Unidirectional growth, improved structural perfection and physical properties of a semi-organic nonlinear optical dichlorobis(L-proline)zinc(II) single crystal

A single crystal of dichlorobis(L-proline)zinc(II) (LPZ) was successfully grown by the Sankaranarayanan-Ramasamy (SR) method and conventional slow evaporation solution technique (SEST). The lattice parameters of the grown LPZ crystal were confirmed by single crystal X-ray diffraction. The morphology of the conventional method grown LPZ crystal was identified. HRXRD analysis indicates that the crystalline perfections of the grown crystals are excellent without having any low angle internal structural grain boundaries. Etch pit density of the conventional and SR method grown LPZ crystals were calculated. Piezoelectric d33 coefficient of the SR method grown crystal were higher than the conventional method grown LPZ crystal. The dielectric constant and loss measurements were made as a function of temperature in the range between 40 °C and 140 °C. A low value of dielectric loss was observed in the SR method grown crystal. The obtained transparency for the crystals grown by the SR and conventional methods are 71% and 60%, respectively in the entire visible region. Microhardness measurements revealed the mechanical strength of the grown crystal. Second harmonic generation (SHG) measurement indicates that the SHG efficiency of the grown LPZ crystal was equal to that of KDP crystals.

► Large size and high quality LPZ crystal were grown by SR method.
► Properties of the grown LPZ crystal were studied.
► The SR grown crystal has excellent crystalline perfection.