ChemInform Abstract: Experimental and Theoretical Studies on the Crystal Structure of Ternary Copper Arsenides A2Cu3As3(A: Sr, Eu)

Two new ternary copper-containing arsenides, Sr2Cu3As3 and Eu2Cu3As3, were synthesized through Pb-flux reactions. In combination with theoretical calculations, the crystal structures of these compounds were determined through single-crystal X-ray diffraction. Both compounds crystallize in the orthorhombic space group Cmcm (no.63) with the cell parameters a = 4.2465(6)/4.1866(5) A, b = 17.604(3)/17.486(2) A, and c = 4.2552(6)/4.2096(5) A for the Sr- and Eu-containing compounds, respectively. Temperature-dependent magnetic susceptibility measurements suggest that both ferromagnetic and antiferromagnetic coupling exists in the structure of Eu2Cu3As3 for the Eu 4f states. According to DFT calculations, these compounds are metallic, and the Cu 3d orbitals make significant contributions to the states around the Fermi level.