BiSr3(YO)3(BO3)4: A New Gaudefroyite-Type Rare-Earth Borate with Moderate SHG Response

The synthesis, crystal structure, crystal growth, and characterization of a new noncentrosymmetric rare-earth borate BiSr3(YO)3(BO3)4 are reported. BiSr3(YO)3(BO3)4 belongs to gaudefroyite type of structure and crystallizes in the polar hexagonal space group P63 (no. 173) with a = 10.6975(16) Å and c = 6.7222(12) Å. In the structure, the YO7 polyhedra share edges to form an one-dimensional chain along the [001] direction. These chains are interconnected by the BO3 group to construct a three-dimensional framework, leaving two kinds of channels for Bi atoms and Sr atoms together with BO3 groups, respectively. On the basis of the powder second-harmonic generation (SHG) measurement, BiSr3(YO)3(BO3)4 belongs to the phase-matchable class with a SHG response of about 3 × KDP.