M. Jose

Optical and spectroscopic studies of potassium p-nitrophenolate dihydrate crystal for frequency doubling applications

Non centrosymmetric potassium p-nitrophenolate dihydrate single crystals have been grown by employing the technique of slow solvent evaporation from aqueous solution by slightly adjusting the pH and growth temperature. The grown crystals have been identified from single crystal XRD analysis, FTIR and FT Raman spectroscopic techniques. The high resolution X-ray diffraction experiments substantiate good quality of the title material. Between 510 and 2000 nm, the material is observed to be nearly transparent allowing it to be explored for potential use in device fabrication. In addition, the photoluminescence spectrum of the grown crystal at room temperature shows a stable broad violet-blue emission around the 383-550 nm wavelengths with the maximum centered at 436 nm. Owing to its excellent non linear figure of merit and strong PL emission, the title crystal can have technological applications in opto-electronic devices.

Ferroelectric Behavior of Organic Terahertz Radiating DAST Crystal

Bulk terahertz emitting and technologically advanced DAST crystal is grown using a simple, cost effective and efficient seed rotation technique from a saturated methanol solution. The grown crystal is identified by a single crystal XRD analysis and powder X-ray diffraction studies. HRXRD experiments substantiate a good crystalline perfection without interior grain boundaries. The ferroelectric nature of the crystal has been described by P–E hysteresis loop analysis, which corroborates with better ferroelectric behavior than other benchmarked inorganic materials. The hardness, elastic stiffness, and yield strength shows decreasing trend for increasing loads and the work hardening coefficient confirm that the DAST is a soft material. Two-dimensional nucleation growth with minimum dislocation is evident from the etch patterns.