Effect of hydrogen annealing on structure and dielectric properties of zinc oxide nanoparticles

In this article, Zinc Oxide (ZnO) samples were synthesized by Co-precipitation method. The influence of hydrogen annealing on the structure and dielectric behavior of zinc oxide nanoparticles was investigated. X-ray diffraction measurements indicate that all the particles possess a typical wurtzite structure without any other impurity phases. The structure and size of these nanoparticles are not influenced by hydrogen annealing but a small change in the peak position and intensity was observed. The low-temperature dielectric study of the samples was studied in the frequency range 20 Hz to 1 MHz between 80 K and 300 K and these measurements show that the ZnO nanoparticles further annealed at hydrogen atmosphere exhibit a high dielectric permittivity and a large increase in ac conductivity compared to that of the corresponding ZnO nanoparticle annealed in air. The hydrogen occupancy of oxygen atoms to play an important role in enhancing dielectric permittivity and conductivity in ZnO nanoparticles.