Transformation of hexagonal Lu to cubic LuH${}_{2+x}$ single-crystalline films

Abstract

With the recent report of near ambient superconductivity at room temperature in the N-doped lutetium hydride (Lu-H-N) system, the understanding of cubic Lu-H compounds has attracted worldwide attention. Generally, compared to polycrystal structures with non-negligible impurities, the single-crystalline form of materials with high purity can provide an opportunity to show their hidden properties. However, the experimental synthesis of single-crystalline cubic Lu-H compounds has not been reported thus far. Here, we developed an easy way to synthesize highly pure LuH${}_{2+x}$ single-crystalline films by the post-annealing of Lu single-crystalline films (purity of 99.99%) in the H${}_2$ atmosphere. The crystal and electronic structures of films were characterized by X-ray diffraction, Raman spectroscopy, and electrical transport. Interestingly, Lu films are silver-white and metallic, whereas their transformed LuH${}_{2+x}$ films become purple-red and insulating, indicating the formation of an unreported electronic state of Lu-H compounds possibly. Our work provides a novel route to synthesize and explore more single-crystalline Lu-H compounds.

References in corpus (12)

• Absence of near-ambient superconductivity in LuH${}_{2\pm \text{x}}$N${}_y$
• High Tc superconductivity in heavy Rare Earth Hydrides: correlation between the presence of the f states on the Fermi surface, nesting and the value of Tc
• Superconductivity above 70 K observed in lutetium polyhydrides
• Pressure-induced color change in the lutetium dihydride LuH2
• Lu-H-N phase diagram from first-principles calculations
• The near room-temperature upsurge of electrical resistivity in Lu-H-N is not superconductivity, but a metal-to-poor-conductor transition
• Pressure induced color change and evolution of metallic behavior in nitrogen-doped lutetium hydride
• Future Study of Dense Superconducting Hydrides at High Pressure
• One-step epitaxy of high-mobility La-doped BaSnO3 films by high-pressure magnetron sputtering
• Leading components and pressure-induced color changes in N-doped lutetium hydride
• Pressure tuning of optical reflectivity in LuH2
• Electronic and magnetic properties of Lu and LuH${}_2$

Cited by in corpus (6)

• Observation of non-superconducting phase changes in LuH${}_{2\pm \text{x}}$N${}_y$
• Ab initio study of the structural, vibrational and optical properties of potential parent structures of nitrogen-doped lutetium hydride
• Electronic and magnetic properties of Lu and LuH${}_2$
• The Rise of Refractory Transition-Metal Nitride Films for Advanced Electronics and Plasmonics
• Anatomy of the band structure of the newest apparent near-ambient superconductor LuH${}_{3-x}$N${}_x$
• Unveiling a Novel Metal-to-Metal Transition in LuH2: Critically Challenging Superconductivity Claims in Lutetium Hydrides