An optical hydrogen sensor based on a Pd-capped Mg thin film wedge

✍ Scribed by V. Palmisano; M. Filippi; A. Baldi; M. Slaman; H. Schreuders; B. Dam

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 468 KB
• Volume: 35
• Category: Article
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2010.09.001

✦ Synopsis

We report the proof of concept of a thin film device with a one-to-one relationship between the H 2 partial pressure and the lateral progression of a visible optical change along a thin film multilayer 70 mm long. The device basically consists of a sensing Mg layer with a thickness gradient. It exploits the thickness dependence of the hydrogenation thermodynamics of Pd-capped Mg thin films. The optical change of the Mg layer during the metalehydride transition can be detected both in reflection and in transmission. This optical sensor allows a continuous measurement of hydrogen partial pressure in the range between 200 and 4000 Pa.