A new quasi-one-dimensional superconductor parent compound NaMn$_6$Bi$_5$ with lower antiferromagnetic transition temperatures

TL;DR

This paper reports the synthesis and characterization of NaMn$_6$Bi$_5$, a new quasi-one-dimensional Mn-based compound with lower antiferromagnetic transition temperatures, offering a promising platform for exploring Mn-based superconductivity.

Contribution

It introduces NaMn$_6$Bi$_5$ as a novel compound with unique magnetic and electronic properties, expanding the family of AMn$_6$Bi$_5$ materials and providing insights into their potential for superconductivity.

Findings

NaMn$_6$Bi$_5$ exhibits two decoupled antiferromagnetic transitions at 47.3 K and 52.3 K.

The compound shows anisotropic resistivity and non-Fermi liquid behavior at low temperatures.

First-principles calculations reveal a distinct density of states and an enhancement near the Fermi level.

Abstract

Mn-based superconductor is rare and recently reported in quasi-one-dimensional KMn$_6$Bi$_5$ with [Mn$_6$Bi$_5$]-columns under high pressure. Here we report the synthesis, magnetic properties, electrical resistivity, and specific heat capacity of the newly-discovered quasi-one-dimensional NaMn$_6$Bi$_5$ single crystal. Compared with other AMn$_6$Bi$_5$ (A = K, Rb, and Cs), NaMn$_6$Bi$_5$ has larger intra-column Bi-Bi bond length, which may result in the two decoupled antiferromagnetic transitions at 47.3 K and 52.3 K. The relatively lower antiferromagnetic transition temperatures make NaMn$_6$Bi$_5$ a more suitable platform to explore Mn-based superconductors. Anisotropic resistivity and non-Fermi liquid behavior at low temperature are observed. Heat capacity measurement reveals that NaMn$_6$Bi$_5$ has similar Debye temperature with those of AMn$_6$Bi$_5$ (A = K and Rb), whereas the Sommerfeld coefficient is unusually large. Using first-principles calculations, the quite different density of states and an unusual enhancement near the Fermi level are observed for NaMn$_6$Bi$_5$, when compared with those of other AMn$_6$Bi$_5$ (A = K, Rb, and Cs) compounds.