Optical switching properties of Pd--Ni thin-film top-capped switchable mirrors

Abstract

Switchable mirrors based on magnesium--nickel alloy thin films capped with catalytic Pd--Ni alloy thin films were prepared by a DC magnetron sputtering method. Their composition, structure and surface morphology were studied by XPS, XRD and AFM. Herein, the optical switching properties and durability of the switchable mirrors were investigated by varying the Ni content in the Pd--Ni alloys. Comparing pure Pd catalyst with Pd--Ni top-capped switchable mirrors, the latter show better hydrogenation and dehydrogenation kinetics, and the speed of hydrogen desorption is obviously improved with increasing Ni content in the Pd--Ni alloy. The Pd--Ni capped switchable mirrors also have better optical switching durability. The catalytic Pd layer with the addition of Ni does not influence the transmittance (hydride state) and reflectance (metallic state) of the switchable mirrors. In addition, replacing Pd with Pd--Ni alloy decreases the cost of the switchable mirrors: employing nickel in the alloy Pd_89.2Ni_10.8 can save about 11% use of Pd. Therefore, the Pd--Ni alloy can provide a cheaper catalytic thin film, and it is expected to have applications in energy-saving windows, hydrogen sensors and hydrogen storage materials.

Keywords

magnesium alloy thin film / hydrogen storage material / Pd--Ni alloy / smart window / energy-saving material

References

[1] Richardson T J, Slack J L, Armitage R D, . Switchable mirrors based on nickel–magnesium films. Applied Physics Letters, 2001, 78(20): 3047-3049

[2] Yoshimura K, Yamada Y, Okada M. Optical switching of Mg-rich Mg–Ni alloy thin films. Applied Physics Letters, 2002, 81(25): 4709-4711

[3] Bao S, Tajima K, Yamada Y, Color-neutral switchable mirrors based on magnesium–titanium thin films. Applied Physics A: Materials Science & Processing, 2007, 87(4): 621-624

[4] Bao S, Yamada Y, Tajima K, New switchable mirror based on magnesium–niobium thin film. Japanese Journal of Applied Physics (Part 2), 2007, 46(1-3): L13-L15

[5] Bao S, Tajima K, Yamada Y, . Magnesium–titanium alloy thin-film switchable mirrors. Solar Energy Materials and Solar Cells, 2008, 92(2): 224-227

[6] Yamada Y, Bao S, Tajima K, . Optical properties of switchable mirrors based on magnesium–calcium alloy thin films. Applied Physics Letters, 2009, 94(19): 191910 (3 pages)

[7] Yoshimura K, Yamada Y, Bao S, . Preparation and characterization of gasochromic switchable-mirror window with practical size. Solar Energy Materials and Solar Cells, 2009, 93(12): 2138-2142

[8] Yoshimura K, Bao S, Yamada Y, . Optical switching property of Pd-capped Mg–Ni alloy thin films prepared by magnetron sputtering. Vacuum, 2006, 80(7): 684-687

[9] Yoshimura K, Yamada Y, Bao S, Degradation of switchable mirror based on Mg–Ni alloy thin film. Japanese Journal of Applied Physics, 2007, 46(7A): 4260-4264

[10] Bao S, Tajima K, Yamada Y, . Metal buffer layer inserted switchable mirrors. Solar Energy Materials and Solar Cells, 2008, 92(2): 216-223

[11] Bao S, Yamada Y, Okada M, Titanium-buffer-layer-inserted switchable mirror based on Mg–Ni alloy thin film. Japanese Journal of Applied Physics, 2006, 45(20-23): L588-L590

[12] Bao S, Yamada Y, Okada M, . The effect of polymer coatings on switching behavior and cycling durability of Pd/Mg–Ni thin films. Applied Surface Science, 2007, 253(14): 6268-6272

[13] Bao S, Tajima K, Yamada Y, . Polytetrafluoroethylene (PTFE) top-covered Mg–Ni switchable mirror thin films. Materials Transactions, 2008, 49(8): 1919-1921

[14] Miyamoto M, Mai T, Oumi Y, . Effect of adhesion of metals on deterioration of Pd and Pd alloy membranes. Journal of Alloys and Compounds, 2013, 577: 445-450

[15] Ou Y J, Si W W, Yu G, . Nanostructures of Pd–Ni alloy deposited on carbon fibers for sensing hydrogen. Journal of Alloys and Compounds, 2013, 569: 130-135

[16] Lee E, Lee J M, Lee E, . Hydrogen gas sensing performance of Pd–Ni alloy thin films. Thin Solid Films, 2010, 519(2): 880-884

[17] Vegard L. The constitution of the mixed crystals and the filling of space of the atoms. Zeitschrift fur Physik, 1921, 5: 17-26

[18] Bao S, Yamada Y, Tajima K, . Effect of deposition conditions on the response and durability of an Mg₄Ni film switchable mirror. Vacuum, 2008, 83(3): 486-489

[19] Alefeld G, Voelkl J. Hydrogen in Metals I and II. Berlin: Springer-Verlag, 1978

[20] Chen N, Yang H A, Caron A, . Glass-forming ability and thermoplastic formability of a Pd₄₀Ni₄₀Si₄P₁₆ glassy alloy. Journal of Materials Science, 2011, 46(7): 2091-2096

[21] Roa F, Way J D, McCormick R L, . Preparation and characterization of Pd–Cu composite membranes for hydrogen separation. Chemical Engineering Journal, 2003, 93(1): 11-22

[22] Huang T C, Wei M C, Chen H I. Preparation of palladium–silver alloy composite membranes for hydrogen permeation. Chemical Engineering Communications, 2002, 189(9): 1262-1282

[23] Timofeyev N I, Bersenyova F N, Gromov V I. Change of mechanical-properties of palladium and its alloys with silver by hydrogen action. The Physics of Metals and Metallography, 1981, 51(2): 412-421

[24] Yamada Y, Tajima K, Okada M, . Dehydrogenation process of Mg–Ni based switchable mirrors analyzed by in situ spectroscopic ellipsometry. Solar Energy Materials and Solar Cells, 2012, 99: 84-87

[25] Tajima K, Hotta H, Yamada Y, . Mg–Ni thin-film composition dependence of durability of electrochromic switchable mirror glass in simulated environment. Solar Energy Materials and Solar Cells, 2011, 95(12): 3370-3376

[26] Yoshimura K, Tajima K, Yamada Y, . Stress in switchable mirror thin film resulting from gasochromic switching. Japanese Journal of Applied Physics, 2010, 49(7): 075701

Acknowledgements

This study was financially supported by the National Natural Science Foundation of China (Grant Nos. 51032008, 51272271 and 51172265) and the National Key Basic Research Program (NKBRP, 2009CB939904).

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg