An investigation of structural parameters and magnetic and optical properties of EuLn2Q4 (Ln=Tb–Lu, Q=S, Se)

EuLn2Q4 (Ln=Tb–Lu; Q=S, Se) has been synthesized using Sb2Q3 (Q=S, Se) fluxes at 1000 °C. These compounds crystallize in a CaFe2O4-type three-dimensional channel structure that is built from edge-shared double rutile chains of [LnQ6] octahedra running down the b-axis. Each double chain is connected at the vertices to four other double chains to form open channels where bicapped trigonal prismatic Eu2+ ions reside. All of these compounds show antiferromagnetic ordering with Neel temperatures, TN∼3–4 K. The optical band gaps for EuTb2Se4, EuDy2Se4, EuHo2Se4, EuEr2Se4, EuTm2Se4, EuYb2Se4 EuLu2Se4, and EuYb2S4 are found to be 2.0, 1.8, 1.8, 1.7, 1.8, 1.3, 1.7, and 1.6 eV, respectively.

Graphical abstractA view of the three-dimensional channel structure of EuYb2S4 down the b-axis.Figure optionsDownload full-size imageDownload as PowerPoint slide