Two Noncentrosymmetric Bismuth Phosphates: Rational Design Synthesis and Optical Properties.

Developing strategies to rational design noncentrosymmetric structure still attract much interest for their applications in nonlinear optical and piezoelectric materials. Two noncentrosymmetric (NCS) alkaline earth metal bismuth phosphates have been successfully achieved via partial replacement of Bi 3+ with Ca 2+ or Sr 2+ ions. BiCa(H 0.5 PO 4 ) 2 (designated as CaBiPO) and BiSr(H 0.5 PO 4 ) 2 (designated as SrBiPO), together with their solid solution Bi(Sr 1- x Ca x )(H 0.5 PO 4 ) 2 (0 < x ≤ 0.5), crystallize in the NCS space group C 2. Both CaBiPO and SrBiPO exhibit ultraviolet nonlinear optical (NLO) properties, and their second-harmonic generation effects belong to type-II phase matching. Meanwhile, they could also act as photoluminescence hosts in which the Eu 3+ -doping samples SrBiPO: x Eu 3+ ( x = 0.02-0.2) emit orange light. The effect of different radius ions on the derivative structures and the structure-NLO property relationship has also been discussed in detail.