%0 Journal Article %J Journal of Applied Physics %D 1999 %T Refractive Index Changes of Pd-Coated Magnesium Ianthanide Switchable Mirrors Upon Hydrogen Insertion %A Klaus von Rottkay %A Michael D. Rubin %A Peter A. Duine %X

The optical effect upon insertion of hydrogen into Pd-coated magnesium lanthanide switchable mirrors is investigated in terms of the changes of their complex refractive indices. A significant change in the optical constants of LnMg layers is seen between the as-deposited state and the dehydrided state after one cycle. Furthermore, the optical effect of switching the Pd cap layer to a PdH cap layer was determined. It is shown that the Pd layer mainly limits the visible transmittance of the hydrided stack to about 35%-40%. Whereas the extinction coefficient of dehydrided LnMg layers at 550 nm is between 2.2 and 3.1, it is as low 10-4 as in the transparent state. This is of great promise to applications requiring large optical contrast (e.g., optical switches).

%B Journal of Applied Physics %V 85 %P 408-413 %8 01/1999 %G eng %N 1 %1

Windows and Daylighting Group

%2 LBNL-41976 %& 408 %R 10.1063/1.369399 %0 Journal Article %J Electrochimica Acta %D 1998 %T Effect of Hydrogen Insertion on the Optical Properties of PD-Coated Magnesium Lanthanides %A Klaus von Rottkay %A Michael D. Rubin %A Franck Michalak %A Robert D. Armitage %A Thomas J. Richardson %A Jonathan L. Slack %A Peter A. Duine %X

Metallic magnesium lanthanide thin films upon insertion of hydrogen transform to a highly transparent hydride phase. With a Pd overlayer, the transformation can be produced either by electrochemical insertion of hydrogen or by exposing the film to hydrogen gas. Unlike amorphous oxide electrochromics, the transformation is accompanied by a large change in visible reflectance (about 50%). The optical switching effect in these materials is investigated in terms of changes in the complex refractive index as determined by variable-angle spectroscopic ellipsometric and normal-incidence radiometric measurements over the solar spectrum. Furthermore the optical effect of converting the Pd caplayer to Pd-H was determined. It is shown that the pd layer limits the visible transmittance of the hyrdrided stack to about 35-40%. Whereas the extinction coefficient of the dehydrided LnMg-layers at 550 nm is between 2.2 and 3.1, it is as low as 10-4 in the transparent state.

%B Electrochimica Acta %C London, U.K. %8 9/1998 %G eng %L LBNL-42277 %1

Windows and Daylighting Group

%2 LBNL-42277