Effects of Ni co-doping concentrations on dielectric and magnetic properties of (Co, Ni) co-doped SnO₂ nanoparticles

In this work, the dielectric and magnetic properties of (Co, Ni) co-doped SnO₂ nanoparticles were studied using ac impedance spectroscopy and magnetic properties measurement system or quantum design superconducting quantum interference device. Results showed that dielectric constant (ε _r ), dielectric loss (ε″), and ac electrical conductivity (σ _AC ) are strongly frequency dependent. A decrease in frequency was accompanied with an increase in ε _r and ε″ values, whereas, a decrease in the dielectric constant was observed with the increase of Ni co-doping concentration. It was found that the dielectric constant and dielectric loss values decrease, whilst AC electrical conductivity increases with increase in co-doping concentration. Magnetization measurements revealed that the Ni co-doped SnO₂ samples exhibits room temperature ferromagnetism. The results illustrate that (Co, Ni) co-doped SnO₂ nanoparticles have an excellent dielectric, magnetic properties, and high electrical conductivity than those of co-doped samples reported previously, indicating that these (Co, Ni) co-doped SnO₂ materials can be suitable for the purpose of high frequency device and spintronic applications.