非中心对称结构重费米子材料CeRhGe3压致超导电性的发现以及反铁磁相与超导相之间的异常关系的发现数据集

非常规超导体中通常是当反铁磁相被抑制后，超导转变出现在反铁磁相的相边界区域，这也表明磁涨落在非常规超导的形成中起到重要作用。重费米子化合物CeTX3家族具有I4mm的空间群结构，意味着这些家族成员的晶体结构缺少空间对称性。除了CeCoSi3处于混合价态外，其它成员在常压下均表现为反铁磁的基态。在压力的作用下CeRhSi3、CeIrSi3、CeCoGe3、CeIrGe3都表现为超导转变出现在反铁磁序被抑制的边缘。我们采用压力的方法将该家族中最后一个非超导化合物CeRhGe3压致为超导体。并发现轨道耦合强度的增观察CeRhGe3的高压相图，其反铁磁转变温度并不是连续下降到零，而是在一定的压力范围内几乎随压力不变，对CeRhGe3的电阻曲线正常态进行拟合，得到其残余电阻和指数n随压力的变化，发现在临界压力（Pc）附近，指数n=1，意味着费米液体行为到非费米液体行为的转变。高压X射线吸收谱显示CeRhGe3中Ce的平均价态随着压力的升高而升高。低温电阻标度分析的方法分析了价态扰动在CeRhGe3压致超导中的作用进行了分析,结果显示CeRhGe3确实发生了压力引起的价态的不稳定性。扰动会对低温物性产生重要的影响，这些结果表明高压下CeRhGe3中反铁磁相和超导相之间的异常关系与临界价态不稳定性密切相关。这些研究结果不仅突出了价态涨落对Ce基重费米子化合物压致超导电性的影响，而且为验证或者发展理论模型提供了实验依据。数据量27.5MB。In unconventional superconductors, superconductivity typically emerges at the phase boundary region of the antiferromagnetic phase after the latter has been suppressed, which indicates that magnetic fluctuations play a crucial role in the formation of unconventional superconductivity. The heavy fermion compound family CeTX₃ adopts the space group I4mm, implying that the crystal structures of the members in this family lack spatial symmetry. Except for CeCoSi₃ which is in a mixed valence state, all other members exhibit an antiferromagnetic ground state under ambient pressure. Under applied pressure, CeRhSi₃, CeIrSi₃, CeCoGe₃ and CeIrGe₃ all exhibit superconductivity emerging at the edge where their antiferromagnetic order is suppressed. We used the pressure method to induce superconductivity in CeRhGe₃, the last non-superconducting compound in this family. By investigating the high-pressure phase diagram of CeRhGe₃, we found that its antiferromagnetic transition temperature does not decrease continuously to zero, but remains nearly constant with increasing pressure over a certain pressure range, along with the enhancement of orbital coupling strength. We fitted the normal-state resistance curves of CeRhGe₃ to obtain the variations of residual resistance and exponent n with pressure, and found that near the critical pressure (Pc), the exponent n=1, which indicates a transition from Fermi liquid behavior to non-Fermi liquid behavior. High-pressure X-ray absorption spectroscopy shows that the average valence state of Ce in CeRhGe₃ increases with rising pressure. We analyzed the role of valence fluctuations in the pressure-induced superconductivity of CeRhGe₃ using low-temperature resistance scaling analysis, and the results confirm that pressure-induced valence instability indeed occurs in CeRhGe₃. Valence fluctuations exert a significant influence on low-temperature physical properties. These results demonstrate that the anomalous relationship between the antiferromagnetic phase and superconducting phase in high-pressure CeRhGe₃ is closely related to critical valence instability. These research findings not only highlight the impact of valence fluctuations on the pressure-induced superconductivity of Ce-based heavy fermion compounds, but also provide experimental evidence for verifying or developing theoretical models. Data size: 27.5 MB.

搜集汇总

背景与挑战

背景概述

该数据集聚焦于非中心对称结构重费米子材料CeRhGe3，通过高压实验成功诱导出超导电性。研究发现其反铁磁相与超导相之间存在异常关系，并与临界价态不稳定性密切相关，为理解重费米子化合物中的超导机制提供了实验依据。