Single crystal growth and characterization of R₂Co₆Al_20-_δ(R = Gd-Tm,Y)

We report the single crystal growth and characterization of the ternary rare-earth based aluminides R₂Co₆Al_20-δ (R = Gd-Tm,Y). Although earlier reports proposed a monoclinic C2/m (#12) phase with composition R₂Co₆Al₁₉ [1], our single crystal X-ray diffraction results reveal that these materials adopt an orthorhombic Imma structure, with δ varying non-monotonically across the heavy rare earths (δ ≈ 0.73–0.91). In addition to structural characterization, we provide a detailed overview of the anisotropic magnetic, transport and specific heat across the series. All compounds exhibit antiferromagnetic ordering at low temperatures (ranging from 1.8K-11.8K).

 

[1] A.V. Morozkin et al., Journal of Solid-State Chemistry 62-74, 261 (2018)