TY - JOUR
T1 - High energy-resolution electron energy-loss spectroscopy study of the dielectric properties of bulk and nanoparticle LaB6 in the near-infrared region
AU - Sato, Yohei
AU - Terauchi, Masami
AU - Mukai, Masaki
AU - Kaneyama, Toshikatsu
AU - Adachi, Kenji
N1 - Funding Information:
The authors thank Mr. F. Sato for his skillful technical assistance. The present work was partly supported by a Grant-in-Aid for Scientific Research in Priority Area ‘New Materials Science Using Regulated Nano Space-Strategy in Ubiquitous Elements’ by the Ministry of Education, Culture, Sports, Science, and Technology of Japan (No. 19051002 ), and the KAZATO Research Foundation .
PY - 2011/7
Y1 - 2011/7
N2 - The dielectric properties of LaB6 crystals and the plasmonic behavior of LaB6 nanoparticles, which have been applied to solar heat-shielding filters, were studied by high energy-resolution electron energy-loss spectroscopy (HR-EELS). An EELS spectrum of a LaB6 crystal showed a peak at 2.0eV, which was attributed to volume plasmon excitation of carrier electrons. EELS spectra of single LaB6 nanoparticles showed peaks at 1.1-1.4eV depending on the dielectric effect from the substrates. The peaks were assigned to dipole oscillation excitations. These peak energies almost coincided with the peak energy of optical absorption of a heat-shielding filter with LaB6 nanoparticles. On the other hand, those energies were a smaller than a dipole oscillation energy predicted using the dielectric function of bulk LaB6 crystal. It is suggested that the lower energy than expected is due to an excitation at 1.2eV, which was observed for oxidized LaB6 area.
AB - The dielectric properties of LaB6 crystals and the plasmonic behavior of LaB6 nanoparticles, which have been applied to solar heat-shielding filters, were studied by high energy-resolution electron energy-loss spectroscopy (HR-EELS). An EELS spectrum of a LaB6 crystal showed a peak at 2.0eV, which was attributed to volume plasmon excitation of carrier electrons. EELS spectra of single LaB6 nanoparticles showed peaks at 1.1-1.4eV depending on the dielectric effect from the substrates. The peaks were assigned to dipole oscillation excitations. These peak energies almost coincided with the peak energy of optical absorption of a heat-shielding filter with LaB6 nanoparticles. On the other hand, those energies were a smaller than a dipole oscillation energy predicted using the dielectric function of bulk LaB6 crystal. It is suggested that the lower energy than expected is due to an excitation at 1.2eV, which was observed for oxidized LaB6 area.
KW - High energy-resolution electron energy-loss spectroscopy
KW - Optical absorption in the near-infrared region
KW - Optical properties of metal nanoparticle
KW - Solar-heat shielding filter
KW - Surface plasmon
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U2 - 10.1016/j.ultramic.2011.05.003
DO - 10.1016/j.ultramic.2011.05.003
M3 - Article
AN - SCOPUS:80051813315
SN - 0304-3991
VL - 111
SP - 1381
EP - 1387
JO - Ultramicroscopy
JF - Ultramicroscopy
IS - 8
ER -