Bi32Cd3P10O76: a new congruently melting nonlinear optical crystal with a large SHG response and a wide transparent region

Exploring new nonlinear optical (NLO) crystals with large second harmonic generation (SHG) responses and easy crystal growth is urgent and a considerable challenge. By combining the Bi3+ cation with stereochemically active lone pairs and the d10 Cd2+ cation, a new noncentrosymmetric and polar metal phosphate, Bi32Cd3P10O76 (BCPO), has been successfully synthesized. It exhibits a large SHG response (∼4 × KDP) and a wide transmission range (0.36–4.9 μm). What's more, this compound melts congruently. We have grown its high-quality single crystals with sizes up to 19 × 13 × 6 mm3. These results indicate that BCPO will be a potential NLO material, especially for application in the 3–5 μm range. Further, its structure–property relationship has also been studied based on dipole moment calculation.