Real-time detection of hydrogen absorption and desorption in metallic palladium using vibrating wire method

A vibrating wire (VW) method was applied to investigate the hydrogen absorption and desorption properties of palladium. At room temperature, a considerable shift in resonance frequency was successfully observed in VW spectra under H2 gas exposure. The shift is reversible in the initial stage of the exposure and is attributed to changes in the density and Young s modulus of the VW sensor. Irreversibility of the shift because of embrittlement is detected after a sufficient exposure time. H absorption is slowed down enormously at T = 200 K owing to suppression of the thermal activation process.