Acoustical shock wave induced enhancement of optical transparency in crystalline solid-a case study of p-Nitroaniline

Nitroaniline (PNA) single crystals were grown by the low-temperature solution growth method. Shock waves from a pressure-driven tabletop Reddy tube with an 80 GSM paper diaphragm were utilized to shock the test crystals. A well-polished PNA crystal was subjected to shock pulses ranging from 1 to 5, with a 1.7 Mach number, which corresponds to 1.048 MPa of transient pressure and 644 K of transient temperature. Using a powder X-ray diffractometer, the structural stability of the test crystal against shock waves was examined. Using a UV-Visible spectrometer, the optical transmittance of the PNA crystal under shocked conditions was measured in the 200 nm to 800 nm wavelength range. It is interesting to discover that the shocked crystal exhibits stronger optical transmission than the un-shocked crystal. The transmittance has improved to 46%, which is 33% greater than that of the un-shocked crystal, especially at the fourth shocked condition. Additionally, it is shown that under shocked circumstances, the PNA's absorption edge shifts toward the lower wavelength area, demonstrating that shock waves have enhanced crystallinity. Impedance analysis was used to measure the dielectric in the frequency range of 1 Hz to 1 MHz. It is found that the test crystal's dielectric constant varies depending on the number of shock pulses applied. Compared to an unshocked crystal, the shocked crystal has a higher dielectric constant.