Au-induced deep groove nanowire structure on the Ge(001) surface: DFT calculations

A giant Ge zigzag chain reconstruction with a quadruple step height consisting of a top layer Ge zigzag nanowire and two {111} nano-sidefacet Au trimers, which displays c(8 × 2) zigzag nanowire structure STM images above a critical temperature, 573 K in the experiment. The top layer Ge and Au atomic disorder introduces the chevron units into the zigzag nanowire structure STM image. The long range c(8 × 2) ordering transformed into a local c(8 × 2) symmetry with decreasing temperature is associated with the second-order phase transition as per the experimental observations.186