Comparative study on l-alaninium maleate single crystal grown by Sankaranarayanan-Ramasamy (SR) method and conventional slow evaporation solution technique

Single crystals of l-alaninium maleate (LAM) were successfully grown by Sankaranarayanan-Ramasamy (SR) method and conventional slow evaporation solution technique, which have the sizes of 32 mm in length, 18 mm in diameter and 18×13×2 mm3. The grown LAM crystals were subjected to single crystal X-ray diffraction, high resolution X-ray diffraction (HRXRD), chemical etching, dielectric permittivity, dielectric loss, thermo-gravimetric-differential thermal analysis, UV-vis NIR and Vickers microhardness analysis and the results were compared. Single crystal X-ray diffraction confirmed the lattice parameters of the grown LAM crystals. The HRXRD analysis indicated that the crystalline perfection of the SR method grown LAM crystals is quite good without having any internal structural grain boundaries. Chemical etching studies represent the distribution of structural defects in LAM crystal and etch pit density of conventional and SR method grown LAM crystal was calculated. The dielectric permittivity and loss measurement were made as function of temperature in the range 40-140 °C. From thermo-gravimetric-differential thermal analysis of the grown crystal, the thermal stability was found to be up to 158 °C. The range and percentage of optical transmission are represented by recording UV-vis analysis. Mechanical strength of the grown LAM crystals was analyzed by Vickers microhardness test and the hardness of SR method grown LAM crystal is higher than the hardness of the crystal grown by conventional method.