Size dependent optical properties of LaB6 nanoparticles enhanced by localized surface plasmon resonance

Lanthanum hexaboride nanoparticles, with high emission electrons in cathode materials and peculiar blocking near infrared wavelengths, were applied for many aspects. Based on the quasi-static approximation of Mie theory, the size dependent optical properties of LaB6 nanoparticles were researched, such as refractive index n(ω), extinction coefficient k(ω), reflectivity R(ω), absorption coefficient α(ω), and electron energy loss L(ω). Due to the localized surface plasmon resonance (LSPR), the extinction coefficient k(ω) and absorption coefficient α(ω) depended on the size, and the LSPR peaks red-shifted with sizes increased, which was different from that of bulk materials. In addition, electron energy-loss spectrum L(ω) showed electrons oscillation reinforced, since electrons absorbed the photon energy and generated resonance. Further, reflectivity R(ω) and refractive index n(ω) indicated that the light in near infrared region could not be propagated on the surface of LaB6 materials, which exhibited metallic behaviors. So the resonance peak of LaB6 nanoparticle was located in near-infrared region, making use of this property for solar control glazing and heat-shielding application.

The absorption spectrum α (ω) for different particle sizes of LaB6 nanoparticles (Due to localized surface plasmon resonance (LSPR), the absorption coefficient α(ω) depends on the size, and as the sizes increase the localized surface plasmon resonance (LSPR) peaks redshifted, which is different from that of bulk materials. The crystal structure of LaB6 is shown in the inset)Figure optionsDownload as PowerPoint slide