Figure 13.

Using a combination of EELS with Scanning Tunneling Electron Microscopy (STEM) high-angle annular dark field (HAADF) imaging, Herzing et al. [168] determined the plasmon resonance characteristics of refractory TiN thin films. The spectra were collected by traversing (a) the yellow line from the MgO substrate through the TiN thin film, and to the opposite protective Pt layer. The spectra (b) are integrated over ten pixels at the locations of each colored arrow and indicate the local inelastic scattering distribution at said locations. From this, the spectral features typical of the MgO substrate are noted with an increase in inelastic scattering at 7.5 eV. At the interface of the MgO, and TiN film, a sharp peak due to surface-plasmon scattering is observed. A bulk plasmon resonance is identified at 2.81 eV and a weaker surface plasmon resonance peak was detected at 2.05 eV. The results are further supplemented by comparisons to finite difference time-domain simulations based on the measured optical data, which provide bulk and surface plasmon resonances with reasonable agreement at 2.74 eV and 2.15 eV, respectively. Reprinted with permission from Ref [168] Copyright Elsevier (2016).