diammonium fumarate

Characterization of Diammonium Fumarate Third-Order Nonlinear Optical Crystals

Kalaimani, N., et al. Chinese Journal of Physics, 2019, 61, 104-112.

The crystals of diammonium fumarate were precipitated from aqueous solution by slow evaporation and the structural, optical, spectral and thermal parameters determined by a suite of characterization procedures.
· Growth of Diammonium Fumarate Crystals
Diammonium fumarate crystals were obtained using a slow evaporation technique. The solution was made using ammonium carbonate and fumaric acid in 1:1 molar quantities in double-distilled water. The solution was stirred for three hours with a magnetic stirrer until a uniform saturated solution was formed. This watery solution was passed through Whatmann filter paper. Following filtration, the solution was covered with polythene paper, with several holes made to allow for solvent evaporation.
· Properties of Diammonium Fumarate
Single crystal X-ray diffraction analysis was conducted to determine the lattice parameters, confirming that the crystal system is monoclinic. A lower cutoff wavelength was observed at 300 nm. The molecular structure of the grown crystal was elucidated by 1H and 13C NMR spectroscopy. Thermal behavior was assessed using TG/DTA experiments, indicating that the crystal remains thermally stable up to 225 °C. Additionally, parameters such as χ3 = 9.33 × 10-6 esu and n2 = -10.31 × 10-8 cm2/W were computed using the Z-scan technique, demonstrating that the crystal is suitable for third harmonic generation.