Intrinsic pinning on structural domains in underdoped single crystals of Ba(Fe[subscript 1−x]Co[subscript x])[subscript 2]As[subscript 2]
Intrinsic pinning on structural domains in underdoped single crystals of Ba(Fe[subscript 1−x]Co[subscript x])[subscript 2]As[subscript 2]
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DOI：
10.1103/physrevb.80.174517
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发表时间：
2009-09
影响因子：
3.7
通讯作者：
R. Prozorov;M. Tanatar;N. Ni;A. Kreyssig;S. Nandi;S. Bud’ko;A. Goldman;P. Canfield
中科院分区：
文献类型：
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作者：
R. Prozorov;M. Tanatar;N. Ni;A. Kreyssig;S. Nandi;S. Bud’ko;A. Goldman;P. Canfield
研究了Ba（Fe{sub 1-x}Co{sub x}）{sub 2} As 2单晶中x值跨越整个掺杂相图时的临界电流密度。对于在x=0.058处具有峰值的稍微欠掺杂的晶体，发现了显著的增强。使用偏振光成像，X射线衍射和磁性测量的组合，我们将这种行为与正交相结构域上的固有钉扎。畴壁在整个样品厚度上沿涡旋方向延伸，并充当延伸的钉扎中心。随着x的增加，由于正交畸变的减少，畴结构变得更加缠结和精细。这导致能量景观具有有利于钉扎的迷宫状空间调制。这一发现表明，铁基磷属元素化物超导体，其特征在于高值的转变温度，高的上临界场，和低的各向异性可能固有地具有相对高的临界电流密度。
Critical current density was studied in single crystals of Ba(Fe{sub 1-x}Co{sub x}){sub 2}As2 for the values of x spanning the entire doping phase diagram. A noticeable enhancement was found for slightly underdoped crystals with the peak at x=0.058. Using a combination of polarized-light imaging, x-ray diffraction and magnetic measurements we associate this behavior with the intrinsic pinning on structural domains in the orthorhombic phase. Domain walls extend throughout the sample thickness in the direction of vortices and act as extended pinning centers. With the increasing x domain structure becomes more intertwined and fine due to a decrease in the orthorhombic distortion. This results in the energy landscape with mazelike spatial modulations favorable for pinning. This finding shows that iron-based pnictide superconductors, characterized by high values of the transition temperature, high upper critical fields, and low anisotropy may intrinsically have relatively high critical current densities.