Formation of a new aluminum oxide with the composition AlO2 by interfacial reaction between Pt and α-Al2O3
1994; Elsevier BV; Volume: 42; Issue: 4 Linguagem: Inglês
10.1016/0956-7151(94)90129-5
ISSN1873-2879
AutoresY. Charles Lu, R. Dieckmann, S.L. Sass,
Tópico(s)Semiconductor materials and devices
ResumoA new aluminum oxide, with the nominal composition AlO2, very likely in aluminum peroxide oxide, was formed at the interface between Pt and α-Al2O3 diffusion-bonded in a reducing atmosphere at 1200°C. The structure, chemistry and kinetics of formation of AlO2 were characterized by X-ray fluorescence microanalysis, Rutherford backscattering spectrometry, forward recoil spectroscopy, X-ray diffraction, electron spin resonance, electron energy loss spectroscopy, X-ray photoelectron spectroscopy, optical microscopy, scanning electron microscopy, transmission electron microscopy and electron diffraction. Near bulk quantities of AlO2 were obtained for long bonding times; a 13 μm thick interlayer after 96 h at 1200°C. The thickness of the interlayer increased linearly with time indicating that the kinetics of the reaction are interface controlled. Based on electron diffraction and powder X-ray diffraction observations the structure of AlO2 was shown to be orthorhombic. It is suggested that a metastable oxide can form in direct contact with α-Al2O3 under a special set of conditions where the dissolution of Al into Pt provides a sufficient decrease in free energy to allow the oxidation of α-Al2O3, with very slow transport of oxygen away from the reaction front along the Pt-Al2O3 interface.
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