Scanning Tunneling Microscopy Study on Delafossites PdCoO$_{\mathrm{2}}$ and PdCrO$_{\mathrm{2}}$.

There is a resurge of interests on Delafossite such as PdCoO$_{\mathrm{2}}$, which have layered two-dimensional electrons of Pd with exceptionally high conductivity separated by oxide layers. In this compound there are recent reports that electron transport is in the hydrodynamic regime. Another member of the Delafossite family, PdCrO$_{\mathrm{2}}$ has also been of considerable interest because of its complex spin ordering in the CrO$_{\mathrm{2}}$ layers as clarified by scattering experiments, which could be responsible for its intriguing magnetotrasnport properties. Here, we will report high-resolution scanning tunneling microscopy and spectroscopic mapping of both PdCoO$_{\mathrm{2}}$ and PdCrO$_{\mathrm{2}}$ Delafossites. On both compounds, we study scattering interference of electrons from defects and relate our results to surface band structure measurements by ARPES studies. By contrasting our results on these two compounds, we aim to determine how neighboring oxide layer with magnetism influences electrons in the two-dimensional Pd layer.