### Abstract

The surface excitation effect is investigated by using the quantum mechanical frame work of complex self-energy of electrons which interact with a bounded semi-infinite medium. In the self-energy formalism, differential inverse inelastic mean free path (DIIMFP) has contributions from bulk and surface plasmons. Monte Carlo simulation of the interaction of electrons with a solid medium and surface has been performed. The surface excitation parameter (SEP) is then obtained from the simulated reflection electron energy loss spectroscopy (REELS) spectra. The calculated SEP results by Monte Carlo simulation are compared with the previous calculations of total surface excitation probability, which was estimated by a numerical integration of surface term of DIIMFP. The contribution merely due to surface excitations towards REELS spectra is extracted by subtracting the two Monte Carlo simulated REELS spectra that based on the two models of electron inelastic scattering, i.e. a full surface model (SM) and a pure bulk model (BM). The surface excitations found to be significant at low energy losses and diminish at higher energy losses whereas the bulk plasmon contributions show opposite behavior and are negligible at lower energy losses. The average number of surface excitations is then evaluated by the computation of ratio of the integrated surface contribution to the elastic peak. The calculated results for Ag are found to be reasonably in agreement with our previous results for total probability of surface excitations and other reported experimental data for SEP. Surface correction factor (SCF) is calculated using SEP for several metals and is compared with the reported ratio of SCF with Ni sample as reference.

Original language | English |
---|---|

Pages (from-to) | 1236-1243 |

Number of pages | 8 |

Journal | Surface Science |

Volume | 603 |

Issue number | 9 |

DOIs | |

Publication status | Published - May 1 2009 |

### Fingerprint

### Keywords

- Electron solid interactions
- IMFP
- Monte Carlo
- REELS
- Surface excitation parameter
- Surface plasmon

### ASJC Scopus subject areas

- Surfaces and Interfaces
- Condensed Matter Physics
- Materials Chemistry
- Surfaces, Coatings and Films

### Cite this

*Surface Science*,

*603*(9), 1236-1243. https://doi.org/10.1016/j.susc.2009.03.007

**Quantification of surface effects : Monte Carlo simulation of REELS spectra to obtain surface excitation parameter.** / Salma, K.; Ding, Z. J.; Zhang, Z. M.; Zhang, P.; Tőkési, K.; Varga, D.; Toth, J.

Research output: Contribution to journal › Article

*Surface Science*, vol. 603, no. 9, pp. 1236-1243. https://doi.org/10.1016/j.susc.2009.03.007

}

TY - JOUR

T1 - Quantification of surface effects

T2 - Monte Carlo simulation of REELS spectra to obtain surface excitation parameter

AU - Salma, K.

AU - Ding, Z. J.

AU - Zhang, Z. M.

AU - Zhang, P.

AU - Tőkési, K.

AU - Varga, D.

AU - Toth, J.

PY - 2009/5/1

Y1 - 2009/5/1

N2 - The surface excitation effect is investigated by using the quantum mechanical frame work of complex self-energy of electrons which interact with a bounded semi-infinite medium. In the self-energy formalism, differential inverse inelastic mean free path (DIIMFP) has contributions from bulk and surface plasmons. Monte Carlo simulation of the interaction of electrons with a solid medium and surface has been performed. The surface excitation parameter (SEP) is then obtained from the simulated reflection electron energy loss spectroscopy (REELS) spectra. The calculated SEP results by Monte Carlo simulation are compared with the previous calculations of total surface excitation probability, which was estimated by a numerical integration of surface term of DIIMFP. The contribution merely due to surface excitations towards REELS spectra is extracted by subtracting the two Monte Carlo simulated REELS spectra that based on the two models of electron inelastic scattering, i.e. a full surface model (SM) and a pure bulk model (BM). The surface excitations found to be significant at low energy losses and diminish at higher energy losses whereas the bulk plasmon contributions show opposite behavior and are negligible at lower energy losses. The average number of surface excitations is then evaluated by the computation of ratio of the integrated surface contribution to the elastic peak. The calculated results for Ag are found to be reasonably in agreement with our previous results for total probability of surface excitations and other reported experimental data for SEP. Surface correction factor (SCF) is calculated using SEP for several metals and is compared with the reported ratio of SCF with Ni sample as reference.

AB - The surface excitation effect is investigated by using the quantum mechanical frame work of complex self-energy of electrons which interact with a bounded semi-infinite medium. In the self-energy formalism, differential inverse inelastic mean free path (DIIMFP) has contributions from bulk and surface plasmons. Monte Carlo simulation of the interaction of electrons with a solid medium and surface has been performed. The surface excitation parameter (SEP) is then obtained from the simulated reflection electron energy loss spectroscopy (REELS) spectra. The calculated SEP results by Monte Carlo simulation are compared with the previous calculations of total surface excitation probability, which was estimated by a numerical integration of surface term of DIIMFP. The contribution merely due to surface excitations towards REELS spectra is extracted by subtracting the two Monte Carlo simulated REELS spectra that based on the two models of electron inelastic scattering, i.e. a full surface model (SM) and a pure bulk model (BM). The surface excitations found to be significant at low energy losses and diminish at higher energy losses whereas the bulk plasmon contributions show opposite behavior and are negligible at lower energy losses. The average number of surface excitations is then evaluated by the computation of ratio of the integrated surface contribution to the elastic peak. The calculated results for Ag are found to be reasonably in agreement with our previous results for total probability of surface excitations and other reported experimental data for SEP. Surface correction factor (SCF) is calculated using SEP for several metals and is compared with the reported ratio of SCF with Ni sample as reference.

KW - Electron solid interactions

KW - IMFP

KW - Monte Carlo

KW - REELS

KW - Surface excitation parameter

KW - Surface plasmon

UR - http://www.scopus.com/inward/record.url?scp=65249186695&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=65249186695&partnerID=8YFLogxK

U2 - 10.1016/j.susc.2009.03.007

DO - 10.1016/j.susc.2009.03.007

M3 - Article

AN - SCOPUS:65249186695

VL - 603

SP - 1236

EP - 1243

JO - Surface Science

JF - Surface Science

SN - 0039-6028

IS - 9

ER -