We have fabricated an $H-$phase ${\mathrm{TaS}}_2$ crystal in the surface layer of a $T-$phase ${\mathrm{TaS}}_2$ single crystal using a scanning tunneling microscope (STM) tip. After applying a relatively high bias voltage to the STM tip, we observed a significant change of the surface indicating the formation of the $H$ phase near the exposed region. The STM image shows the characteristic triangular phase boundary between the original $T$ phase $(\sqrt{13}\times \sqrt{13}$ charge-density-wave superstructure) and the newly fabricated $H$ phase (a triangular atomic lattice). Around the phase boundary, the local distortions of the $\sqrt{13}\times \sqrt{13}$ charge-density-wave superstructure have also been observed. The high-resolution STM image near the phase boundary suggests a sliding of the surface $S$ atomic sheet by the STM modification procedure.

• Received 30 June 1997

DOI:https://doi.org/10.1103/PhysRevB.56.R15573