Na₂Mg1−xZnxSiO₄ (0 ≤ x ≤ 1): Noncentrosymmetric Sodium Metal Silicate Solid Solutions with Ultraviolet Nonlinear Optical Properties

Stoichiometrically equivalent noncentrosymmetric (NCS) sodium metal silicates, Na 2 MgSiO 4 and Na 2 ZnSiO 4 , and their solid solutions have been synthesized via solid‐state reactions. The structures of the reported materials were determined by powder X‐ray diffraction using the Rietveld method. A careful structural analysis indicates that the unit cell volumes of Na 2 Mg 1− x Zn x SiO 4 solid solutions decrease as more Zn 2+ cations are doped into the site of Mg 2+ . Also, the synthesized silicate solid solutions revealed three‐dimensional frameworks consisting of highly distorted yet well‐aligned MgO 4 (or ZnO 4 ) and SiO 4 tetrahedra. The title compounds exhibit very large band gaps ranging from 5.57 to 6.05 eV. Second‐harmonic generation (SHG) measurements indicate that the solid solutions are phase‐matchable and the SHG efficiencies increase as more d 10 cation, Zn 2+ , is added to the backbone. A complete characterization is presented along with the explanation of the structure‐SHG property relationship.