Introduction of Diverse Divalent Main-Group Metal Cations to Tune the Physical Properties of Rare-Earth Thiophosphates.

Metal chalcophosphates have extensive applications in numerous frontier scientific fields due to their rich structures. Herein, six novel quaternary thiophosphates (MEu)PS (M = Ca, Sr, Ba, and Pb), viz. (CaEu)PS (), (SrEu)PS (), (BaEu)PS (), (PbEu)PS (), (BaEu)PS (), and (BaEu)PS (), were synthesized by the flux-assisted boron-sulfur solid-state reactions. They crystallize in the monoclinic 2/ space group, and their three-dimensional polyanionic frameworks are constructed by M/EuS polyhedra and PS dimers. The crystal chemistry of - is systematically analyzed, and the effects of cation partial substitution and co-occupation on the local structure and electronic structure are studied. The optical band gaps and birefringences of - are in the ranges of 2.04 ∼ 2.64 eV and 0.06 ∼ 0.09, respectively, and they exhibit ferromagnetism or antiferromagnetism. shows a significant photocurrent response (56.43 μA/cm). This work enriches the chemistry of rare-earth chalcophosphates and gives some hint for their further development.