MOSSBAUER-SPECTROSCOPY ON BENT SI CRYSTALS

We have shown through Mossbauer spectroscopy that the electric field g radient (EFG), associated with an atomic defect, is sensitive to the b ending of ultrathin Si crystals. The changes in the EFG depend on the bending direction. A direct application is the derivation of the orien tation of defects that are located in the crystal's surface region. We have used this observation for determining the configuration of Co di mers in Si. Based on the bending experiments, the pair axis is found t o point in the [110] direction with respect to the host lattice.