Investigating the Trimethylaluminium/Water ALD Process on Mesoporous Silica by In Situ Gravimetric Monitoring
AbstractA low amount of AlOx was successfully deposited on an unordered, mesoporous SiO2 powder using 1–3 ALD (Atomic Layer Deposition) cycles of trimethylaluminium and water. The process was realized in a self-built ALD setup featuring a microbalanceand a fixed particle bed. The reactor temperature was varied between 75, 120, and 200 °C. The self-limiting nature of the deposition was verified by in situ gravimetric monitoring for all temperatures. The coated material was further analyzed by nitrogen sorption, inductively coupled plasma-optical emission spectroscopy, powder X-ray diffraction, high-resolution transmission electron microscopy, attenuated total reflection Fourier transformed infrared spectroscopy, and elemental analysis. The obtained mass gains correspond to average growth between 0.81–1.10 Å/cycle depending on substrate temperature. In addition, the different mass gains during the half-cycles in combination with the analyzed aluminum content after one, two, and three cycles indicate a change in the preferred surface reaction of the trimethylaluminium molecule from a predominately two-ligand exchange with hydroxyl groups to more single-ligand exchange with increasing cycle number. Nitrogen sorption isotherms demonstrate (1) homogeneously coated mesopores, (2) a decrease in surface area, and (3) a reduction of the pore size. The experiment is successfully repeated in a scale-up using a ten times higher substrate batch size. View Full-Text
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Strempel, V.E.; Knemeyer, K.; Naumann d’Alnoncourt, R.; Driess, M.; Rosowski, F. Investigating the Trimethylaluminium/Water ALD Process on Mesoporous Silica by In Situ Gravimetric Monitoring. Nanomaterials 2018, 8, 365.
Strempel VE, Knemeyer K, Naumann d’Alnoncourt R, Driess M, Rosowski F. Investigating the Trimethylaluminium/Water ALD Process on Mesoporous Silica by In Situ Gravimetric Monitoring. Nanomaterials. 2018; 8(6):365.Chicago/Turabian Style
Strempel, Verena E.; Knemeyer, Kristian; Naumann d’Alnoncourt, Raoul; Driess, Matthias; Rosowski, Frank. 2018. "Investigating the Trimethylaluminium/Water ALD Process on Mesoporous Silica by In Situ Gravimetric Monitoring." Nanomaterials 8, no. 6: 365.
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