01573nas a2200241 4500008004100000245009300041210006900134260002400203520077100227653001000998653003101008653001101039653001501050653002201065100002001087700002601107700002701133700002401160700002101184700002501205700002301230856007801253 2002 eng d00aStructural and Electronic Properties of Magnesium-3D Transition Metal Switchable Mirrors0 aStructural and Electronic Properties of Magnesium3D Transition M aGolden, COc12/20023 a
We have observed reversible mirror-to-transparent state switching in a variety of mixed metal thin films containing magnesium and first-row transition elements including Ni, Fe, Co, Mn, and Ti. The very large changes in both reflectance and transmittance on loading these films with hydrogen are accompanied by significant structural and electronic transformations. The valence states and coordination of metal atoms during hydrogen loading were followed using dynamic in situ transmissionmode X-ray absorption spectroscopy. Time-resolved Mg K-edge and Ni, Co, Mn, and Ti L-edge spectra reflect both reversible and irreversible changes in the metal environments. These spectra are compared to those of reference materials and to predictions from calculations.
10aEXAFS10aHydrogen storage materials10aNEXAFS10athin films10ax-ray diffraction1 aFarangis, Baker1 aNachimuthu, Ponnusamy1 aRichardson, Thomas, J.1 aSlack, Jonathan, L.1 aMeyer, Bruno, K.1 aPerera, Rupert, C.C.1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/structural-and-electronic-properties01355nas a2200193 4500008004100000245005500041210005400096260001200150300001400162490000700176520076500183100002700948700002400975700002500999700002101024700002001045700002301065856007301088 2001 eng d00aSwitchable Mirrors Based on Nickel-Magnesium Films0 aSwitchable Mirrors Based on NickelMagnesium Films c05/2001 a3047-30490 v783 aAn electrochromic mirror electrode based on reversible uptake of hydrogen in nickel magnesium alloy films is reported. Thin, magnesium-rich Ni-Mg films prepared on glass substrates by cosputtering from Ni and Mg targets are mirror-like in appearance and have low visible transmittance. Upon exposure to hydrogen gas or on cathodic polarization in alkaline electrolyte, the films take up hydrogen and become transparent. When hydrogen is removed, the mirror properties are recovered. The transition is believed to result from reversible formation of Mg2NiH4 and MgH2. A thin overlayer of palladium was found to enhance the kinetics of hydrogen insertion and extraction, and to protect the metal surface against oxidation.
1 aRichardson, Thomas, J.1 aSlack, Jonathan, L.1 aArmitage, Robert, D.1 aKostecki, Robert1 aFarangis, Baker1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/switchable-mirrors-based-nickel