  Using nanometer spatial resolution electron-energy loss spectroscopy (EELS),
energy dispersive X-ray spectroscopy (EDS), and cathodoluminescence (CL)
mapping, we demonstrate that Au alloys containing a poor plasmonic metal (Pd)
can nevertheless sustain multiple size-dependent localized surface plasmon
resonances and observe strong field enhancement at Pd-rich tips, where the
composition is in fact least favorable for plasmons. These Au/Pd stellated
nanocrystals are also involved in substrate and interparticle coupling, as
unraveled by EELS tilt series.
