Title | Structural and thermal characterisation of nanostructured alumina templates |
Publication Type | Journal Article |
Year of Publication | 2006 |
Authors | Brown, I.W.M., Bowden M.E., Kemmitt T., and Mackenzie K.J.D. |
Journal | Current Applied Physics |
Volume | 6 |
Issue | 3 |
Pagination | 557 - 561 |
Date Published | 2006 |
ISSN | 15671739 (ISSN) |
Keywords | Alumina, Anodic alumina, Aspect ratio, Membrane fabrication, Nanostructured materials, nuclear magnetic resonance spectroscopy, Reaction sequence, Thermoanalysis, Thermodynamic properties, X ray diffraction, XRD |
Abstract | Nanostructured anodic aluminium oxide materials containing a two dimensional array of high aspect ratio aligned pores of 200 nm diameter have been heat treated in air at temperatures up to 1340 °C. Thermal analysis shows two discrete irreversible exothermic events at 850 °C and 1020 °C. XRD and 27Al MAS NMR show the progressive development of local and long range order in the heated structures and indicate a reaction sequence of amorphous Al2O3 → θ-Al2O3 → α-Al2O3 (corundum). NMR shows the co-existence of aluminium in 4, 5 and 6-coordinated sites through most of the heating sequence until the stable (6-coordinated) corundum phase is established. Phosphorus impurities incorporated during the membrane fabrication process crystallise as an AlPO4 phase above 850 °C and play an important role in directing the chemical, physical and structural outcomes of the heat treatment. © 2005 Elsevier B.V. All rights reserved. |
URL | http://www.scopus.com/inward/record.url?eid=2-s2.0-33744546523&partnerID=40&md5=529113aa1b7487b9af1fae6f330080d4 |
DOI | 10.1016/j.cap.2005.11.060 |