浙江大学曹光旱团队报道了Th₂Cu₄As₅中超导性和电荷密度波状跃迁。相关研究成果于2024年3月18日发表在《美国化学会杂志》。

研究人员报道了一种新的三元化合物Th₂Cu₄As₅的合成、晶体结构和物理性质。该材料结晶为四方结构，晶格参数a=4.0639（3）和c=24.8221（17）。其结构可以描述为萤石型Th₂As₂层与反萤石型双层Cu₄As₃板的交替堆叠。电阻率、磁化率和比热的测量表明，Th₂Cu₄As₅在4.2K时经历体超导转变。

此外，所有这些物理量在48K时都表现出异常，并伴随着霍尔系数的符号变化，这表明存在电荷密度波状（CDW）相变。根据实验数据和能带计算，研究人员认为超导和类CDW相变分别与Th₂As₂层中的Cu₄As₃板和As平面有关。

附：英文原文

Title: Superconductivity and Charge-Density-Wave-Like Transition in Th2Cu4As5

Author: Shaohua Liu, Qingchen Duan, Baizhuo Li, Jiaojiao Meng, Wuzhang Yang, Yi Liu, Yi-Qiang Lin, Si-Qi Wu, Jiayi Lu, Jin-Ke Bao, Yusen Xiao, Xinyu Zhao, Yu-Xue Mei, Yuping Sun, Shugang Tan, Qiang Jing, Dan Yu, Ruidan Zhong, Yongliang Chen, Yong Zhao, Zhi Ren, Cao Wang, Guang-Han Cao

Issue&Volume: March 18, 2024

Abstract: We report the synthesis, crystal structure, and physical properties of a novel ternary compound, Th2Cu4As5. The material crystallizes in a tetragonal structure with lattice parameters a = 4.0639(3) and c = 24.8221(17) . Its structure can be described as an alternating stacking of fluorite-type Th2As2 layers with antifluorite-type double-layered Cu4As3 slabs. The measurement of electrical resistivity, magnetic susceptibility, and specific heat reveals that Th2Cu4As5 undergoes bulk superconducting transition at 4.2 K. Additionally, all these physical quantities exhibit anomalies at 48 K, accompanied by a sign change in the Hall coefficient, suggesting a charge-density-wave-like (CDW) phase transition. Drawing from both experimental data and band calculations, we propose that the superconducting and CDW-like phase transitions are, respectively, associated with the Cu4As3 slabs and the As plane in the Th2As2 layers.

DOI: 10.1021/jacs.3c13257

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.3c13257