Quasi-one-dimensional materials exhibit not only unique crystal structure but also abundant physical properties such as charge density wave, Luttinger liquid, and superconductivity. Here we report the discovery, structure, and physical properties of a new manganese-based quasi-one-dimensional material RbMn6Bi5, which crystallizes in a monoclinic space group C2/m (No. 12) with lattice parameters a = 23.286(5) Å, b = 4.6215(9) Å, c = 13.631(3) Å, and β = 125.00(3)°. The structure features [Mn6Bi5]−1 double-walled column extending along the [010] direction, together with Bi–Bi homoatomic bonds linking the columns and the countercation Rb+. The temperature-dependent resistivity clearly indicates a significant resistivity anisotropy for RbMn6Bi5, whereas the magnetic susceptibility and specific heat measurements show that RbMn6Bi5 is antiferromagnetic below 82 K. The density functional theory calculations indicate that RbMn6Bi5 is a quasi-one-dimensional metal with possible helical antiferromagnetic configuration. The discovery of RbMn6Bi5 confirms the viability of discovering new quasi-one-dimensional materials in manganese-based compounds.

The electride materials with free-electron gas have attracted intensive attention both experimentally and theoretically. Here, we demonstrate the effective modulation of the electronic and magnetic properties of monolayer electride Ca 2 N by hydrogenation based on first-principles calculations. The adsorption of hydrogen atoms can drive the pristine monolayer Ca 2 N from a nonmagnetic (NM) metal to a NM semiconductor in the semihydrogenation condition (one-sided coverage) and further to a ferromagnetic half-metal in the fully hydrogenation condition (two-sided coverage). In the former case, the free-electron gas on both sides of the monolayer Ca 2 N disappears, resulting in a semiconducting phase with a modest band gap of 1.13 eV. In the latter case, there is a structural phase transition from the 1 × 1 periodicity to the 3 × 3 one because of Fermi surface nesting; meanwhile, the magnetic moment of 1.0 μ B per unit cell is induced by the p orbitals of N atoms. With these flexible properties, the hydrogenated monolayer electride Ca 2 N has promising potential applications in future electronic and spintronic devices.

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Kagome materials have been reported to possess abundant and peculiar physical properties, which provide an excellent platform to explore exotic quantum states. We present a discovery of superconductivity in van der Waals material Pd3P2S8 composed of Pd kagome lattice under pressure. Pd3P2S8 displays superconductivity for those pressures where the semiconducting-like temperature dependence of the resistivity turns into a metallic one. Moreover, it is found that the increased pressure results in a gradual enhancement of superconducting transition temperature, which finally reaches 6.83 K at 79.5 GPa. Combining high-pressure x-ray diffraction (XRD), Raman spectroscopy and theoretical calculations, our results demonstrate that the observed superconductivity induced by high pressure in Pd3P2S8 is closely related to the formation of amorphous phase, which results from the structural instability due to the enhanced coupling between interlayer Pd and S atoms upon compression.

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