Skeletal range FT-IR transmission spectra of submicron commercial high purity #alpha#-Al_2O_ powders produced by different methods

摘要

Fourier transform infrared (FT-IR) transmissionspectra of six commercially available #alpha#-alumina powdersproduced by two different production methods, i.e., in-situchemical vapor deposition and hydrolysis of aluminum alkoxideare measured in the 400-1000 cm~(-1) of infrared wavenumberregion. Distinctive peaks are detected at 473, 626 and 703 cm~(-1) wavenumbers in the spectra of the powders produced by in-situ chemical vapor deposition. Scanning electron microscope(SEM) observation of the powders shows a significant shapedifference between the powders, where the powders produced byin-situ chemical vapor deposition seem to have more regular andnearer to spherical shape than the others. The differences inspectra are explained by the generalized theory of averagedielectric constant considering influence of the spherical shape ofthe powder particles on the FT-IR transmission spectra.