A Facile Route to Nonlinear Optical Materials: Three‐Site Aliovalent Substitution Involving One Cation and Two Anions

Two mixed‐metal gallium iodate fluorides, namely, α‐ and β‐Ba 2 [GaF 4 (IO 3 ) 2 ](IO 3 ) ( 1 and 2 ), have been designed by the aliovalent substitutions of α‐ and β‐Ba 2 [VO 2 F 2 (IO 3 ) 2 ](IO 3 ) ( 3 and 4 ) involving one cationic and two anionic sites. Both 1 and 2 display large second‐harmonic generation responses (≈6×KH 2 PO 4 (KDP)), large energy band gaps (4.61 and 4.35 eV), wide transmittance ranges (≈0.27–12.5 μm), and high relevant laser‐induced damage thresholds (29.7× and 28.3×AgGaS 2 , respectively), which indicates that 1 and 2 are potential second‐order nonlinear optical materials in the ultraviolet to mid‐infrared. Our studies propose that three‐site aliovalent substitution is a facile route for the discovery of good NLO materials.