films with controlled termination by MBE and determination of their electronic structure by ARPES

Utilizing the powerful combination of molecular-beam epitaxy (MBE) and angle-resolved photoemission spectroscopy (ARPES) we produce and study the effect of different terminating

layers on the electronic structure of the metallic delafossite PdCoO₂. Attempts to introduce unpaired electrons and synthesize new antiferromagnetic metals akin to the isostructural compound PdCrO₂ have been made by replacing cobalt with iron in PdCoO₂ films grown by MBE. Using ARPES, we observe similar bulk bands in these PdCoO₂ films with Pd-, CoO₂-, and FeO₂-termination. Nevertheless, Pd- and CoO₂-terminated films show a reduced intensity of surface states. Additionally, we are able to epitaxially stabilize PdFe_xCo_1−xO₂ films which show an anomaly in the derivative of the electrical resistance with respect to temperature at 20 K, but do not display pronounced magnetic order.