Naslov
Analytical modeling of electron energy loss spectroscopy of graphene : Ab initio study versus extended hydrodynamic model
(Analytical modeling of electron energy loss spectroscopy of graphene: Ab initio study versus extended hydrodynamic model)

Autori
Djordjević, Tijana ; Radović, Ivan ; Despoja, Vito ; Lyon, Keenan ; Borka, Duško ; Mišković, Zoran

Izvornik
Ultramicroscopy (0304-3991) 184 (2018), A; 134-142

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
EELS ; graphene ; optical conductivity

Sažetak
We present an analytical modeling of the electron energy loss (EEL) spectroscopy data for free-standing graphene obtained by scanning transmission electron microscope. The probability density for energy loss of fast electrons traversing graphene under normal incidence is evaluated using an optical approximation based on the conductivity of graphene given in the local, i.e., frequency-dependent form derived by both a two-dimensional, two-fluid extended hydrodynamic (eHD) model and an ab initio method. We compare the results for the real and imaginary parts of the optical conductivity in graphene obtained by these two methods. The calculated probability density is directly compared with the EEL spectra from three independent experiments and we find very good agreement, especially in the case of the eHD model. Furthermore, we point out that the subtraction of the zero-loss peak from the experimental EEL spectra has a strong influence on the analytical model for the EEL spectroscopy data.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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