A new congruent-melting oxyborate, Pb₄O(BO₃)₂with optimally aligned BO₃triangles adopting layered-type arrangement

Abstract

Introduction of the stereo-effect of the lone pair of the Pb2+ cation in borate with layered-type arrangement of BO3 triangles generates a new phase-matching nonlinear optical material, Pb4O(BO3)2. In the structure, the interesting Pb4O10 tetramers are connected to each other by sharing O atoms to form a 3D framework. In the space of the framework, the isolated BO3 and B2O5 groups are arranged parallel to the (100) to balance charge. The title compound melts congruently and exhibits a SHG response of ∼3 times that of KDP and ∼160 times that of a-SiO2. And it has a wide transparent region from the UV to near IR region with a UV cut-off edge of 280 nm, which means that Pb4O(BO3)2 is a very promising NLO material for potential application.