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New and Unforeseen Crystal Growth Processes for a Metal Oxide.

ABSTRACT: The synthesis of corundum (α-Al₂O₃) via a layered Al₂O₃-MoO₃ system was directly observed for the first time. This revealed a new crystal growth process with three key features: (1) the formation of an Al₂(MoO₄)₃ intermediate layer through a solid-solid interaction in the temperature range of ∼705-860 °C; (2) the melting of the Al₂(MoO₄)₃ layer between approximately 870 and 890 °C; and (3) the decomposition of Al₂(MoO₄)₃ to corundum between 950 and 1100 °C. This molten intermediate decomposition (MIND) mechanism produced corundum, which was light bluish-gray in color and was defined in CIE (L* a* b*) color space as L* = 76.65, a* = -1.09, and b* = -6.20. The reagents used in this study were the same as those used in MoO₃ flux growth studies on the synthesis of corundum, therefore demonstrating that the previous work only gave a superficial treatment of the mechanism of formation.

SUBMITTER: Whitehurst ME

PROVIDER: S-EPMC10753548 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature

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New and Unforeseen Crystal Growth Processes for a Metal Oxide.

Whitehurst Michaela E ME Hall Simon R SR

ACS omega 20231212 51

The synthesis of corundum (α-Al2O3) via a layered Al2O3-MoO3 system was directly observed for the first time. This revealed a new crystal growth process with three key features: (1) the formation of an Al2(MoO4)3 intermediate layer through a solid-solid interaction in the temperature range of ∼705-860 °C; (2) the melting of the Al2(MoO4)3 layer between approximately 870 and 89 ...[more]

PMID: 38162768

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