The influence of the proton irradiation on the thermally fluctuation-induced conductivity in Ca8.5La1.5(pt3As8)(Fe2As2)5 single crystal was investigatyed. The in-plane magnetoconductivity was measured up to H=13T. It is observed that the Tc was suppressed up to 30.3 from 32.5 K when the proton is irradiated whereas the amplitude of the fluctuation effect is the almost same in both samples. The results were analyzed by the Ullah and Dorsey scaling functions based on the Hartree approximation to the Ginzburg-Landau free energy, including the critical-fluctuation regime. In the pristine sample, the 3D-2D crossover in the fluctuation effect was observed near the Tc. When the 3D-2D occurs, it is newly found that there is a regime simultaneously described by 2D and 3D fluctuation behaviors. Meanwhile, the proton-irradiated sample showed the 3D fluctuation.
Origin of positive out-of-plane magnetoconductivity in overdoped Bi$_{1.6}$Pb$_{0.4}$Sr$_{2}$CaCu$_{1.96}$Fe$_{0.04}$O$_{8+δ}$
为了阐明赝能隙相图,包括过掺杂状态的高转变温度(高- $T_c$)的铜酸盐,我们必须了解的起源,观察到这些化合物的积极的面外磁导率(MC)。为此,在高达60 T的脉冲磁场下测量过掺杂的Bi $_{1.6}$ Pb $_{0.4}$ Sr $_{2}$ CaCu $_{1.96}$ Fe $_{0.04}$ O $_{8+δ}$(Bi-2212)单晶的面外电阻率$ρ_c(T,H)$。我们发现,除了赝能隙效应外,超导态密度(DOS)的耗尽效应在超导态的涨落区之下明显地出现,并且贡献在超导态中占主导地位。
Measurements of the fluctuation-induced in-plane magnetoconductivity at high reduced temperatures and magnetic fields in the iron arsenide BaFe(2-x)NixAs2
Comment on 'Temperature range of superconducting fluctuations above $T_c$ in YBa$_2$Cu$_3$O$_{7-δ}$ single crystals'
与Grbić等人(Phys. Rev. B 83,144508(2011))的起始假设相反,在这里我们将首先论证16 T的磁场不足以淬灭YBa $_2$ Cu $_3$ O $_{7-δ}$中Tc以上的所有超导涨落。然后,我们得出结论,通过他们的微波吸收测量这些作者实际上确定在16 T的交流波动磁导率,而不是零场交流介导,因为他们假装。因此,Grbić等人提出的超导涨落开始的温度T '将对应于在16 T的有限场效应在他们的实验中变得可测量的温度,并且实际的涨落开始将位于T'之上。这些结论也涉及到最近关于这一问题的有影响力的出版物,然后通过分析Grbić等人的一些文章得到证实,数据的理由高斯金兹伯格-朗道(GGL)方法的有限场(或Prange)波动制度。
Critical current anisotropy in Nd-1111 single crystals and the infuence of neutron irradiation
本文报道了NdFeAsO $_{0.65}$ F $_{0.35}$(Nd-1111)单晶的角分辨磁化强度测量。场依赖性的临界电流密度,$J_c$,是非单调的,在这些晶体在所有的取向和温度,由于鱼尾效应,这强烈影响的角度依赖性的$J_c$。在低场时,电流随着场从晶体学c轴倾斜而减小,但在高场时增加。在中间场,$J_c$的角度依赖性出现峰值。快中子辐照后,临界电流显著增强,鱼尾现象消失。然而,在低场和高场的不同电流各向异性仍然存在。我们讨论的各向异性缩放方法的框架中的数据,并提出了从占主导地位的钉扎在低场的低密度的大缺陷钉扎在高场的原始晶体的小缺陷。强钉扎占主导地位,在所有领域的照射后,和角度依赖性的$J_c$可以描述的各向异性缩放后,只有适当的扩展到这个钉扎制度。
Comparative study of the effects of electron irradiation and natural disorder in single crystals of SrFe$_{2}$(As$_{1-x}$P$_x$)$_2$ ($x=$0.35) superconductor
测量了SrFe $_2$(As $_{1-x}$ P $_x$)$_2$($x=$ 0.35)铁基超导体单晶的伦敦穿透深度$λ(T)$.研究了无序对转变温度、$T_c$和对$λ(T)$的影响。比较了退火控制的散射效应和2.5MeV电子辐照引入的人工无序效应。$λ(T)$的低温行为可以用幂律函数$Δλ(T)=AT^n$来描述,其中在原始退火样品中指数$n$接近于1,正如对于具有线节点的超导带隙所预期的那样。在$1.2 \times 10^{19}$ \ecm辐照后,指数$n$迅速增加,超过$n=$ 2的脏极限值,这意味着超导带隙中的节点是偶然的,可以通过无序提升。与$T_c$的指数$n$的变化是更强的照射晶体相比,在其中的无序生长缺陷的退火控制的晶体。我们讨论了不同类型的无序对带内和带间散射的不同影响。