A New Superconductor Parent Compound NaMn₆Bi₅ with Quasi-One-Dimensional Structure and Lower Antiferromagnetic-Like Transition Temperatures

Mn-based superconductors are very rare and their superconductivity has only been reported in three-dimensional MnP and quasi-one-dimensional KMn 6 Bi 5 and RbMn 6 Bi 5 with [Mn 6 Bi 5 ] − columns under high pressures. Here we report the synthesis, magnetism, electrical resistivity, and specific heat capacity of the newly discovered quasi-one-dimensional NaMn 6 Bi 5 . Compared with other A Mn 6 Bi 5 ( A = K, Rb, and Cs), NaMn 6 Bi 5 has abnormal Bi-Bi bond lengths and two antiferromagnetic-like transitions at 47.3 K and 51.8 K. Anisotropic resistivity and low-temperature non-Fermi liquid behavior are observed. Heat capacity measurement reveals that the Sommerfeld coefficient for NaMn 6 Bi 5 is unusually large. Using first-principles calculations, an unusual enhancement of density of states near the Fermi level is demonstrated for NaMn 6 Bi 5 . The features make NaMn 6 Bi 5 a more suitable platform to explore the interplay of magnetism and superconductivity.