CeAgAs 2 — a New Derivative of the HfCuSi 2 Type of Structure: Synthesis, Crystal Structure and Magnetic Properties

Single crystals of CeAgAs 2 have been obtained by chemical transport reactions starting from a pre‐reacted powder sample. The crystal structure was solved using X‐ray diffraction (space group Pmca , No. 57, a = 5.7586(4) Å, b = 5.7852(4) Å, c = 21.066(3) Å, Z = 8) and refined to a residual of R(F) = 0.029 for 46 refined parameters and 1020 reflections. The structure of CeAgAs 2 represents a new distorted and ordered variant of the HfCuSi 2 type. The characteristic feature of this structure are infinite cis‐trans chains of As atoms with As—As distances of 2.563(1) Å and 2.601(1) Å. CeAgAs 2 is paramagnetic ( μ eff = 2.37 μ B , θ = —10.5(2) K), with antiferromagnetic ordering at 5.5(2) K and exhibits a metamagnetic transition starting at 4.6 kOe and T = 1.8 K.