Doping dependence of the pinning efficiency in K-doped Ba122 single crystals prior to and after fast neutron irradiation
Doping dependence of the pinning efficiency in K-doped Ba122 single crystals prior to and after fast neutron irradiation
复制标题
快中子辐照前后 K 掺杂 Ba122 单晶钉扎效率的掺杂依赖性
DOI：
10.1088/1361-6668/ab2b51
复制
发表时间：
2019
影响因子：
3.6
通讯作者：
Eisterer M
中科院分区：
文献类型：
--
作者：
Kagerbauer D;Ishida S;Mishev V;Song D;Ogino H;Eisaki H;Nakajima M;Iyo A;Eisterer M
一个尖锐的峰值中观察到的掺杂依赖的临界电流密度，JC，在钾掺杂的Ba 122单晶。这种行为是在相反的掺杂的转变温度，Tc，其变化更平稳地围绕其最大值的依赖性。我们进行了快中子辐照的晶体，以找出J c峰是否从固有的属性或特定的缺陷景观的结果。已知快中子会引入高达几纳米大小的缺陷，这已被证明比原始晶体中的晶体缺陷更有效地用于通量钉扎。我们发现，在J c的峰值转移到更高的掺杂水平后，照射，加宽，大致遵循的Tc曲线的形状。此外，在辐照晶体中观察到的JC和Tc之间的幂律，这可以解释以前在铁基超导体中观察到的基本参数和Tc之间的关系。这种幂律不适用于原始晶体，这表明J c的掺杂依赖性的结果从增强的钉扎效率在下掺杂区域的相图。
A sharp peak was observed in the doping dependence of the critical current density, J c, in potassium doped Ba122 single crystals. This behavior is in contrast to the doping dependence of the transition temperature, T c, which varies much more smoothly around its maximum. We performed fast neutron irradiation on the crystals in order to find out whether the J c peak results from intrinsic properties or the particular defect landscape. Fast neutrons are known to introduce defects up to a size of a few nanometers, which have proven to be more efficient for flux pinning than the crystallographic defects in the pristine crystals. We find that the peak in J c shifts to higher doping levels after the irradiation, broadens, and roughly follows the shape of the T c curve. Moreover, a power law between J c and T c is observed in the irradiated crystals, which can be explained by relations between fundamental parameters and T c observed previously in iron-based superconductors. This power law does not hold for the pristine crystals which indicates that the doping dependence of J c results from an enhanced pinning efficiency in the under-doped area of the phase diagram.