Single crystal growth of 4-aminobenzophenone (ABP) by micro-capillary Czochralski melt technique for second harmonic generation (SHG) applications

Abstract

Single crystal of 4-aminobenzophenone (ABP) was grown by micro-capillary Czochralski (mc-CzT) pulling technique from melt using a laboratory designed mini-Czochralski crystal puller set-up with its seed-rod attached with micro-capillary tube. The capillary action of the melt at the tip of the micro tube was carefully controlled in such a way that a single crystal nucleation was induced at the melt interface. Optimization of the melt temperature along with successive control of the rotation and upward pulling rates of the micro-capillary tube led to a successful single crystal growth of ABP. Crystal structure of the grown ABP was confirmed by single crystal X-ray diffraction (SCXRD) structural refinement and the molecular packing stability in the unit cell was studied through intermolecular hydrogen bonding interactions via theoretical means. Further, powder X-ray diffraction (PXRD), UV–visible-near IR (UV–vis-NIR), Fourier-transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) analyses were carried out to confirm the crystalline purity, optical transparency, modes of molecular vibrations and thermal stability of the grown crystal. Kurtz and Perry technique was used to study second harmonic generation (SHG) ability of the grown ABP crystal and found that the SHG efficiency was about 15 times that of potassium dihydrogen phosphate (KDP) and 5 times that of urea.