Filamentary superconductivity across the phase diagram of Ba(Fe,Co)2As2

• Main Authors: Hu, Tao, Panagopoulos, Christos, Xiao, H., He, S. K., Shen, B., Zhang, W. J., Xu, B., He, K. F., Han, J., Singh, Y. P., Wen, H. H., Qiu, X. G., Almasan, C. C.
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2013
• Subjects: DRNTU::Science::Chemistry::Physical chemistry::Magnetochemistry
• Online Access: https://hdl.handle.net/10356/95216; http://hdl.handle.net/10220/9238
• Institution: Nanyang Technological University

We show magnetotransport results on Ba(Fe1−xCox)2As2 (0.0⩽x⩽0.13) single crystals. We identify the low-temperature resistance step at 23 K in the parent compound with the onset of filamentary superconductivity (FLSC), which is suppressed by an applied magnetic field in a similar manner to the suppression of bulk superconductivity (SC) in doped samples. FLSC is found to persist across the phase diagram until the long-range antiferromagnetic order is completely suppressed. A significant suppression of FLSC occurs for 0.02<x<0.04, the doping concentration where bulk SC emerges. Based on these results and the recent report of an electronic anisotropy maximum for 0.02 ⩽x⩽ 0.04 [ Chu et al. Science 329 824 (2010)], we speculate that, besides spin fluctuations, orbital fluctuations may also play an important role in the emergence of SC in iron-based superconductors.