Hydrogen trapping and luminescence characteristic in ion-implanted Li 2TiO 3 and Li 2ZrO 3

Abstract

Hydrogen trapping and its interaction with defects in Li 2TiO 3 and Li 2ZrO 3 that were irradiated with hydrogen isotopes and exposed to air were investigated using ion beam techniques and photo-stimulated luminescence (PSL) measurements. During irradiation with 10 keV H 2 +, the incident hydrogen was trapped in Li 2TiO 3 at the end of its trajectory until the local concentration reached 12.5 at.%, whereas an increase in the hydrogen retained in Li 2ZrO 3 was observed at a considerably greater depth as compared to the projected range. A broad PSL emission with two peaks at around 2.8 and 3.1 eV was observed under irradiation of Li 2ZrO 3 with 5.17 eV light. The PSL intensity of the band at 2.8 eV showed a remarkable decrease as compared to the peak at 3.1 eV upon irradiation with 10 keV D 2 +. The results of isochronal annealing subsequent to irradiation showed that the recovery of the luminescence intensity in the 2.8 eV luminescent centers and release of hydrogen occurred in the same temperature range of 350–450 K. In addition, the formation of a Li 2CO 3 layer at the surface of Li 2TiO 3 and Li 2ZrO 3 following exposure to air was subject to the humidity conditions and was considered to play an important role in the dissociation of water vapor and hydrogen trapping beneath the reaction layer in Li 2TiO 3 and Li 2ZrO 3.