Al-doped Zinc Oxide nanocrystalline powders prepared by mechanical milling

SERGIO FERRARI; LAURA CRISTINA DAMONTE

La Plata

Conferencia; HK 2010 - Humboldt Kolleg International Conference on Physics ?Argentina-Alemania: un siglo de cooperación científica en Física.?; 2011

Alexander von Humboldt-Foundation

The interest in new materials of nano-sized scale for applications in industry, medicine and other fields has led to research in the many ways of producing them with good efficiency and trying to improve the quality of the final products. Of the many techniques of obtaining nanomaterials, mechanical ball-milling has the virtues of being efficient in producing large amount of material, obtaining incorporation of doping material into the main structure and/or creating blends, alloys, non-equilibrium phases and oxide-reduction reactions, etc. This is of particular importance in the study of semiconductors, like ZnO, whose electrical/optic/other properties can be ameliorated with doping of metals or metal-oxide substances. The aim of this article is to study the final products of milling ZnO powders doped in different proportions (5, 10 and 30 at%) with Al powder. We have used X-ray diffraction (XRD) for following the structural ZnO changes, and we have use Positron Annihitalion Lifetime Spectroscopy (PALS) to keep on eye on defect creation with milling. We have observed that under certain circumstances ZnO can be reduced in milling with Al without obtaining alumina. XRD patterns corroborate the incorporation of aluminum into the wurtzite ZnO structure.   Ternary oxides of the form Zn1-xAlxO are obtained in all samples subjected to 16 hours of milling time.