通过测量脉冲磁场（$\sim$ 60 T）和直流磁场（$\sim$ 14 T）下的电阻率，确定了T1 $_{0.58}$ Rb $_{0.42}$ Fe $_{1.72}$ Se $_2$单晶的上临界场$μ_0H_{c2}(T_c)$。发现$\textbf{H}$、$\parallel$、$c$的$H_{c2}$随温度的降低而线性增加，达到$μ_0H_{c2}^{\textbf{H}\parallel c}(0\textrm{K})\simeq60$ T。另一方面，对于$\textbf{H}$ $\perp$ $c$（$μ_0H_{c2}^{\textbf{H}\perp c}$（18 K）$\simeq$ 60 T），观察到具有强凸曲率的较大$μ_0H_{c2}(0\textrm{K})$。该化合物在$T_c$周围显示出中等的上临界场各向异性，但随着温度的降低而降低。基于Werthamer-Helfand-Hohenberg（WHH）方法的上临界场分析表明，$μ_0H_{c2}(0\textrm{K})$对$\textbf{H}$ $\parallel$ $c$是轨道限制的，但自旋顺磁性效应对$\textbf{H}$ $\perp$ $c$的对破缺可能起重要作用.所有这些实验观察结果都与铁磷属元素化物超导体非常相似，表明铁基超导体的统一方案。此外，超导转变显着扩大后，施加磁场，表明强烈的热涨落效应在超导状态的T1 $_{0.58}$ Rb $_{0.42}$ Fe $_{1.72}$ Se $_2$。得到的涡旋运动的热激活能与1111型铁磷属元素的热激活能一致。
英文摘要：
The upper critical field $μ_0H_{c2}(T_c)$ of Tl$_{0.58}$Rb$_{0.42}$Fe$_{1.72}$Se$_2$ single crystals has been determined by means of measuring the electrical resistivity in both a pulsed magnetic field ($\sim$60T) and a DC magnetic field ($\sim$14T). It is found that $H_{c2}$ linearly increases with decreasing temperature for $\textbf{H}$$\parallel$$c$, reaching $μ_0H_{c2}^{\textbf{H}\parallel c}(0\textrm{K})\simeq60$ T. On the other hand, a larger $μ_0H_{c2}(0\textrm{K})$ with a strong convex curvature is observed for $\textbf{H}$$\perp$$c$ ($μ_0H_{c2}^{\textbf{H}\perp c}$(18K)$\simeq$60T). This compound shows a moderate anisotropy of the upper critical field around $T_c$, but decreases with decreasing temperature. Analysis of the upper critical field based on the Werthamer-Helfand-Hohenberg (WHH) method indicates that $μ_0H_{c2}(0\textrm{K})$ is orbitally limited for $\textbf{H}$$\parallel$$c$, but the effect of spin paramagnetism may play an important role on the pair breaking for $\textbf{H}$$\perp$$c$. All these experimental observations remarkably resemble those of the iron pnictide superconductors, suggesting a unified scenario for the iron-based superconductors. Moreover, the superconducting transition is significantly broadened upon applying a magnetic field, indicating strong thermal fluctuation effects in the superconducting state of Tl$_{0.58}$Rb$_{0.42}$Fe$_{1.72}$Se$_2$. The derived thermal activation energy for vortex motion is compatible with those of the 1111-type iron pnictides.
Thermally activated energy and critical magnetic fields of SmFeAsO$_{0.9}$F$_{0.1}$
本文研究了新近发现的SmFeAsO $_{0.9}$ F $_{0.1}$超导体在高达9.0 T的磁场中的热激活磁通流和涡旋玻璃转变。用两种分析方法对热激活能进行了分析，一种是常规的常用方法，另一种更接近于理论描述。从这两种方法确定的热活化能值进行了讨论和比较。此外，几个临界磁场确定的电阻率测量和讨论。
Directional-dependent thermally activated motion of vortex bundles and theory of anomalous Hall effect in type-II conventional and high-Tc superconductors
Doping dependence of the upper critical field, superconducting current density and thermally activated flux flow activation energy in polycrystalline CeFeAsO1-xFx superconductors
