| Abstract: | An ammonium‐containing metal iodate fluoride compound, (NH4)Bi2(IO3)2F5, featuring a two‐dimensional double‐layered framework constructed by BiO2F5]6? and BiO4F4]9? polyhedra, as well as IO3]? groups, was successfully synthesized. The well‐ordered alignment of these SHG‐active units leads to an extraordinary strong SHG response of 9.2 times that of KDP. Moreover, this compound possesses a large birefringence (Δn=0.0690 at 589.3 nm), a wide energy band gap (Eg=3.88 eV), and a high laser damage threshold (LDT; 40.2×AgGaS2). In particular, thermochromic behavior was observed for the first time in this type of compound. Such multifunctional crystals will expand the application of nonlinear optical materials. |
