Synthesis, crystal structure, spectrum properties, and electronic structure of a novel non-centrosymmetric borate, BiCd3(AlO)3(BO3)4

A novel non-centrosymmetric borate, BiCd3(AlO)(3)(BO3)(4), has been prepared by solid state reaction methods below 750 degrees C. Single-crystal XRD analysis showed that it crystallizes in the hexagonal group P6(3) with a=10.3919(15) angstrom, c=5.7215(11) angstrom. Z=2. In its structure, AlO6 octahedra share edges to form 1D (1)(infinity)[AlO4](5-) chains that are bridged by BO3 groups through sharing O atoms to form the 3D (3)(infinity)[AlBO4](2-) framework. The 3D framework affords two kinds of channels that are occupied by Bi3+/Cd2+ atoms only or by Bi3+/Cd2+ atoms together with BO3 groups. The IR spectrum further confirmed the presence of BO3 groups. Second-harmonic-generation measurements displayed a response of about 0.5 x KDP (KH2PO4). UV-vis diffuse reflectance spectrum showed a band gap of about 3.19 eV. Solid-state fluorescence spectrum exhibited the maximum emission peak at around 390.6 nm. Band structure calculations indicated that it is an indirect semiconductor. (C) 2010 Elsevier Inc. All rights reserved.