1. Facile synthesis of palladium hydride via ionic gate-driven protonation using a deep eutectic solvent
- Author
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Gavello, Gaia, Tofani, Giorgio, De Fazio, Domenico, Lettieri, Stefania, Mezzetta, Andrea, Guazzelli, Lorenzo, Pomelli, Christian S., Gonnelli, Renato S., Piatti, Erik, and Daghero, Dario
- Subjects
Condensed Matter - Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter - Superconductivity - Abstract
Developing novel protocols for hydrogen (H) loading is crucial for furthering the investigation of hydrides as potential high-temperature superconductors at lower pressures compared to recent discoveries. Ionic gating-induced protonation (IGP) has emerged as a promising technique for H loading due to its inherent simplicity, but it can be limited in the maximum density of injected H when ionic liquids are used as a gating medium. Here, we demonstrate that large H concentrations can be successfully injected in both palladium (Pd) bulk foils and thin films (up to a stoichiometry PdH$_{0.89}$) by using a choline chloride-glycerol deep eutectic solvent (DES) as gate electrolyte and applying gate voltages in excess of the cathodic stability limit. The attained H concentrations are large enough to induce superconductivity in Pd, albeit with an incomplete resistive transition which suggests a strongly inhomogeneous H incorporation in the Pd matrix. This DES-based IGP protocol can be used as a guideline for maximizing H loading in different materials, although specific details of the applied voltage profile might require adjustments based on the material under investigation., Comment: 12 pages, 5 figures
- Published
- 2024