Second-harmonic generation effect enhanced by Li substitution for Na in Li1(LiXNa5−X)Mo9O30

Large single crystals of the solid-solution series were grown by the Czochralski method by varying the Li substitution for Na. Structure analyses with X-ray single-crystal diffraction data elucidated statistic disorder of Li with Na at three independent Na sites. The resulting Li substitution X = 0, 1.2, and 2.8 could be confirmed by neutron activation analysis. Second-harmonic generation (SHG) light intensities and non-linear optical (NLO) coefficients were determined in three crystallographic main directions by Maker fringe measurements. DFT calculations delivered absolute NLO magnitudes. UV/Vis optical spectra revealed that the transmission rises from X = 0 to X = 2.8. However, the SHG effect is at largest in (X = 1.2), so far investigated in this study.