A new metal-organic hybrid crystal with excellent transparency in the visible spectrum: Growth, structure and properties of sodium fumarate – Boric acid tetrahydrate

Abstract

Single crystals of sodium fumarate-boric acid tetrahydrate (SBF) were grown by a slow evaporation solution technique. The crystal belongs to orthorhombic lattice system. Identification of the functional groups and the nature of bonding involved in this crystal were elucidated by FTIR. The crystal is transparent in the entire visible region with a lower cutoff around 384 nm and the band gap of 5.5 eV. The photoactive material can have the ability to emit fluorescent radiation in the wavelength range of 490 nm. The hydrated crystal is thermally stable; in the receipt of dehydration it loses its stability. The mechanically soft natured crystal obeys the reverse indentation size effect for the applied loads. The elevated dielectric constant and dielectric loss are assisted by the hydrated water and it diminished as the material dehydrates at higher temperature. The slower motion of the dipole induces frequency of the applied field and hence the impedance decreases with increasing frequency.