Title | Hafnium-an optical hydrogen sensor spanning six orders in pressure. |
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Authors | Boelsma, C.; Bannenberg, L.J.; van Setten, M.J.; Steinke, N.J.; van Well, A.A.; Dam, B. |
Journal | Nat Commun |
DOI | 10.1038/ncomms15718 |
Abstract |
Hydrogen detection is essential for its implementation as an energy vector. So far, palladium is considered to be the most effective hydrogen sensing material. Here we show that palladium-capped hafnium thin films show a highly reproducible change in optical transmission in response to a hydrogen exposure ranging over six orders of magnitude in pressure. The optical signal is hysteresis-free within this range, which includes a transition between two structural phases. A temperature change results in a uniform shift of the optical signal. This, to our knowledge unique, feature facilitates the sensor calibration and suggests a constant hydrogenation enthalpy. In addition, it suggests an anomalously steep increase of the entropy with the hydrogen/metal ratio that cannot be explained on the basis of a classical solid solution model. The optical behaviour as a function of its hydrogen content makes hafnium well-suited for use as a hydrogen detection material. |
Hafnium-an optical hydrogen sensor spanning six orders in pressure.