Etude du polytypisme des cristaux de carbure de silicium par diffraction électronique par réflexion

Some polytypes of silicon carbide are studied by means of reflexion electron diffraction (RHEED). This simple method allows a wide investigation over the whole surface of large crystals. Reciprocal lattice planes of well known basic polytypes and of intermediate regions between them are recorded. `Forbidden' extra spots characterizing the polytypic structure appear from multiple interactions. Examples of localized long-period or disordered polytypes are shown. A new 441R polytype has been found.