Effect of annealing on luminescence of ZrO2 irradiated with 100 MeV Si7+ ions

Abstract

Zirconium oxide (ZrO2) sample was synthesized by the solution combustion technique and annealed at different temperatures. Effect of thermal annealing on structure, band gap, photoluminescence (PL), thermoluminescence (TL) response and kinetic parameters of 100 MeV Si7+ ion irradiated ZrO2 have been investigated. Powder x-ray diffraction (XRD) pattern of the samples reveal the monoclinic phase. Field emission scanning electron microscopy (FESEM) shows that the grains are in spherical shape and size is ~80 nm, ~350 nm and ~1.2 μm for ZrO2 annealed at 850°C, 1250°C and 1450°C respectively. Diffused reflectance (DR) spectra of the samples were used to determine optical band gap. The band gap of samples is slightly decreased with annealing temperature due to the crystallite size effect. PL emission band was observed at 499 nm under 297 nm excitation, the effect of annealing and ion fluence on PL response were discussed. The TL glow curves were measured at 5°C s−1 show the first peak at 418 K in all the samples and second peak at 497 K in the sample annealed at 850°C. The high temperature peak (500 K) intensity increases with increase of ion fluence and this peak position is depend on dose in ZrO2 annealed at 1250°C. Further, ZrO2 annealed at 1450°C show a strong glow peak at 510 K and this peak is consistent with ion fluence. The significant glow peak temperature changes with annealing temperature and the influence of dose on kinetic parameters were discussed. The activation energy of Si7+ ion irradiated (1 × 1012 ions cm−2) ZrO2 were found to be 1.14 eV (418 K), 1.55 eV (500 K) and 1.87 eV (511 K) for 850, 1250 and 1450°C annealed sample respectively.