2018 - Sustainable Industrial Processing Summit & Exhibition
4-7 November 2018, Rio Othon Palace, Rio De Janeiro, Brazil
| Plasmon Spectroscopy of the Transition Metal Films Surface Sergii Sidorenko1; M.a. Vasylyev2; S.m. Voloshko1; V.v. Yanchuk1; O.i. Kruglov1; 1IGOR SIKORSKY KYIV POLYTECHNIC INSTITUTE, Kyiv, Ukraine; 2G.V. KURDYUMOV INSTITUTE FOR METAL PHYSICS, Kyiv, Ukraine; PAPER: 177/Manufacturing/Regular (Oral) SCHEDULED: 12:35/Wed./Mar Azul (50/1st) ABSTRACT: Plasmon spectroscopy for the first time was used to analyze the surface of the nanosized transition metal films [1]. Multilayer Ni/Cu/Cr and Ni/Cu/V systems with a thickness of 25 nm layers, obtained by electron-beam deposition in a super-high vacuum of 10-7 Pa, were studied. The samples were irradiated with Ar<sup>+</sup> ions with a current density of 5 µA/cm<sup>2</sup> and an energy of 600 eV at doses of 2-1017 and 12-1017 ions/cm<sup>2</sup> and maintained in an atmosphere of atomic oxygen for 24 hours at 6-10-8 Pa in the electron spectrometry. The averaged values of the energy of the surface (E<sub>s</sub>) and bulk (E<sub>b</sub>) plasmons, the concentration of the conduction electrons involved in plasma oscillations, as well as the relative changes of the interplanar distances, are calculated [2]. The low-energy ion effects greatly improve the physico-chemical state of the sample's surface, since E<sub>s</sub> increases with increasing E<sub>b</sub>. At the same time, the conduction electrons concentration is noticeably reduced due to the formation of radiation defects of the vacancy type and the static relaxation of the type of "expansion" of the interplanar distances. Exposure in oxygen after ion bombardment reduces the indicated changes in the concentration of conduction electrons and reduces the manifestation of the effect of surface relaxation by ~6 times. Replacing the "lower" layer of Cr with the layer V in a three-layer system affects the results of quantitative analysis of the plasmon spectra of the "upper" Ni layer. This necessitates the consideration of the long-range effects of the transition metal layers that are applied to the substrate, for example, to improve adhesion (usually Cr or V), when interpreting the results of the plasmon spectroscopy of the nanosized film surfaces. The difference between the experimental data obtained from the theory of free electron gas, which is confirmed for massive samples of transition metals, can be caused by several reasons: the participation of not all valence electrons in collective vibrations; the influence on the energy of the plasmons by interband transitions; as well as the actual physical and chemical state of the film material surface [3]. References: [1] V.A. Tinkov, M.A. Vasylyev, G.G. Galstyan, Vacuum 85 (2011) 677-686. [2] Y. Wu, G. Li, J.P. Camden, Chem. Rev. 10 (2017) 124-131. [3] Y. Fujiyoshi, T. Nemoto, H. Kurata, Ultramicroscopy 175 (2017) 116-120. |
