Synthesis, crystal structure and physical properties of quasi-one-dimensional ACr_3As_3(A = Rb, Cs)

准一维ACr_3As_3(A=Rb,Cs)的合成、晶体结构与物理性质（英文）

Recently, new Cr-based superconductors, A2Cr3As3(A = K, Rb, Cs), have gained intense interest because of their one-dimensional crystal structures and electron correlations. Here we report the crystal structure and physical properties of two related materials ACr3As3(A = Rb, Cs) which are synthesized via a soft-chemical A+ deintercalation in A2Cr3As3. The new compounds remain one-dimensional(Cr3As3)∞ linear chains, and the interchain distance can be tuned by the incorporation of the alkali-metal cations with different sizes. The physical property measurements indicate a local-moment behavior at high temperatures, and the moments freeze into a cluster spin-glass state below 5–6 K. No superconductivity was observed in both materials. We also found that, with increasing the interchain distance, the Cr effective moments increase monotonically, accompanied with the enhancement of semi-conductivity. Our results shed light on the understanding of occurrence of superconductivity in A2Cr3As3.

最近,新铬基超导体A2Cr3As3(A=K,Rb,Cs)因其准一维结构以及电子关联效应而引起同行的强烈兴趣.本文报道了两种相关材料(Rb Cr3As3和Cs Cr3As3)的晶体结构与物理性质.该新材料是从A2Cr3As3中通过软化学反应而获得.它们保持一维(Cr3As3)∞线状长链,其链间距可以通过引入不同尺寸的碱金属阳离子进行调节.物理性质测量表明,样品在高温区具有局域磁矩行为,而在5~6K以下形成团簇自旋玻璃态.未观察到任何超导电性.我们还发现,样品的有效磁矩随链间距的增加而单调增加,同时伴随半导体导电特征的增强.上述实验结果可能为理解A2Cr3As3系统中的超导电性提供有价值的线索.