BaClBF4: a new noncentrosymmetric pseudo-Aurivillius type material with transparency range from deep UV to middle IR and a high laser damage threshold

A new noncentrosymmetric alkaline earth metal halide borate, BaClBF4, has been synthesized with crystal size up to 6 mm x 6 mm x 3 mm via the hydrothermal method at 200 degrees C. The crystal structure can be described as an alternate stacking of cationic [Ba2Cl2](2+) layers with anionic [BF4](-) layers along the b direction, and the [Ba2Cl2](2+) layer is a pseudo-Aurivillius type layer similar to the [Bi2O2](2+) layer. The transmittance range of BaClBF4 is from 0.18 to 8.5 mu m, and the laser damage threshold of the crystal is about 6.8 GW cm(-2). EDS, TG-DSC and second harmonic generation investigations are reported. The electronic structure is discussed to explain the structure-property relationships.