Structural, optical and magnetic properties of Co doped CuO nano-particles by sol-gel auto combustion technique

Co-doped CuO nanoparticles were successfully prepared by sol-gel auto combustion technique to investigate structural, optical and magnetic properties. The X-ray diffraction (XRD) analysis studied the structural properties of the nanoparticles and confirms structure of the monoclinic CuO crystal structure. As the Co doping increases the volume of unit cell decrease in Co doped CuO nanoparticles. The mean crystalline size was determined using Scherrer's formula and found in the range of 35–40 nm. The effects of Co doping on the variation of the microstrucutre property in the Co doped CuO nanoparticles were revealed by scanning electron microscope (SEM). The EDX analysis showed that the atomic percentage of Cu decreases with the increasing doping (Co) concentrations, which have confirms that the Cu atoms have successfully replaced their Co counterparts as content. The optical data revealed that with an increase in Co doping level there is an energy band gap increase. The magnetic hysteresis loops of the samples indicated that the samples are super-paramagnetic in nature. The super-paramagnetic behavior of the samples is also discussed. Average crystalline size versus strain of pure and Co doped CuO nanoparticles. [Display omitted] •Cu1-xCoxO nanoparticles were synthesized by co-precipitation technique.•Single monoclinic crystal structure was confirmed.•The lattice parameters and volume decreases with increasing Co content.•The crystalline size decreased, whereas strain increased with increasing Co doping.•Cu1-xCoxO can be used in spintronics device as the nanoparticles have super-paramagnetic behavior at room temperature.