Specific signatures of α-alumina powders prepared by calcination of boehmite or gibbsite
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Date
2010-04-09
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Abstract
The specific signatures of α-Al2O3 powders by a combination of X-ray diffraction (Rietveld analysis), scanning
electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thermal analysis (TG–DTA) and
cathodoluminescence (CL) were investigated. Thus, α-alumina was prepared by calcination of boehmite or
gibbsite at 1573 K for 24 h. The size of α-alumina crystallites obtained using boehmite precursor was smaller
than that obtained using gibbsite precursor. The difference in oxygen vacancies (F+-centers) amount between
α-Al2O3 powder obtained by calcination of gibbsite and boehmite was confirmed by CL spectra. Furthermore,
the Ti3+ emission at 1.71 eV is absent in α-Al2O3 powder obtained by calcination of gibbsite. CL has been
demonstrated as a possible method for differentiation between the various α-alumina powders.