Figure 7.

(A) Extinction spectra of hematite-Au core-shell nanorice with different shell thicknesses. Two plasmon peaks are observed for each sample. The plasmons at longer and shorter wavelengths are the longitudinal and transverse plasmons, respectively. The samples measured are monolayers of isolated nanoshells immobilized on polyvinylpyridine (PVP)-glass slides; (B) A SEM image of a monolayer of nanorice particles (shell thickness of 13.1 (1.1 nm) on a PVP-glass slide; (C) Calculated far-field extinction spectra of the nanorice with incident polarization along the longitudinal and (inset) transverse axis of a nanorice particle using finite difference time domain (FDTD). The nanorice particle employed for the FDTD simulations is composed of a hematite core with longitudinal diameter of 340 nm and transverse diameter of 54 nm surrounded by a 13-nm-thick Au shell. Near-field profile of the nanorice under resonance excitations: (D) incident polarization along the longitudinal axis, λ_ex = 1160 nm; (E) incident polarization along the transverse axis, λ_ex = 860 nm. Reproduced with permission from [73]. Copyright American Chemical Society, 2006.