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Journal of Nanomaterials
Volume 2012, Article ID 439010, 4 pages
Research Article

Quantum Size Effect in ZnO Nanoparticles via Mechanical Milling

Advanced Materials Research Laboratory, Department of Mechanical Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia

Received 7 July 2011; Revised 15 September 2011; Accepted 16 September 2011

Academic Editor: William W. Yu

Copyright © 2012 Nurul Azri Khalisah Aznan and Mohd Rafie Johan. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


ZnO nanocrystals were successfully produced by mechanical milling. It is shown that mechanical milling is very effective and simple to produce ZnO nanoparticles with the possibility of obtaining large quantities of materials. Size effects in ZnO nanoparticles were probed by XRD and UV-vis and photoluminescence (PL) spectroscopy. Absorption due to free electron was clearly observed, whereas strong PL lines were recorded in the UV and blue region. The absorbance and photoluminescence were found to increase with reduction in particle size. Blueshift of excitonic and emission peaks was observed as a consequence of the size quantization effect. Formation of pure ZnO phase was confirmed from XRD pattern and the optical spectroscopy.