**4. References**

218 Advanced Aspects of Spectroscopy

at the temperatures 500ºC and 620ºC.

treatment or after ion irradiation of the surface.

**3. Conclusion** 

obtained by IS and AES.

**Author details** 

Vitaliy Tinkov

*Ukraine, Ukraine* 

Heating of Co-Cr-Mo alloy induces decreasing IL of surface plasmon as well as probability of their appearance in EELS spectra dependence on temperature at variation of the energy Е0. High–temperature heating of Co–Cr–Mo alloy promotes to increase the emission and background of secondary electrons in characteristic spectra, that did not allow us exactly to separate the peaks of plasma oscillations at small primary electron energy Е0 = 150 eV. As shown on Figure 13 for temperatures 500ºC and 620ºC the line of surface plasmon disappearances at Е0 > 350 eV and Е0 > 300 eV, respectively. At heating of alloy to Т = 790ºC the surface plasmon is detected only in range of the energy Е0 = 200 – 350 eV, however dependence Rs from Е0 decays quickly compared to other temperatures. Besides increasing the intensity line of plasmons with the increase of heating of Co–Cr–Mo alloy the observed a broadening of bulk plasmon line. The correlation between the damping of function Rs from Е0 and formation of concentration profile in the near surface region of alloy was established for the non–annealed Co–Cr–Mo alloy (see Figure 7). For the annealed alloy the surface plasmon detects in EELS spectra in the range of Е0 = 150 – 350 eV. This range of energy Е<sup>0</sup> corresponding to the near surface region where was observed the largest variation of alloy composition relative to bulk concentration. The similar situation occurs at heating to Т = 790ºC for which the alloy concentration in the near surface region comes towards to the bulk at energy Е0 > 300 eV. Only the qualitative the correlation between the damping function Rs from Е0 and comes towards to the bulk concentration are observes for the Co–Cr–Mo alloy

Low Electron Energy Loss Spectroscopy can be used as effective non-destructive method at investigation of physical-chemical properties materials in the nano-size near surface region. Ionization energy losses allows to investigation layer-by-layer concentration profile for the singe crystal alloys with monolayer resolution, element distribution on the depth for the polycrystalline alloys and study of kinetics of surface processes at thermo-induced

Plasmon excitations are very sensitive to structural and chemical state of surface and bulk and it can be used for study of electronic states of free electrons in the near surface region and influence of different kinetic processes on changing of electronic structure of materials. Analysis of intensity line of surface and bulk plasmons depending on primary electron energy E0 allows to define a surface-bulk interface when electron beam probes just near surface region with different physical-chemical properties as compared to the bulk material. These results have good correlation with data of surface composition on depth which

*Department of the Surface Atomic Structure and Dynamic, Institute for Metal Physics of NAS of* 

