Influence of Electronic Structure of Nanoclusters on a Quantum Yield of Photoemission of Magnesium Alloys

V. G. Tkachenko, I. M. Maksymchuk, A. I. Kondrashev, I. I. Shulyak

I. M. Frantsevich Institute for Problems in Materials Science, NAS of Ukraine, 3 Academician Krzhyzhanovsky Str., UA-03142 Kyiv, Ukraine

Received: 07.10.2003. Download: PDF

The first experimental evidences are obtained by the mechanical spectroscopy, which yield forming the pair defects, i.e. primary nanoclusters of alloying element (AE)—excess vacancy (EV) at the early (pre-precipitate) stage in segregated solid solutions of as-cast eutectic alloys of Mg—Ba system. At the later stages, the clustering rate is increased by the presence of EV and completed by the stress rearrangement of AE—EV nanoclusters into magnesium clusters Mg$_n$ alloyed by the emission-active Ba$_m$ additions. It is noteworthy that thin structure of electron spectra is theoretically calculated for (Mg$_{16}$Ba$_2$) clusters using the first principles by the linearized augmented plane-wave (FLAPW) method with a complete approach for crystal-potential approximation of electronic structure of the x-ray photoelectron spectra (XPS) observed for massive (bulk) Mg—2% Ba (Mg$_{0,94}$Ba$_{0,06}$) alloy. Change of thin structure of XPS, occurrence of chemical shifts in Auger electron spectra (AES), and amplification of paramagnetic susceptibility of Mg—Ba alloys show that, as alloying element, Ba eliminates the minimum on a curve of electron density of states, $N(E)$, which is typical for the IIA subgroup semibrittle light metals, and raises the local density of engaged states near the Fermi surface ($E_{F}$). As revealed, embedded Mg$_{n}$Ba$_{m}$ clusters are responsible for hybridization of chemical bounds in segregated solid solutions with stabilizing the new hybrid $s$-, $p$-, $d$-electron configurations of clusters properly keeping their property to operate as emission-active centres raising a stable quantum yield of the photoemission. High quantum efficiency of the Mg—Ba alloys in a near UV-range of spectrum is explained by the surface-bulk character of the photoemission effect for eutectic alloys with clusterized structure having effective (at structural defects) mutual solubility of components (Mg and Ba).

Keywords: photoemission, work function, structure clusterization, electronic structure.

PACS: 61.46.+w, 62.25.+g, 62.40.+i, 71.15.Ap, 73.30.+y, 79.60.Jv


Citation: V. G. Tkachenko, I. M. Maksymchuk, A. I. Kondrashev, and I. I. Shulyak, Influence of Electronic Structure of Nanoclusters on a Quantum Yield of Photoemission of Magnesium Alloys, Usp. Fiz. Met., 5, No. 3: 313—344 (2004) (in Russian), doi: 10.15407/ufm.05.03.313

References (28)  
  1. V. G. Tkachenko, I. N. Maksimchuk, V. V. Shklover et al., Appl. Phys. A, 62: 285 (1996). Crossref
  2. V. I. Trefilov, V. G. Tkachenko, I. N. Maksimchuk, V. V. Shklover et al., Dokl. RAN, 340, No. 1: 48 (1995).
  3. V. I. Trefilov, V. G. Tkachenko, I. N. Maksimchuk et al., Dokl. RAN, 340, No. 2: 185 (1995).
  4. V. G. Tkachenko, Physical Fundamentals of Forming and Recovery of Properties of Rare Metals, Light and Precise Alloys (Kiev: Naukova Dumka: 1996) (in Russian); V. G. Tkachenko, Strength Physics of Less-Common Metals and Their Alloys (London: Cambridge Int. Sci. Publish.: 2002) (ISBN 189-832-6576) (in press).
  5. N. A. Soboleva, Itogi nauki i tekhniki (Moskva: 1976), vol. 6, p. 5.
  6. R. S. Busk, J. Metall/Trans. AIME, 4, No. 2: 207 (1952).
  7. V. K. Grigorovich, Metallicheskaya svyaz' i struktura metallov (Moskva: Nauka: 1988).
  8. A. P. Shpak, A. M. Korduban, V. V. Trachevskiy, N. S. Slobodyanik, Teoreticheskaya i eksperimental'naya khimiya, t. 36, No. 5: 267 (2000).
  9. P. Blaha, K. Schwarz, and J. Luitz, A Full Potential Linearized Augmented Plane Wave Packed for Calculating Crystal Properties (Wien: Karlheinz Schwarz–Techn. Universität: 1999).
  10. V. G. Bar'yakhtar, A. N. Timoshevski, V. K. Soolshenko, and A. N. Yaresko, J. Magnetism and Magnetic Materials, 140–144: 115 (1995). Crossref
  11. V. G. Tkachenko, V. A. Tatarenko, I. I. Schuljak et al., Metallofiz. Noveishie Tekhnol., 23, No. 3: 367 (2001).
  12. V. G. Tkachenko, D. M. Levin, V. I. Trefilov et al., Metallofiz. Noveishie Tekhnol., 23, No. 5: 699 (2001).
  13. V. G. Tkachenko, A. I. Kondrashev, V. I. Lazarenko et al., Dokl. RAN, 367, No. 5: 632 (1999).
  14. L. E. Davies et al., Handbook of Auger Electron Spectroscopy (Physical Electronics Division, Perkin-Elmer Corp. USA: 1978).
  15. Yu. N. Vesnin, Khimiya v interesakh ustoychivogo razvitiya, No. 8: 61 (2000).
  16. V. V. Nemoshkalenko, V. N. Antonov, V. T. Aleshin, Elektronnaya struktura metallov ikh splavov i intermetallicheskikh soedineniy (Kiev: Nauk. dumka: 1979), p. 3.
  17. V. N. Bugaev, N. K. Lashuk, V. A. Tatarenko, V. G. Tkachenko, V. I. Trefilov, Metallofizika, 8, No. 5: 33 (1986).
  18. B. Noble, S. J. Harris, and K. Dinsdale, J. Mater. Sci., 17: 461 (1982). Crossref
  19. V. G. Tkachenko, I. N. Maksimchuk, V. V. Friezel et al., Int. J. Hydrogen Energy, 21: 1091 (1996). Crossref
  20. V. G. Tkachenko, I. N. Maksimchuk, L. I. Kolesnic et al., Int. J. Hydrogen Energy, 21, No. 11/12: 1105 (1996). Crossref
  21. V. M. Bugaev, V. A. Tatarenko, V. G. Tkachenko, and I. N. Maksimchuk, Int. J. Hydrogen Energy, 24: 135 (1999). Crossref
  22. J. C. Bruyere et al., Thin Solid Films, 221, No. 1–2: 65 (1992). Crossref
  23. V. G. Tkachenko, I. I. Shuljak, A. M. Strutinsky et al., Int. J. Hydrogen Energy (2002) (in press).
  24. R. Nesper and G. J. Miller, J. Alloys and Compounds, 197: 109 (1993). Crossref
  25. P. Hausler et al., Mater. Sci. and Eng., A133: 115 (1991). Crossref
  26. G. V. Lashkarev, Magnitnaya vospriimchivost' tverdykh tel, ne obladayushchikh magnitnym poryadkom (Preprint IPM NANU 97-7, Kiev) (1997).
  27. T. M. Lifshits, N. G. Kokina, N. M. Politova, Radiotekhnika i elektronika, 5, No. 8: 1267 (1960).
  28. V. G. Tkachenko, I. N. Maksimchuk, and V. V. Shklover, Physical Principles for Creation of High Current Pulsed Photoemitters with Laser Excitation on the Base of Binary Metallic Alloys (Preprint 94-10, Kiev) (1994).
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  2. V. G. Tkachenko, Usp. Fiz. Met. 10, 103 (2009).