Investigation of structural, optical and mechanical behaviour of pure and Cr doped L-asparagine monohydrate single crystals

Pure and Cr doped L-asparagine monohydrate (LAM) single crystals were grown by evaporation controlled solution growth technique. SCXRD, Hirshfeld surface and fingerprint plot were performed for grown crystals. High transmittance, increase in optical bandgap and hardness were observed as result of Cr doping. Therefore, Cr doping makes LAM a better candidate for device fabrication and optoelectonics applications. [Display omitted] •Effect of Cr doping in LAM crystal grown by solution method was investigated.•High transmittance and lower cutoff wavelength were observed in UV–Vis analysis.•Intermolecular interactions were investigated by Hirshfeld surface analysis.•Cr doping has changed the ‘soft’ nature of crystal to ‘hard’ nature.•Pits were created on smooth surface of pure crystal due to Cr addition. Pure and chromium (Cr) doped L-asparagine monohydrate (LAM) single crystals were grown by using evaporation controlled solution growth technique. XRD analysis confirmed the orthorhombic crystal system with space group P212121 of grown crystals. Cr-incorporation decreased the cell parameters and unit cell volume of the crystals. Intermolecular interactions were analysed through Hirshfeld and fingerprint studies. SEM analysis showed the appearance of pits on the smooth surface of pure crystal due to Cr-addition. UV–Vis analysis showed high transparency, low cut-off and direct band gap of 5.42 eV and 5.51 eV for pure and Cr doped crystals, respectively. Fundamental functional groups were identified by FTIR and Raman spectroscopy. The thermal stability and melting point of the crystals were investigated using TGA/DSC analysis. The dielectric constant for doped LAM was increased to 44 as compare to dielectric constant of pure crystal which was 32. Both crystals showed low dielectric loss, having values 0.04 and 0.006 for pure LAM and doped crystals, respectively. In Vickers microhardness test, Cr doping was found to change the nature of pure LAM crystal from ‘soft’ to ‘hard’ as Meyer’s index changed from 2.48 to 1.24.