Lanthanide thioborates, an emerging class of nonlinear optical materials, efficiently synthesized using the boron-chalcogen mixture method.

The Boron-Chalcogen Mixture method was used to obtain single crystals of the previously extremely difficult to synthesize lanthanide orthothioborates to investigate their structures and their structurally connected optical behavior, such as second harmonic generation. Using a combined halide and polychalcogenide flux, the BCM method yielded single crystals of LnBS (Ln = La, Ce, Pr, Nd), which are isostructural and crystallize in the non-centrosymmetric space group, 2. Second harmonic generation measurements confirmed the expectation that LaBS would exhibit a strong SHG response, measured at 1.5 × KDP.