1. Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China 2. Zhejiang California International NanoSystems Institute, Zhejiang University, Hangzhou 310058, China 3. Collaborative Innovation Centre of Advanced Microstructures, Nanjing 210093, China
We synthesized a series of Nb2Pd1−xRuxS5 polycrystalline samples by a solid-state reaction method and systematically investigated the Ru-doping effect on superconductivity by transport and magnetic measurements. It is found that superconductivity is enhanced with Ru doping and is quite robust upon disorder. Hall coefficient measurements indicate that the charge transport is dominated by hole-type charge carriers similar to the case of Ir doping, suggesting multi-band superconductivity. Upon Ru or Ir doping, Hc2/Tc exhibits a significant enhancement, exceeding the Pauli paramagnetic limit value by a factor of approximately 4. A comparison of Tc and the upper critical field (Hc2) amongst the different doping elements on Pd site, reveals a significant role of spin–orbit coupling.
Q. Zhang, G. Li, D. Rhodes, A. Kiswandhi, T. Besara, B. Zeng, J. Sun, T. Siegrist, M. D. Johannes, and L. Balicas, Superconductivity with extremely large upper critical fields in Nb2Pd0.81S5, Sci. Rep. 3, 1446 (2013)
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S. Khim, B. Lee, K. Y. Choi, B. G. Jeon, D. H. Jang, D. Patil, S. Patil, R. Kim, E. S. Choi, S. Lee, J. Yu, and K. H. Kim, Enhanced upper critical fields in a new quasi-one-dimensional superconductor Nb2PdxSe5, New J. Phys. 15(12), 123031 (2013)
https://doi.org/10.1088/1367-2630/15/12/123031
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J. Zhang, J. K. Dong, Y. Xu, J. Pan, L. P. He, L. J. Zhang, and S. Y. Li, Superconductivity at 2.5 K in the new transition-metal chalcogenide Ta2PdxSe5, Supercond. Sci. Technol. 28(11), 115015 (2015)
https://doi.org/10.1088/0953-2048/28/11/115015
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Y. Lu, T. Takayama, A. F. Bangura, Y. Katsura, D. Hashizume, and H. Takagi, Superconductivity at 6 K and the violation of Pauli limit in Ta2PdxS5, J. Phys. Soc. Jpn. 83(2), 023702 (2014)
https://doi.org/10.7566/JPSJ.83.023702
Q. R. Zhang, D. Rhodes, B. Zeng, T. Besara, T. Siegrist, M. D. Johannes, and L. Balicas, Anomalous metallic state and anisotropic multiband superconductivity in Nb3Pd0.7Se7, Phys. Rev. B 88(2), 024508 (2013)
https://doi.org/10.1103/PhysRevB.88.024508
N. Zhou, X. Xu, J. R. Wang, J. H. Yang, Y. K. Li, Y. Guo, W. Z. Yang, C. Q. Niu, B. Chen, C. Cao, and J. Dai, Controllable spin-orbit coupling and its influence on the upper critical field in the chemically doped quasione- dimensional Nb2PdS5 superconductor, Phys. Rev. B 90(9), 094520 (2014)
https://doi.org/10.1103/PhysRevB.90.094520
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C. Y. Shen, B. Q. Si, H. Bai, X. J. Yang, Q. Tao, G. H. Cao, and Z. A. Xu, Pd site doping effect on superconductivity in Nb2Pd0.81S5, Europhys. Lett. 113(3), 37006 (2016)
https://doi.org/10.1209/0295-5075/113/37006
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C. Q. Niu, J. H. Yang, Y. K. Li, B. Chen, N. Zhou, J. Chen, L. L. Jiang, B. Chen, X. X. Yang, C. Cao, J. Dai, and X. Xu, Effect of selenium doping on the superconductivity of Nb2Pd(S1−xSex)5, Phys. Rev. B 88(10), 104507 (2013)
https://doi.org/10.1103/PhysRevB.88.104507
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https://doi.org/10.1038/nature06332
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https://doi.org/10.1103/PhysRevB.79.054521
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L. J. Li, Y. K. Luo, Q. B. Wang, H. Chen, Z. Ren, Q. Tao, Y. K. Li, X. Lin, M. He, Z. W. Zhu, G. H. Cao, and Z. A. Xu, Superconductivity induced by Ni doping in BaFe2As2 single crystals, New J. Phys. 11(2), 025008 (2009)
https://doi.org/10.1088/1367-2630/11/2/025008
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H. Yu, M. Zuo, L. Zhang, S. Tan, C. Zhang, and Y. Zhang, Superconducting fiber with transition temperature up to 7.43 K in Nb2Pd1−xS5 (0.6<x<1), J. Am. Chem. Soc. 135(35), 12987 (2013)
https://doi.org/10.1021/ja4062079
