Extrinsic structure changes by STM at 65 K on Si(001)

Abstract

Using variable-temperature scanning tunneling microscopy to image buckled dimers in a $C(4\ifmmode\times\else\texttimes\fi{}2)$ phase on Si(001) at 65 K under conventional scanning conditions, we have observed symmetric dimers in the $P(2\ifmmode\times\else\texttimes\fi{}1)$ phase and the flip-flop motion of dimers at the boundary of two different phases. Careful investigation shows that higher tunneling currents produce larger areas of $P(2\ifmmode\times\else\texttimes\fi{}1)$ phase and higher flip-flop rates of individual dimers. We have measured and plotted the flip-flop rate as a function of current. The origin of the phase transition and the flip-flop dimer motion are discussed.