Structural and dielectric properties of NiO nanoparticles

► NiO nanoparticles were prepared at low temperature (70 °C) by wet chemical precipitation method. ► Stoichiometry of the NiO nanoparticles was controlled by hydrogen peroxide H2O2. ► Dielectric properties were optimized by controlling the composition of NiO nanoparticles. ► Large dielectric constants 35 and 40 for NiO particles were achieved.