کوروش قیصری

Cerium-doped sodium chloride micro and nanoparticles were synthesized without (sample a) and with (sample b) applying 20 kHz ultrasonic waves. Particles size and shape were identified by scanning electron microscopy and X-ray diffraction pattern. Using the Williamson Hall equation, the approximate sizes of ~462 nm and 45 nm were obtained for samples (a) and (b), respectively. Thermoluminescence glow curve as well as photoluminescence spectra of the both samples were also investigated. The results show that nanoparticles made in presence of ultrasonic waves have a smaller size and more homogeneous structure than those made in absence of ultrasonic waves. Photoluminescence emission of sample (a) and (b) correspondingly at 383 nm and 370 nm is related to the electron transfer from the 5d→4f bands. Furthermore, both samples are sensitive to gamma rays at high doses. The Thermoluminescence sensitivity of sample (a) is about six times more than that of sample (b) which confirms the dependence of Thermoluminescence sensitivity on the particle size. Fading of sample (b) within one month is about two times more than other of interest.