发表机构
Ames National Laboratory, US DOE, Iowa State University; Department of Physics and Astronomy, Iowa State University; Institute of Physics, University of São Paulo; Center for Advanced Radiation Sources, The University of Chicago; Advanced Photon Source, Argonne National Laboratory（艾姆斯国家实验室，美国能源部，爱荷华州立大学; 爱荷华州立大学物理与天文学系; 圣保罗大学物理研究所; 芝加哥大学高级辐射源中心; 阿贡国家实验室先进光子源）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过高压实验与计算，发现ReO3在菱方R-3c相中实现体超导电性（最大Tc约17.5 K），归因于强电子-声子耦合，并解释了更高压相超导消失的微观机制。
AI 中文摘要
理解晶格几何如何使氧化物产生超导电性仍是一个核心挑战。在此，我们报告了ReO3在高达80 GPa压力下的系统性研究。同步辐射X射线衍射、拉曼光谱、电输运、直流磁化率和第一性原理计算确立了压力诱导的结构转变序列，从立方Pm-3m相到Im-3相，随后出现菱方R-3c相，并伴随体超导电性，其最大超导转变温度起始值Tc约为17.5 K。直流磁化率和磁通陷阱磁化测量表明，体超导电性仅限于R-3c相占主导的压力范围。密度泛函理论计算显示，hR24-R-3c结构中存在强电子-声子耦合，低频Re振动和高频氧相关声子模式均有显著贡献，计算得到的Tc与实验值相当。在进一步压缩至约35-40 GPa以上时，粉末X射线衍射结果表明发生了对称性降低的结构转变。虽然实验衍射图谱最好用菱方衍生的R32类平均畸变来描述，且晶胞有效增大，但焓计算确定了由R-3c相声子不稳定性驱动的更低对称性mP16-P2/c结构。这种重构的高配位相在费米能级处态密度降低，电子-声子耦合减弱，计算Tc大幅降低，为高压相中体超导电性的消失提供了微观解释。这些结果表明，体超导电性在菱方结构中得以稳定，其中压力诱导的晶格重构通过协同的Re-O晶格动力学支持增强的电子-声子耦合。
英文摘要
Understanding how lattice geometry enables superconductivity in oxides remains a central challenge. Here, we report a systematic study of ReO3 up to 80 GPa. Synchrotron X-ray diffraction, Raman spectroscopy, electrical transport, dc magnetic susceptibility, and first-principles calculations establish a sequence of pressure-induced structural transitions, from cubic Pm-3m to Im-3 followed by the emergence of a rhombohedral R-3c phase accompanied by bulk superconductivity with a maximum Tc, onset ~17.5 K. DC magnetic susceptibility and trapped-flux magnetization measurements demonstrate that bulk superconductivity is confined to the pressure range where R-3c phase is dominant. Density functional theory calculations show strong electron-phonon coupling in the hR24-R-3c structure, with substantial contributions from both low-frequency Re vibrations and high-frequency oxygen-related phonon modes, yielding a calculated Tc comparable with the experiment. Upon further compression above ~35-40 GPa, powder X-ray diffraction results indicate a symmetry-lowering structural transition. Whereas the experimental diffraction patterns can be best described by a rhombohedral-derived R32-like average distortion with effective enlargement of the crystallographic unit cell, enthalpy calculations identify a lower-symmetry mP16-P2/c structure driven by phonon instability of the R-3c phase. This reconstructed higher-coordination phase has a reduced density of states at the Fermi level, weaker electron-phonon coupling, and a much lower calculated Tc, providing a microscopic explanation for the loss of bulk superconductivity in the higher-pressure phase. These results show that bulk superconductivity is stabilized within the rhombohedral structure, where pressure-induced lattice reconstruction supports enhanced electron-phonon coupling through cooperative Re-O lattice dynamics.
Comments29 pages, 8 figures
Journal refS. Huyan, R.F.S. Penacchio, L.-L. Wang et al., Materials Today Physics, 67, 102206 (2026)
DOI：10.1016/j.mtphys.2026.102206
