We report the synthesis, structural and physical properties of a new layered transition metal arsenide Na₄Cu₃TaAs₄. This material adopts the space group I4̄2m, with lattice parameters of a=5.9101(3) Å and c=13.8867(12) Å. This structure contains two layers of Na sandwiched by anti-PbO-type (Cu/Ta)As layers, similar to the “111”-type iron-based superconductor NaFeAs. The transition metal sites are occupied by 75% Cu and 25% Ta, with Ta forming a well-defined \(\sqrt 2 \times \sqrt 2 \times 2\) superstructure. Cu and Ta were determined to be +1 and +5 oxidation state respectively. The band structure of the Na₄Cu₃TaAs₄ measured by angle resolved photoemission spectroscopy (ARPES) is in good agreement with the density functional theory (DFT) calculation. Both ARPES and resistivity measurement indicate that this material exhibits metallic behavior with p-type carriers. Magnetic susceptibility measurement shows that the material exhibits nearly T-independent diamagnetism. This new material extends the material system with anti-PbO-type layers and offers a good playground to investigate this material system further.

我们报告了新的层状过渡金属砷化物Na ₄ Cu ₃ TaAs ₄的合成，结构和物理性质。该材料采用空间组I4̄2m，其晶格参数为a = 5.9101（3）Å和c = 13.8867（12）Å。该结构包含两层Na，这些Na夹在抗PbO型（Cu / Ta）As层之间，类似于“ 111”型铁基超导体NaFeAs。过渡金属位点被75％的Cu和25％的Ta占据，Ta形成了明确的\（\ sqrt 2 \ times \ sqrt 2 \ times 2 \）上层结构。Cu和Ta分别被确定为+1和+5氧化态。Na ₄ Cu ₃的能带结构通过角分辨光发射光谱法（ARPES）测量的TaAs ₄与密度泛函理论（DFT）的计算非常吻合。ARPES和电阻率测量均表明该材料在p型载流子方面表现出金属性能。磁化率测量表明该材料表现出几乎不依赖T的反磁性。这种新材料扩展了具有抗PbO型层的材料系统，并为进一步研究该材料系统提供了一个很好的场所。