Plasmonic applications of lossy transition metals

In the field of plasmonics, noble metals such as Au or Ag have been frequently utilized due to their strong plasmon resonance features arising from the Drude-like property of sp-electrons. On the other hand, transition metals such as platinum-group metals (PGMs) are usually not considered as a plasmonic material because of their weak plasmon resonances damped by localized d-electrons. It is, however, known that transition metals exhibit various unique functionalities due to the d-electrons. Therefore, if such functionalities are combined with plasmonic nano-systems, plasmonics may be extended to various research fields and applications.