applications like hyperthermia.

Cobalt ferrite nano-particles, Co0.9RE0.1Fe2O4, with three different rare earth ions (Nd, Eu, and Gd) were prepared by the chemical co-precipitation method. X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), Fourier Transform Infrared (FTIR), and Vibrating Sample Magnetometry were carried out to study the structural and magnetic properties, respectively. The XRD results revealed that the crystal size is about 22 nm for Gd–Co ferrite, which is close to the particle sizes observed from TEM images (20 nm). The FTIR measurements between 350 and 4000 cm−1 confirmed the intrinsic cation vibrations of the spinel structure. The results showed that the RE ions increase both vibrational frequencies and bond strength. The magnetic results showed that the highest magnetic coercivity and the loop area correspond to the Gd–Co ferrite, making it suitable for hyperthermia treatment. Also, the Curie point was decreased by the RE ions and had its lowest value for Nd–Co ferrite (336 °C).