Carbon atomic chain formation on the β-SiC(100) surface by controlled sp→sp3 transformation

We use atom-resolved scanning tunneling microscopy to evidence the formation of carbon atomic chains on the C-terminated beta-SiC(100) surface. These carbon atom lines, which exhibit an extremely high thermal stability (up to approximate to 1200 degrees C), comprise buckled single bond C-C dimers (sp(3)) having a direction perpendicular to the C=C triple bond dimers (sp) forming a c(2 x 2) surface reconstruction. Their presence does not result in/or from surface antiphase boundaries, and their density increases with annealing time. The results suggest anisotropic (tensile and compressive) surface stress as a leading driving force in this carbon sp --> sp(3) diamondlike temperature controlled transformation.