High energy-resolution electron energy-loss spectroscopy study of the dielectric properties of bulk and nanoparticle LaB6 in the near-infrared region

► The dielectric properties of LaB6 nanoparticles applied to solar heat-shielding filters were studied by HR-EELS. ► Plasmon peak energies of the LaB6 nanoparticles were almost equal to optical absorption energy of a heat-shielding filter. ► From this result, near-infrared optical absorption of the filter is due to the surface dipole mode of the nanoparticles.