Influence of dye doping on the structural, spectral, optical, thermal, electrical, mechanical and nonlinear optical properties of L-histidine hydrofluoride dihydrate crystals

Abstract

Structural, optical, NLO and other properties of Rhodamine-B (dye) doped L-histidine hydrofluoride dihydrate (RLHHF) crystals have been investigated in this work. RLHHF crystals were grown by the slow evaporation technique at room temperature. The results of single X-ray diffraction reveal the orthorhombic system of RLHHF crystal with a non-centrosymmetric space group P21 21 21. Various diffracting planes of the grown crystal were identified from the powder X-ray diffraction study. Fourier transform infrared spectral analysis was used to identify the functional groups present in the crystal. The optical transmittance spectrum was recorded for powder RLHHF sample and the transmittance observed is about 85% in visible region with a lower cut-off wavelength at 237 nm. The fluorescence emission spectrum shows the emission is in the yellow region. The presence of various elements in the crystal was analyzed using EDAX technique. Mechanical hardness, stiffness constant, and yield strength were estimated by the Vickers microhardness technique. Thermal studies were carried out to discuss the thermal stability and various decomposition stages of the material. The dielectric constant, dielectric loss and AC conductivity of the title material were calculated at different temperatures and frequencies to analyze the electrical properties. By Kurtz-Perry technique, SHG measurement was carried out and it is observed that the SHG efficiency of the powdered RLHHF sample increases as the particle size increases.