Funct. Mater. 2019; 26 (2): 267-275.

doi:https://doi.org/10.15407/fm26.02.267

Multifunctional ceramics LaB6-SiC-B4C of eutectic composition: thermionic properties

A.Taran1, O.Kyslytsyn1, D.Voronovych1, O.Podshyvalova1, S.Ordan'yan2, D.Nesmelov2

1National Aerospace University Kharkiv Aviation Institute, 17 Chkalov Str., 61070 Kharkiv, Ukraine
2Saint-Petersburg State Institute of Technology (Technical University), 26 Moskovsky Ave., 190013 Saint-Petersburg, Russian Federation

Abstract: 

The article presents the results of thermionic studies (temperature dependences of the thermionic current density and the electron work function, Schottky lines to current-voltage characteristics) of LaB6-SiC-B4C multifunctional ceramics eutectic composition obtained by free sintering. The obtained data indicate a substantially low emission activity of both the entire emitting surface of the studied composite and the individual LaB6 grains on its surface as compared with the individual lanthanum hexaboride. Based on the X-ray phase analysis and X-ray energy dispersive microanalysis, it was concluded that the observed decrease in the emission activity is caused by carbonization of the entire surface due to thermal decomposition of SiC into carbon and silicon.

Keywords: 
lanthanum hexaboride, silicon carbide, thermionic emission, thermionic current density, electron work function.

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References: 

1. A.Taran, D.Voronovich, S.Plankovskyy et al., IEEE T. Electron Dev., 56, 812 (2009). https://doi.org/10.1109/TED.2009.2015615

2. S.Ordanyan, D.Nesmelov, S.Vikhman, Refract. Techn. Cer., No. 6, 2 (2006).

3. S.Ordanyan, D.Nesmelov, A.Taran, Refract. Techn. Ceram., No. 6, 3 (2013).

4. V.Lankau, H.-P.Martin, R.Hempel-Weber et al., J. Electron, Mater., 39, 1809 (2010). https://doi.org/10.1007/s11664-010-1129-0

5. V.Domnich, S.Reynaud, R.A.Haber, M.Chhowalla, J. Am. Ceram. Soc., 94, 3605 (2011). https://doi.org/10.1111/j.1551-2916.2011.04865.x

6. D.Voronovich, A.Taran, N.Shitsevalova et al., Solid State Sci., 14, 1624 (2012). https://doi.org/10.1016/j.solidstatesciences.2012.04.009

7. D.Voronovich, A.Taran, N.Shitsevalova et al., Solid State Phenom., 257, 152 (2017). https://doi.org/10.4028/www.scientific.net/SSP.257.152

8. L.N.Dobretsov, M.V.Gomoyunova, Emission Electronics, Israel Program for Scientific Translations, Jerusalem (1971).

9. G.G.Gnesin, G.S.Oleinik, L.N.Okhremchuk et al., Powder Metall. Met. C., 9, 406 (1970).

10. M.Wiets, M.Weinelt, T.Fauster, Phys. Rev. B, 68, 125321 (2003). https://doi.org/10.1103/PhysRevB.68.125321

11. C.He, Z.Li, W.Wang, Surf. Rev. Lett., 19, 1250040 (2012). https://doi.org/10.1142/S0218625X12500400

12. H.E.Gallagher, J. Appl. Phys., 40, 44 (1969). https://doi.org/10.1063/1.1657092

13. A.J.Van Bommel, J.E.Crombeen, A.Van Tooren, Surf. Sci., 48, 463 (1975). https://doi.org/10.1016/0039-6028(75)90419-7

14. Luxmi, R.M.Feenstra, Doctoral Thesis, Carnegie Mellon University, Pittsburgh, PA 15213 (2010).

15. G.S.Oleinik, N.V.Danilenko, Rus. Chem. Rev., 66, 553 (1997). https://doi.org/10.1070/RC1997v066n07ABEH000286

16. L.I.Mirkin, Handbook of X-Ray Analysis of Polycrystalline Materials, Springer Verlag, Berlin (2012).

17. CRC Handbook of Chemistry and Physics, ed. by D.R.Lide, CRC Press, Boca Raton, FL (2005).

18. G.V.Pavlinsky, Fundamentals of X-Ray Physics, Cambridge Intern. Sci. Publ., Cambridge, UK (2008).

19. V.S.Fomenko, Handbook of Thermionic Properties, Plenum Press Data Division, New York (1966). https://doi.org/10.1007/978-1-4684-7293-6

20. R.J.Wilson, J. Appl. Phys., 37, 2261 (1966). https://doi.org/10.1063/1.1708797

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