Sn2Ga2S5: A Type of IR Nonlinear-Optical Material.

The deficiency of nonlinear-optical (NLO) materials in the IR region inspires strong research interest in this field. Here, Sn2Ga2S5 (1), crystallizing in the orthorhombic Pna21 space group, demonstrates obvious NLO activity, around a maximum of 1.6 times that of AgGaS2 and a strong laser-induced damage threshold of 9.7 times that of AGS. 1 represents the first NLO-active compound in the MII2MIII2Q5 (MII = divalent Ca, Sr, Ba, Pb, Sn, and Eu; MIII = B, Al, Ga, and In; Q = S and Se) family. The NLO performances of 1 are systematically studied experimentally and theoretically.