Observation of hydrogen absorption and diffusion via quantum tunneling using metallic nanocontacts

2016 Fiscal Year Final Research Report

• Project/Area Number: 26600102
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: Kyushu University
• Principal Investigator: Kawae Tatsuya 九州大学, 工学研究院, 准教授 (30253503)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 金属中水素 / 液体水素 / 吸蔵・拡散 / 量子現象 / トンネル効果 / ナノコンタクト / 微分伝導測定

Outline of Final Research Achievements

We develop a new technique to detect hydrogen (H) atoms absorbed in metals using point-contact spectroscopy (PCS). When the contact regime is smaller than the mean free path of conduction electrons, the electrons are transferred through the steep potential drop without energy dissipation in the regime, and then lose their energy by inelastic electron scattering with excitations such as phonon. This leads to a peak anomaly, corresponding to the state density of the excitation, in the differential conductance spectra. In the present study, PCS is used for the detection of vibrational modes of absorbed H atoms.
Further, we found that inelastic electron scattering between the electrons and H atoms induces low temperature H absorption in palladium, vanadium and niobium nanocontacts from liquid H2. From the time and bias voltage dependences of the differential conductance spectra, we reveal that H absorption develops by applying bias voltage 30-50 mV.

Free Research Field

低温物理学