How plastic deformation can produce texture in graphitic films of boron nitride, carbon nitride, and carbon

Abstract

The graphitic forms of carbon, boron nitride, and carbon nitride grown in energetic film-deposition processes or processed using ion irradiation often possess an in-plane c-axis texture. In this texture the basal planes of the graphitic material are perpendicular to the substrate. We show that the in-plane c-axis texture can be produced through plastic deformation as a mechanism to relieve the large ion-induced compressive stresses in these materials. Specifically, basal-plane slip and kinking processes would produce a rotation of the c-axis towards the plane of biaxial compressive stress. Once the c-axis has rotated to lie in the plane of the substrate, further deformation by basal-plane slip cannot occur. Then, in the absence of additional stress-reduction pathways, the stress level will rise if the material undergoes further compressive elastic strain. The possible relationship between this stress build-up and nucleation of high-density phases, such as cubic boron nitride, is briefly discussed.