Photoacoustic infrared spectroscopy of nanoclusters Al 2 O 3 </mml:…
1993; American Physical Society; Volume: 48; Issue: 3 Linguagem: Inglês
10.1103/physrevb.48.1830
ISSN1095-3795
AutoresJackie Y. Ying, Jay B. Benziger, H. Gleiter,
Tópico(s)Quantum Dots Synthesis And Properties
ResumoStoichiometric nanometer-sized ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ clusters were generated by direct rf magnetron sputtering from an \ensuremath{\alpha}-${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ target in an inert atmosphere. Nanostructured compacts were derived by compacting the clusters in situ under ultrahigh vacuum. Photoacoustic infrared spectroscopy was applied in the vibrational study of the ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ nanoclusters and nanostructured compacts. The two samples were associated with considerable spectral broadening of the phonon band, compared to conventional \ensuremath{\alpha}- and \ensuremath{\gamma}-${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ polycrystals. These were attributed to the finite-crystal effects of the nanometer-sized grains and to the disorder in the grain boundaries which made up a significant volume fraction of the samples, particularly in the nanostructured compacts.
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