Study of topological nature of superconducting and normal states of RhPb₂

Recently, RhPb₂ was reported to be as a candidate of topological superconductor from the result of band calculation [1]. However, there has been so far no attempt to test it experimentally. According to the Rh-Pb binary phase diagram [2] the intermetallic compound RhPb₂ grows through peritectic reaction incongruently from the melt between 320^○C and 640^○C. We have tried to grow the single crystal by using the vertical pulling mechanism in a mirror furnace. It is clearly found that many single crystallites with a thin, long plate-like shape grow from the melt of RhPb₄. The preliminary X-ray diffraction analysis showed that the structure is similar to the β-PdBi₂ with the tetragonal symmetry with lattice parameters of a=3.40 Å and c=12.82 Å. In order to study the superconducting topological nature of RhPb₂, we perform the resistivity, the critical currents, the critical fields H_c1 and H_c2 measurements.

[1] J. F. Zhang et al., Phys. Rev. B 99 (2019) 045110.
[2]“Phase Equilibria, Crystallographic and Thermodynamic Data of Binary Alloy, Pb-Rh (Lead-Rhodium)", Landolt-Börnstein -Group IV Physical Chemistry 5I (1998).