LiMg(IO(3))(3): an excellent SHG material designed by single-site aliovalent substitution

An excellent second harmonic generation (SHG) material, LiMg(IO(3))(3) (LMIO), has been elaborately designed from Li(2)M(IV)(IO(3))(6) (M(IV) = Ti, Sn, and Ge) by aliovalent substitution of the central M(IV) cation followed by Wyckoff position exchange. The new structure sustains the ideal-alignment of (IO(3))(–) groups. Importantly, LMIO exhibits an extremely strong SHG effect of roughly 24 × KH(2)PO(4) (KDP) under 1064 nm laser radiation or 1.5 × AgGaS(2) (AGS) under 2.05 μm laser radiation, which is larger than that of α-LiIO(3) (18 × KDP). The replacement of M(IV) with Mg(2+) without d–d electronic transitions induces an obviously larger band gap (4.34 eV) with a short absorption edge (285 nm). This study shows that single-site aliovalent substitution provides a new synthetic route for designing SHG materials.