1. Interface-enhanced superconductivity in multi-grain (FeSe)η(SrTiO3)1-η composites.
- Author
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Zhang, Huimin, Dong, Wenfeng, Meng, Qing-Long, Yin, Nan, Liu, Zhengmao, Lu, Xiaowei, Ge, Binghui, Li, Yuanzhao, Shi, Quan, Wang, Lili, Xue, Qi-Kun, Jiang, Peng, and Bao, Xinhe
- Subjects
SUPERCONDUCTIVITY ,TRANSMISSION electron microscopy ,X-ray microscopy ,SCANNING electron microscopy ,MOLE fraction - Abstract
Interface superconductivity, realized in multiple artificial crystalline heterostructures, is one of the most exciting directions to search for high-temperature superconductivity. In this work, we prepare bulk (FeSe)
η (SrTiO3 )1−η multi-grain composites by a simple facile liquid-phase compaction method using a spark-plasma-sintering technique. Combining transmission electron microscopy/scanning electron microscopy and x-ray diffraction investigations, we demonstrate that the composites consist of micron-scale SrTiO3 grains surrounded by [001]-compressed β-FeSe grains. Transport measurements for the composites with FeSe mole fraction η > 0.06 reveal that two superconducting channels, one Tc ∼ 13 K phase from FeSe/SrTiO3 interfaces and another Tc ∼ 7 K phase from FeSe grains, cooperatively induce macroscopic superconducting behavior with isotropic upper critical fields above 40 T. This work points out a straightforward method to enhance Tc in the multi-grain (FeSe)η (SrTiO3 )1−η composites by reducing the crystalline grains to nanoscale and finely tuning the stoichiometries of FeSe and SrTiO3 . [ABSTRACT FROM AUTHOR]- Published
- 2021
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