Abstract
Microstructural changes of single-crystal 4H silicon carbide (SiC) induced by nanoindentation under various conditions were investigated. It was found that nanoindentation at different crystal orientations induced different Raman spectroscopic characteristics. Cross-sectional observation by transmission electron microscopy indicated that a very deep subsurface damage region was formed where dislocations occurring along the basal planes, crystal grains rotation and micro-cracks were observed. The microstructures of the damage regions were strongly affected by the nanoindentation conditions. Coupled analysis of lattice fringes and Raman spectra indicated that a phase transformation from 4H-SiC to 3C-SiC occurred during nanoindentation, which has never been reported before. Furthermore, the 4H to 3C phase transformation strongly depended on the indenter orientation with respect to the SiC crystal. These findings are meaningful for low-damage precision machining of SiC substrates.
Original language | English |
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Article number | 265303 |
Journal | Journal of Physics D: Applied Physics |
Volume | 50 |
Issue number | 26 |
DOIs | |
Publication status | Published - 2017 Jun 12 |
Keywords
- crystal orientation
- dislocation
- nanoindentation
- phase transformation
- single-crystal silicon carbide
- subsurface damage
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Acoustics and Ultrasonics
- Surfaces, Coatings and Films