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PubMed · 16159276

Generating MnO2 nanoparticles using simulated amorphization and recrystallization.

Thi X T Sayle·C Richard A Catlow·R Regina Maphanga·Phuti E Ngoepe·Dean C Sayle
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Abstract

Models of MnO2 nanoparticles, with full atomistic detail, have been generated using a simulated amorphization and recrystallization strategy. In particular, a 25,000-atom "cube" of MnO2 was amorphized (tension-induced) under molecular dynamics (MD). Long-duration MD, applied to this system, results in the sudden evolution of a small crystalline region of pyrolusite-structured MnO2, which acts as a nucleating "seed" and facilitates the recrystallization of all the surrounding (amorphous) MnO2. The resulting MnO2 nanoparticle is about 8 nm in diameter, conforms to the pyrolusite structure (isostructural with rutile TiO2, comprising 1 x 1 octahedra) is heavily twinned and comprises a wealth of isolated and clustered point defects such as cation vacancies. In addition, we suggest the presence of ramsdellite (2 x 1 octahedra) intergrowths. Molecular graphical snapshots of the crystallization process are presented.

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CrystallizationCrystallography, X-RayManganese CompoundsModels, MolecularNanostructuresOxidesTime FactorsJournal ArticleResearch Support, Non-U.S. Gov't

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Thi X T Sayle, C Richard A Catlow, R Regina Maphanga, Phuti E Ngoepe, Dean C Sayle. 2005-09-21. Generating MnO2 nanoparticles using simulated amorphization and recrystallization.. https://doi.org/10.1021/ja0434073

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