Synthesis and magnetic properties of gadolinium substituted zinc ferrites

Gadolinium-doped zinc ferrite nanoparticles were synthesized using standard co-precipitation method. The samples were annealed at 1200°C to form crystalline composites. Gadolinium concentration in the precursor solution was varied from 10% to 40% with respect to iron concentration. The particles were observed to have an average particle size of 100nm by scanning electron microscope. X-ray diffraction analysis revealed significant change in the crystal structure from the cubic spinel to orthorhombic by changing gadolinium concentration from 10% to 40%. Formation of mixed phases of orthorhombic and cubic spinel gadolinium zinc iron oxides was observed. The ferromagnetic properties of the samples decreased with increasing gadolinium doping resulting in antiferromagnetic nature at 40% gadolinium concentration. Magnetic hyperthermia studies confirmed a high heating rate for samples with 20% and 30% gadolinium doping which suggest their use in cancer therapy. •Gadolinium doped zinc ferrite specific absorption rate was optimized.•Antiferromagnetic property was observed at 40% gadolinium doping•The specific absorption rate for 40% doping was low (3.816W/g)•The particle is desirable for contrasting agent in cancer therapy.