Effect of Hydrogenation on the Optical Properties of Cobalt and Tantalum Thin Films

Mangej Singh

Abstract


Thin films of cobalt are prepared using thermal evaporation method at pressure 10-5 torr. The hydrogen gas is introduced in chamber at different pressure from 0 Psi to 40 Psi to hydrogenate the films. Optical transmission is found to increase and optical absorption decrease with hydrogenation. The optical band gap in Co thin film is found to reduce with increasing of hydrogen pressure. The relative resistance in the Co thin films is also measured at different hydrogen pressures. It is found to vary nonlinear with increase in hydrogen pressure. The Raman Spectroscopy data show that intensity of Raman peaks is decrease with hydrogen pressure. The prepare film after hydrogenation shows the switchable behavior with variable optical band gap. The variation in optical band gap suggests electronic structural phase changes in thin films with hydrogenation. The surface morphology is carrying out for these films with and without hydrogenation by using optical microscope and Scanning Electron Microscope (SEM). Thin films of tantalum also prepared by using DC Sputtering unit and then hydrogenation at pressure 10 Psi. Transmission spectra and surface morphology also carry out for these films before and after hydrogenation. The optimum thickness for switchable mirrors observed was 170.5 nm in case of tantalum.

Keywords


Optical absorption; Transmission; Optical energy band gap; Surface Morphology; Resistivity

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References


Van der Sluis P., Ouwerkerk M., & Duine P.A. (1997). Optical switches based on magnesium lanthanide alloy hydrides. Appl. Phys. Lett., 70(25), 3356-3358.
van Gogh A.T.M., Nagengast D.G., Kooij E.S., Koeman N.J., Rector J.H., Griessen R., Flipse C.F.J., Smeets R.J.J.G.A.M. (2001). Structural, electrical, and optical properties of La1-zYzHx switchable mirrors. Phys. Rev. B, 63, 195105-25
Huiberts J.N., Griessen R., Rector J.H., Wijngaarden R.J., Dekker J.P., de Groot D.G., Koeman N.J. (1996). Yttrium and lanthanum hydride films with switchable optical properties, Nature (London), 3802, 31-34
Ramachandran R., & Menon R.K. (1998). An overview of industrial uses of hydrogen. Int J Hydrogen Energy, 23, 593-598.
Veziroglu T.N. (1999). Hydrogen energy system as a permanent solution to global energy environmental problems. Chem Ind, 53, 383-393.
Singh R.K, Lototsky M.V. & Srivastava O.N. (2007). Thermodynamical, structural, hydrogen storage properties and simulation studies of P–C isotherms of (La,Mm) Ni5-yFey. Int. J. Hydrogen Energy 32, 2971-2976.
Singh S.K, Singh A.K, & Srivastava O.N. (1985). Investigations on the structural and hydrogenation characteristics of LaNi5, HoNi5, GdNi5, SmNi5, MmNi5 and CFMmNi4.5Al0.5 thin films. Int. J. Hydrogen Energy 10, 523-529
Fukai Y. (2005). The Metal-Hydrogen System. Berlin/Heidelberg/New York: Springer. 1st ed. (1993)
Fukai Y. The Metal-Hydrogen System. Berlin/Heidelberg/New York: Springer. 2nd ed.
[Wiswall R in Alefeld G, V.¨olkl J..(1978). Hydrogen in Metals I. Berlin/Heidelberg/New York: Springer-Verlag eds. Topics in Applied Physics. 28, 201-242.
Richter D., Hempelmann R., Bowman R. C. (1992). Dynamics of hydrogen in intermetallic hydrides. In Hydrogen in Intermetallic Compounds II, Berlin/ Heidelberg/New York: Springer eds L.Schlapbach, 65, 97.
Dam B., Lokhorst A. C., Remhof A., Heijna M. C. R, Rector J. H., Borsa D., & Kerssemakers J. W. J. (2003). In situ preparation of YH2 thin films by PLD for switchable devices. J. Alloys and Compounds, 356-357, 526-529.
Latroch M. (2004). Structural and thermodynamic properties of metal hydrides used for energy storage. J. Phys.Chem. Solids, 65, 517-522.
Akiba E., (1999). Hydrogen-absorbing alloys. Curr. Opin. Solid State Mater. Sci. 4, 267–272.
Suda S. (1987). Metal hydrides, Int. J. Hydrogen Energy, 12, 323-331.
Goodell P. D, Sandrock G. D. & Huston E. L. (1980). Kinetic and dynamic aspects of rechargeable metal hydrides. J Less Common Met, 73, 135–142.
Bergman L. & Nemanich R. J. (1996). Raman Spectroscopy for Characterization of Hard, Wide-Bandgap Semiconductors: Diamond, GaN, GaAlN, AlN, BN, Annu. Rev. Mater. Sei. 26, 551.
Fukata N., Sasaki S. & Murakami K. (1997). Hydrogen molecules and hydrogen-related defects in crystalline silicon. Physical Review, B56, 6642-6647.
Borsa D. M., Gremaud R., Baldi R. A., Schreuders H., Rector J. H., Kooi B., Vermeulen P., Notten P. H. L., Dam B., Griessen R. (2007). Structural, optical, and electrical properties of MgyTi1-yHx thin films. Physical review B, 75, 205408.
Singh S. K., Singh A. K., & Srivastava O. N. (1985). Investigations on the structural and hydrogenation characteristics of LaNi5, HoNi5, GdNi5, SmNi5, MmNi5 and CFMmNi4.5Al0.5 thin films. Int. J. Hydrogen Energy, 10, 523-529.
Singh M., Vijay Y. K., Jain I. P. (1991). The temperature dependence of FeTi and FeTiSz thin films obliquely deposited for the hydrogen absorption-desorption mechanism. International Journal of Hydrogen Energy, 16, 485-490.
Singh M., Vijay Y. K., Jain I. P. (1991). The effect of selenium layer coating and temperature dependence on TiNi thin films obliquely deposited for the hydrogen absorption mechanism. International Journal of Hydrogen Energy, 16, 477-483.
Singh M., Vijay Y. K., Jain I. P. (1992). Effect of hydrogen absorption on electrical resistance and hall effect charge carrier concentration in FeTi, FeTiSz, TiNi and TiNiSez thin films. International Journal of Hydrogen Energy, 17, 29-35.
Adachi G., Niki K., Nagai H., Schiokawe J. (1983). The effect of hydrogen absorption on the electrical resistivities of LaNi5 and MmNi4.5Mn0.5 films (Mm misch metal). J. less common Metals, 88, 213-216.
H. Sakaguchi, Y. Yagi, N. Taniguchi, G. Adachi, J. Shiokawa (1987). Effects of hydrogen absorption on the electrical resistivity of LaCo5 films and the determination of the hydrogen content in the films. J. less common metals, 135, 137-146.
Richardson T. J., Slack J. L., Armitage R. D. Rubin M. D. (2001). Switchable mirrors based on nickel–magnesium films. Appl. Phys. Lett., 78, 3047-3049.
Bastide J. P., Bonnetot B., Letoffe J. M., Claudy P. (1980). Polymorphisme de l’hydrure de magnesium sous haute pression. Mater. Res. Bull, 15, 1215.
Bortz M., Bertheville B., Bottger G., Yvon K. (1999). Structure of the high pressure phase y-MgH2 by neutron powder diffraction. J. Alloys Compd, 287, L4-L6.
Orgschulte A., Westerwaal R. J., Rector J. H., Dam B., Griessen R. (2004). The effect of the Strong Metal-Support Interaction on hydrogen sorption kinetics of Pd-capped switchable mirrors. Physical Review B, 70, 155414
Harada S., Yokota S., Ishii Y., Shizuka Y., Kanazawa M. Fukai Y. (2005). A relation between the vacancy concentration and hydrogen concentration in the Ni–H, Co–H and Pd–H systems. Journal of alloys and compound, 404-406, 247.
Kume T., Ohura H., Takeichi T., Sasaki S., Shimizu H., Ohmura A., Machida A., Watanuki T., Aoki K. Takemura K. (2008). Raman and optical absorption studies of rare-earth hydrides under high pressure. Journal of physics: conference series, 121, 042011.
Kala S., Mehta B. R. (2008). Hydrogen-induced electrical and optical switching in Pd capped Pr nanoparticle layers. Bull. Mater. Sci. 31(3), 225-231
Azofeifa D., Clark N., Vargas W. (2005). Optical and electrical properties of terbium films as a function of hydrogen concentration. Phys.stat.sol (b). 242(10), 2005-09
Bao S., Tajima K., Yamada Y., Okada M., Yoshimura K. (2008). Magnesium–titanium alloy thin-film switchable mirrors.Solar Energy Materials and solar cells, 92, 224




DOI: http://dx.doi.org/10.3968%2Fj.est.1923847920130502.858

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