Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Observation of Phase Transitions in Hydrogenated Y Films Via IR Emissivity Imaging



Jason Hattrick-Simpers, Ke Wang, Raymond Cao, Chun Chiu, Edwin J. Heilweil, Robert G. Downing, Leonid A. Bendersky


Direct observation of a sequence of phase transitions during hydrogenation of Y thin films has been realized through the use of in-situ isothermal IR emissivity measurements. The formation of different phases, α-Y(H), YH2 and YH3, has been identified based on observation of the changes in the slope of the IR emissivity vs. time curve during the hydrogen loading experiments. The presence of the appropriate phases was confirmed by ex-situ x-ray diffraction and Prompt Gamma Activation Analysis (PGAA). Transmission electron microscopy (TEM) demonstrated single crystal orientation relationships between the Al2O3 substrate, Ti buffer layer, the as-deposited Y film, as well as its hydrides. These results clearly demonstrate the power of IR emissivity imaging to monitor, in real time, the formation of hydride phases of both metallic and insulating character near the surface of a thin-film sample.
Journal of Alloys and Compounds
490 (2010)


hydrogen storage, Yttrium tri-hydride, Yttrium di-hydride, IR imaging
Created October 20, 2009, Updated November 10, 2018