Abstract
Single crystal Al2O3 (sapphire) is noted for its extreme resistance to attack by most chemical reagents. The reactivity of amorphous Al2O3 has not been reported although it is well known that an amorphous layer can be produced by ion beam irradiation at 77 K or by implantation of certain chemical species at 300 K. In the current study, an amorphous layer was produced by ion beam mixing of Zr/Al2O3 using Kr at 300 K or by implantation with Cr, Zr, Sn or Al plus O at 77 K. The amorphous layer can be completely removed by etching in an acid solution of HNO3-HF-H2O. The attack ceases once the amorphous region is dissolved. Crystalline samples containing the same implanted species are not attacked. The amorphous state is necessary for this enhanced chemical reactivity and the results for the stoichiometric implant of Al + O indicate that it is sufficient. The implanted (impurity) species may influence the rate of dissolution.
| Original language | English |
|---|---|
| Pages (from-to) | 596-598 |
| Number of pages | 3 |
| Journal | Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms |
| Volume | 127-128 |
| DOIs | |
| State | Published - May 1997 |
| Externally published | Yes |
Funding
Researchs upportedin part by the AssistantS ecretary for Energy Efficiency and RenewableE nergy,Office of TransportatioTne chnologiesa, s parto f theH igh Temperature MaterialsL aboratoryU ser Programa nd by the Division of MaterialsS ciencesU, S, Departmenotf Energy,a t Oak Ridge National Laboratory,m anagedb y Lockheed Martin EnergyR esearchC orporationfo r the U.S. Department of Energy under contract number DE-ACOS-96OR22464a, nd by the Centerf or MaterialsP rocessing, Universityo f Tennessee.