Effect of the Vacuum-Arc Synthesis Parameters on the Structure and Magnetic Properties of NiO Nanoparticles

NiO nanoparticles are synthesized by vacuum arc sputtering. The effect of the synthesis parameters on the structural and magnetic properties of samples is studied. X-ray diffraction analysis confirms a polycrystalline structure of the nanoparticles prepared under all deposition conditions; however, the preferred orientation of crystallites depends on the deposition conditions. The magnetic behavior correlates with the crystallite size of NiO nanoparticles. Condensates with a particle size of 4–6 nm demonstrate superparamagnetic behavior, which changes into antiferromagnetic as the particle size increases.