BaBiBO_4, a novel non-centrosymmetric borate oxide

摘要

BaBiBO_4, or BaBi(BO_3)O, is a novel borate oxide which has been synthesized by solid-state reaction at temperatures below 650 deg C and 1 atm pressure. Its crystal structure has been determined from powder X-ray diffraction data and refined from powder neutron diffraction data (non-centrosymmetric Pna2_1 space group, a = 8.5817(7), b = 9.6802(7), c = 5.1505(4) A, Z = 4). The structure is built of [001] chains of edge-sharing BO_3 and BiO_5 groups interleaved with Ba~(2+) cations. The measurement of the nonlinear optical properties of a powder sample by the Kurtz-Perry method yielded an efficiency for second-harmonic generation equal to five times that of KH_2PO_4.