First principles analysis of impurities in silicon carbide grain boundaries

Theoretical Studies of the Atomic and Electronic Structures of Grain Boundaries in Silicon and Silicon-carbide

The atomic and electronic structures of a facetted twin boundary in Si and a twin boundary in 6-Sic have been studied theoretically for the first time. The atomic structure of the {211}/{111} facets in Si based on the model by Bourret and Bacmann has been optimised by the Keating model, and the electronic structure has been calculated using a supercell technique and a tight-binding model. It ha...

Titanium Impurities in Silicon, Diamond, and Silicon Carbide

Since transition metal impurities affect the electronic and optical properties of semiconductors [1], it is important to understand the role of such unavoidable impurities on those properties. At the same time, transition metals in semiconductors can be used in other unusual situations. The energy levels related to transition metal impurities are aligned with respect to each other for the same ...

Segregation of Interstitial Impurities at Grain Boundaries in Transition Metals

Grain boundary resistance to amorphization of nanocrystalline silicon carbide

Under the C displacement condition, we have used molecular dynamics simulation to examine the effects of grain boundaries (GBs) on the amorphization of nanocrystalline silicon carbide (nc-SiC) by point defect accumulation. The results show that the interstitials are preferentially absorbed and accumulated at GBs that provide the sinks for defect annihilation at low doses, but also driving force...

Impact damage on silicon carbide : first results

This paper deals with the damage of ceramic materials after impact. The main information on the phenomenology and the kinetic damage are often localized inside the Hertzian cone crack area [I]. With a ceramic tile target, it is not possible to obtain any information during the test. Therefore a new geometry of ceramic target, called "Match was developed in order to put crack gauge inside the He...