1. Superconductivity in Sm-doped CaFe 2 As 2 single crystals
- Author
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Bin-Bin Ruan, Tong Liu, Qi Guo, Qing-Ge Mu, Genfu Chen, Bo-Jin Pan, Dong-Yun Chen, Jia Yu, Zhi-An Ren, and Xiao-Chuan Wang
- Subjects
Quenching ,Superconductivity ,Phase transition ,Flux method ,Ionic radius ,Materials science ,Condensed matter physics ,Doping ,General Physics and Astronomy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Lattice constant ,Electrical resistivity and conductivity ,Condensed Matter::Superconductivity ,0103 physical sciences ,010306 general physics ,0210 nano-technology - Abstract
In this article, the Sm-doping single crystals Ca1 − x Sm x Fe2As2 (x = 0 ~ 0.2) were prepared by the CaAs flux method, and followed by a rapid quenching treatment after the high temperature growth. The samples were characterized by structural, resistive, and magnetic measurements. The successful Sm-substitution was revealed by the reduction of the lattice parameter c, due to the smaller ionic radius of Sm3+ than Ca2+. Superconductivity was observed in all samples with onset T c varying from 27 K to 44 K upon Sm-doping. The coexistence of a collapsed phase transition and the superconducting transition was found for the lower Sm-doping samples. Zero resistivity and substantial superconducting volume fraction only happen in higher Sm-doping crystals with the nominal x > 0.10. The doping dependences of the c-axis length and onset T c were summarized. The high-T c observed in these quenched crystals may be attributed to simultaneous tuning of electron carriers doping and strain effect caused by lattice reduction of Sm-substitution.
- Published
- 2016