Designing multicomponent hydrides with potential high Tc superconductivity

• 成果类型: Article
• 署名作者: Denchfield, Adam; Park, Hyowon; Hemley, Russell J.
• 署名单位: University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; United States Department of Energy (DOE); Argonne National Laboratory; University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13649
• DOI: 10.1073/pnas.2413096121
• 发表日期: 2024-11-05
• 关键词: lanthanide hydrides; hydrogen; lattice

摘要

While hydrogen-rich materials have been demonstrated to exhibit high Tc superconductivity at high pressures, there is an ongoing search for ternary, quaternary, and more chemically complex hydrides that achieve such high critical temperatures at much lower pressures. First-principles searches are impeded by the computational complexity of solving the Eliashberg equations for large, complex crystal structures. Here, we adopt a simplified approach using electronic indicators previously established to be correlated with superconductivity in hydrides. This is used to study complex hydride structures, which are predicted to exhibit promisingly high critical temperatures for superconductivity. In particular, we propose three classes of hydrides inspired by the Fm3m RH3 structures that exhibit strong hydrogen network connectivity, as defined through the electron localization function. The first class [RH11X3Y] is based on a Pm3m structure showing moderately high Tc, where the Tc estimate from electronic properties is compared with direct Eliashberg calculations and found to be surprisingly accurate. The second class of structures [(RH11)2X6YZ] improves on this with promisingly high density of states with dominant hydrogen character at the Fermi energy, typically enhancing Tc. The third class [(R1H11)(R2H11)X6YZ] improves the strong hydrogen network connectivity by introducing anisotropy in the hydrogen network through a specific doping pattern. These design principles and associated model structures provide flexibility to optimize both Tc and the structural stability of complex hydrides.