Crystal chemistry, second-order nonlinear optical, and magnetic properties of Eu8Sn4Se20

Second-order nonlinear optical (NLO) materials in the middle infrared (MIR) region have attracted widespread interest in view of their importance and deficiency to the laser market’s requirement. Here, we report a new MIR NLO material Eu 8 Sn 4 Se 20 ( 1 ), which represents a new structure type one and the pioneer of the (M II 2 M IV Q 5 ) n (M II  ​= ​divalent alkali-earth metal, Eu, Yb, Pb, and Sn; M IV  ​= ​Si, Ge, Sn; Q ​= ​S, Se, Te. n  ​= ​1, 2, 4) family. It demonstrates obvious second-harmonic generation (SHG) activity. Its optical band gap is determined to be 1.30 ​eV and its magnetic data exhibits antiferromagnetic-type behavior. Its electronic structure is performed as well.