STM study of CeTe$_{3}$: contribution of the subsurface lattice

We have studied the nature of the surface charge distribution in CeTe$_{3}$ with scanning tunneling microscopy (STM). At 77 K, the STM topography and Fourier transform show both the atomic lattice of surface Te atoms arranged in a square net and the CDW modulations oriented at 45 degrees with respect to the Te net. In addition, we observe peaks in the Fourier transform that we attribute to atoms lying below the surface Te net. We discuss the possibility of both subsurface Ce and Te as giving rise to this signal; density functional theory calculations indicate that the subsurface Ce atom gives a more significant contribution to the overall tunneling current.