English

Unconventional superconductivity in the cage type compound Sc$_5$Rh$_6$Sn$_{18}$

Superconductivity 2019-01-23 v1

Abstract

We have examined the superconducting ground state properties of the caged type compound Sc5_5Rh6_6Sn18_{18} using magnetization, heat capacity, and muon-spin relaxation or rotation (μ\muSR) measurements. Magnetization measurements indicate type-II superconductivity with an upper critical field μ0Hc2(0)\mu_0H_{c2}(0) = 7.24 T. The zero-field cooled and field cooled susceptibility measurements unveil an onset of diamagnetic signal below TcT_{\bf c} = 4.4 K. The interpretation of the heat capacity results below TcT_{\bf c} using the α\alpha-BCS model unveils the value of α\alpha = 2.65, which gives the dimensionless ratio 2Δ(0)/kBTc\Delta(0)/k_B T_{\bf c} = 5.3, intimating that Sc5_5Rh6_6Sn18_{18} is a strong-coupling BCS superconductor. The zero-field μ\muSR measurements in the longitudinal geometry exhibit a signature of a spontaneous appearance of the internal magnetic field below the superconducting transition temperature, indicating that the superconducting state is characterized by the broken time-reversal symmetry (TRS). We have compared the results of broken TRS in Sc5_5Rh6_6Sn18_{18} with that observed in R5_5Rh6_6Sn18_{18} (R = Lu and Y).

Keywords

Cite

@article{arxiv.1901.05444,
  title  = {Unconventional superconductivity in the cage type compound Sc$_5$Rh$_6$Sn$_{18}$},
  author = {A. Bhattacharyya and D. T. Adroja and N. Kase and A. D. Hillier and A. M. Strydom and J. Akimitsu},
  journal= {arXiv preprint arXiv:1901.05444},
  year   = {2019}
}

Comments

6 pages, 4 figures. arXiv admin note: text overlap with arXiv:1411.6877