Electronic states and surface structure of PdTe2 as probed by scanning tunneling microscopy and photoemission spectroscopy

Images of the basal plane of palladium ditelluride (PdTe2) taken with a scanning tunneling microscope are discussed with the aid of scanning tunneling spectroscopy (STS) and angle-resolved photoemission results taken from the same material. Two states associated with transitions into unoccupied bulk conduction bands are observed at 0.5 eV and 1.7 eV. The STS results compare well with theoretical calculations of the density of states of PdTe2. In addition, the position of features in the STS spectra are found to compare closely with peaks appearing in the photoemission spectra taken at normal emission and peaks in the inverse photoemission spectra taken at normal incidence. As well as identifying the tellurium atoms as the main source of tunneling current for low bias voltages, the STS results provide experimental evidence that the scanning tunneling microscope preferentially samples states that exist along the Gamma A symmetry line of the Brillouin zone in this material.