Effect of Cu doping on the static dielectric constant of nanocrystalline ZnO

Abstract

Cu-doped ZnO nanoparticles were synthesized by a simple rheological phase reaction–precursors method using zinc acetate, cupric acetate and oxalic acid for different atomic percentages of Cu doping. X-ray diffraction studies confirmed the correct phase formation and compositions were obtained by energy dispersive X-ray analysis. Particle sizes were recorded from small angle X-ray scattering studies. The static dielectric constant, calculated from the shift in band-gap energy, showed a gradual decrease with Cu doping. A simple theoretical calculation, based on the Penn model, was performed to explain the observed change in dielectric constant with doping. The model could successfully describe the dependence of the static dielectric constant of nanocrystalline ZnO on doping concentration.

Keywords:

• zinc oxide
• nanocrystalline
• dielectric constant
• modelling

Acknowledgements

One of us wishes to thank the Council for Scientific and Industrial Research (CSIR), Government of India, for the award of a Junior Research Fellowship (JRF) during this study. We acknowledge the financial assistance of Department of Science & Technology (DST), Government of India and the University Grants Commission (UGC) under the ‘University with potential for excellence’ scheme.