Interfacial reactions of thin titanium aluminide films with Al2O3 films and with sapphire
1993; Elsevier BV; Volume: 162; Issue: 1-2 Linguagem: Inglês
10.1016/0921-5093(90)90034-z
ISSN1873-4936
AutoresM. Nathan, Christopher R. Anderson, J. S. Ahearn,
Tópico(s)Semiconductor materials and devices
ResumoInterfacial reactions between thin (approximately 500 Å) titanium aluminide films with 30, 50 and 70 at.% aluminum, and both electron-beam evaporated Al2O3 and sapphire, were investigated with transmission electron microscopy (TEM) and X-ray photoemission spectroscopy (XPS) at 700–900 °C. Single-phase aluminides are formed by reacting thin multi-layered layered Ti/Al stacks at temperatures below 700 °C. All three aluminides react with alumina at 900 °C after 100 s. The reaction involves in-diffusion of oxygen into, and out-diffusion of aluminum from the aluminide, resulting in titanium enrichment of the aluminide and the formation of titanium oxides. The reaction is spatially limited. The observed reactivity of aluminum-rich aluminides with Al2O3 contrasts with all previously reported bulk results, and indicates that on a nanometer scale, titanium aluminides are chemically incompatible with Al2O3.
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