Na3Cd3B(PO4)4: A New Noncentrosymmetric Borophosphate with Zero-Dimensional Anion Units

A new noncentrosymmetric borophosphate, Na3Cd3B­(PO4)4, has been successfully synthesized by conventional solid state reaction for the first time. It crystallizes in the orthorhombic space group Pmc21 with unit cell parameters of a = 13.6854(3) Å, b = 5.3346(11) Å, c = 18.2169(4) Å, and Z = 4. Na3Cd3B­(PO4)4 features zero-dimensional [B­(PO4)4]9– anion units with Cd2+ and Na+/Cd2+ cations located around them, in which the BO4 tetrahedron is surrounded by four PO4 tetrahedra by sharing the vertexes of O atoms. Second harmonic generation (SHG) measurements show that Na3Cd3B­(PO4)4 exhibits a SHG response 1.1 times larger than that of KH2PO4 (KDP) and is phase matchable.