论文标题
在等值掺杂的$β$ -THRH $ _ {1-x} $ ir $ _ {x} $ ge中的结构不稳定性的边缘增强超导性
Enhancement of superconductivity on the verge of a structural instability in isovalently doped $β$-ThRh$_{1-x}$Ir$_{x}$Ge
论文作者
论文摘要
$β$ - thrhge是Thrhge的高温多晶型物，是众所周知的铁磁超导体URHGE的同源性。然而，与urhge相反，$β$ - thrhge是非磁性的，并且在244 K处进行不完整的结构相变，然后在3.36 K以下进行超导的过渡。在这里，我们在这里表明，通过抑制结构过渡，IR替换为RH替代了RH的强大增强超导管性。在$ x $ = 0.5的情况下，结构过渡消失的情况下，$ t _ {\ rm c} $最大达到6.88 k。正如热力学分析以及电阻性数据分析所暗示的，超导性的增强与在此IR浓度下的结构量子关键点的距离有关。第一原理计算表明，IR掺杂对费米水平附近的电子带分散的影响很小。 $β$ -THRH $ _ {1-x} $ ir $ _ {x} $ ge因此提供了一个出色的平台来研究含肌动剂化合物中超导性和结构量子差异性之间的相互作用。
$β$-ThRhGe, the high-temperature polymorph of ThRhGe, is isostructural to the well-known ferromagnetic superconductor URhGe. However, contrary to URhGe, $β$-ThRhGe is nonmagnetic and undergoes an incomplete structural phase transition at 244 K, followed by a superconducting transition below 3.36 K. Here we show that the isovalent substitution of Ir for Rh leads to a strong enhancement of superconductivity by suppressing the structural transition. At $x$ = 0.5, where the structural transition disappears, $T_{\rm c}$ reaches a maximum of 6.88 K. The enhancement of superconductivity is linked to the proximity to a structural quantum critical point at this Ir concentration, as suggested by the analysis of thermodynamic as well as resistivity data. First principles calculations indicate that the Ir doping has little effect on the electronic band dispersion near the Fermi level. $β$-ThRh$_{1-x}$Ir$_{x}$Ge thus provides an excellent platform to study the interplay between superconductivity and structural quantum criticality in actinide-containing compounds.
