BaSc2(HPO3)4(H2O)2: a new nonlinear optical phosphite exhibiting a 3D {[Sc2(HPO3)4]2−}∞ anionic framework and phase-matchable SHG effect

Abstract

Phosphite materials have aroused wide attention due to their diverse open frameworks and promising magnetic and optical performances. Here, the first barium scandium phosphite, BaSc₂(HPO₃)₄(H₂O)₂, was obtained via a facile hydrothermal route. BaSc₂(HPO₃)₄(H₂O)₂ crystallizes in the polar space group Pn and exhibits a 3D {[Sc₂(HPO₃)₄]²⁻}_∞ anion framework constructed by distorted ScO₆ octahedra and HPO₃²⁻ anion groups. BaSc₂(HPO₃)₄(H₂O)₂ can exhibit a phase-matchable SHG response of about 0.94 × KH₂PO₄ at 1064 nm, and a moderate birefringence (0.036@1064 nm) to satisfy the phase-matchable behavior requirement. Deep investigation of its structure–property relationship based on theoretical calculations has also been presented in this work.