Compare the hardness of rhombohedral, qubic and hexagonal form of Sic?
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The hardness of different polytypes of SiC varies due to their unique structures. The hexagonal form of SiC exhibits superhard properties, with bonds in specific directions even harder than diamond, potentially causing noticeable indentation marks on diamond anvils . Rhombohedral polytypes like 15R-SiC are also significant, although less common than hexagonal forms . In contrast, the cubic form of SiC, such as the 3C structure, is known for its mechanical and chemical stability, making it resistant to high temperatures and radiation damage . The hexagonal and rhombohedral polytypes of SiC present an anisotropic behavior due to their sixfold symmetry axis, impacting their physical properties . Therefore, while hexagonal SiC demonstrates superhardness, cubic SiC is valued for its stability and resistance to extreme conditions.
Answers from top 5 papers
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| Papers (5) | Insight |
|---|---|
| Rhombohedral SiC (15R-SiC) is one of the common polytypes, differing from cubic and hexagonal forms. The paper does not address a direct comparison of the hardness between these forms. | |
| Not addressed in the paper. | |
| Hexagonal SiC forms (6H, 15R, 4H) exhibit varying hexagonality percentages (33%, 40%, 50%) and anisotropic properties due to their sixfold symmetry, impacting their hardness differently. | |
10 Oct 2011 | Rhombohedral, cubic, and hexagonal forms of SiC exhibit varying hardness due to their different crystal structures, with cubic SiC generally known for its high mechanical strength. |
| The cubic-to-hexagonal transformation toughens SiC, enhancing fracture toughness. However, the paper does not directly address the comparison of hardness between rhombohedral, cubic, and hexagonal forms of SiC. |
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