Positron annihilation exploration of voids in zinc zirconium borate glass ceramics entrenched with ZnZrO 3 perovskite crystal phases

摘要

AbstractOrigin of atomic-deficient free-volume structure in ZnO–ZrO2–B2O3glass ceramic versus ZrO2concentration was explored by positron annihilation lifetime spectroscopy (PAL) technique. XRD and SEM studies, on the titled samples indicated that the samples consist of tetragonal ZnZrO3perovskite crystal phases. The IR spectroscopic studies suggested that Zr4+ions prevailingly occupy octahedral positrons and play crucial role in formation of positron trapping holes in the samples. The PAL studies using 0.1MBq22Na positron source indicated a significant variation in the positron annihilation life time with increasing ZrO2for both positron- and positronium (Ps) trapping channels. The intensity of the longest positron annihilation componentI3is decreased from 4.45 to 3.07%, whereas o-Psdecay lifetimeτ3is enhanced from 1.18 to 1.34ns with increase of ZrO2from 0 to 5.0mol%. These results suggested that the glass ceramic CZ5contains the maximum free space or void expansion and void agglomeration.]]>