Growth and characterization of bimetallic (Na and K) phthalate single crystals

Bimetallic (Na and K) phthalate single crystals were grown by the solvent evaporation method and characterized. X-ray diffraction (single crystal and powder), Fourier transform infrared spectral and atomic absorption spectral measurements indicate a centrosymmetric trigonal crystal system (space group P\(\bar{3}\)1c) with chemical composition as Na0.51K1.49C8O4H4.H2O. UV–Vis–NIR spectral measurement indicates an optical transmittance of 72 % in the wavelength range 300–1200 nm. The crystal is found to be nonlinear optically active due to local non-centrosymmetry. Thermal and mechanical stabilities of the grown crystal were examined by thermogravimetric and microhardness measurements. Electrical (both AC, with various frequencies ranging from 200 Hz to 200 kHz, and DC) measurements were taken at various temperatures ranging from 30 to 60 °C by the parallel plate capacitor method. The electrical parameters considered are found to increase with the increase in temperature. The AC and DC activation energies were also estimated. The observed high dielectric constants and good second harmonic generation efficiency indicate that the crystal is expected to be useful in capacitor technology and photonic devices.