THERMOLUMINESCENCE AND KINETIC PARAMETERS OF MICRO-NANO MATRIX OF LITHIUM TRIBORATE AND ZINC OXIDE NANOPARTICLE.

Abstract

This study presents the first report on the kinetic parameters of micro-nano interaction of lithium triborate microparticles doped with zinc oxide nanoparticles (LBZ) in 0.1 to 0.4% dopant concentrations. The parent-dopant mix was synthesized using high-temperature solid-state method. The materials were subjected to X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and differential thermal analysis (DTA) to ascertain their structural, physical properties as well as gamma irradiation and thermoluminescence (TL) analysis for their dosimetric properties. XRD and DTA confirmed the formation of polycrystalline lithium triborate compounds, while SEM and EDS showed the presence of the dopant. TL analysis presented a simple glow curve structure with the main temperature peak for different dopant concentrations varying from 243 to 327°C. The activation energy (E) and frequency factor (s) were calculated for each peak shape parameter τ (low temperature half width), δ (high temperature half-width) and ω (total half width) using Chen's peak shape (PS) method and the order of kinetics was deduced from the symmetry factor (μg) and gamma dose-response curves. The activation energy and frequency factor with respect to the peak shape parameters Eτ, Eδ, Eω and sτ, sδ, sω across the dopant concentrations were in the range of 1.14 to 2.2eV and 3.92 × 1010 to 7.71 × 1022s-1, respectively. Comparing the methods for the determination of the order of kinetics, LBZ 0.2% agrees with the conditions of first-order kinetics, while second-order kinetics is assigned to LBZ 0.1, 0.3 and 0.4%. The results present simple glow curve structure which relates to stability, high-temperature peaks and E values which correspond to deep trap states.