Superconductivity at 32 K in single crystal Rb$_{0.78}$Fe$_2$Se$_{1.78}$}

A. F. Wang; J. J. Ying; Y. J. Yan; R. H. Liu; X. G. Luo; Z. Y. Li; X. F. Wang; M. Zhang; G. J. Ye; P. Cheng; Z. J. Xiang; X. H. Chen

doi:10.1103/physrevb.83.060512

arXiv · 1012.5525

Superconductivity at 32 K in single crystal Rb$_{0.78}$Fe$_2$Se$_{1.78}$}

A. F. Wang·J. J. Ying·Y. J. Yan·R. H. Liu·X. G. Luo·Z. Y. Li·X. F. Wang·M. Zhang·G. J. Ye·P. Cheng·Z. J. Xiang·X. H. Chen

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Abstract

We successfully grew the high-quality single crystal of Rb$_{0.78}$Fe$_2$Se$_{1.78}$, which shows sharp superconducting transition in magnetic susceptibility and electrical resistivity. Resistivity measurements show the onset superconducting transition ($T_{\rm c}$) at 32.1 K and zero resistivity at 30 K. From the low-temperature iso-magnetic-field magnetoresistance, large upper critical field $H_{\rm c2}$(0) has been estimated as high as 180 T for in-plane field and 59 T for out-of-plane field. The anisotropy $H^{ab}_{\rm c2}$(0)/$H^{c}_{\rm c2}$(0) is around 3.0, right lying between those observed in K$_x$Fe$_2$Se$_2$ and Cs$_x$Fe$_2$Se$_2$.

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A. F. Wang, J. J. Ying, Y. J. Yan, R. H. Liu, X. G. Luo, Z. Y. Li, X. F. Wang, M. Zhang, G. J. Ye, P. Cheng, Z. J. Xiang, X. H. Chen. 2010-12-26. Superconductivity at 32 K in single crystal Rb$_{0.78}$Fe$_2$Se$_{1.78}$}. https://doi.org/10.1103/physrevb.83.060512

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