Simulation of thermoluminescence glow curves for ZrO2 from kinetics parameters determined by a peak shape method

Full text: To assess the effects produced by changes in the values of the thermoluminescent (TL) glow curves trap parameters, a simulation program was developed starting from theoretical assumptions. TL glow curves of ZrO2 were experimentally obtained from samples exposed to 260 nm ultraviolet (UV) radiation. An analytical method was applied to extract information from a glow peak, using the temperature at the maximum emission, TM, the low temperature in half intensity, T1, and high temperature in half intensity, T2. Geometrical parameters and symmetry factor were calculated using these temperature values and the order of the kinetics, b, was determined as a function of this symmetry factor by means of an interpolation in the Chen's plot. The value obtained for the kinetics order was 2.3. In order to calculate the frequency factor value, s, an expression from the May and Partridge's general order kinetics empirical equation was generated. Combining all the information into a mathematical algorithm, the simulation program was generated and simulated TL glow curves were obtained. Three major parameters were analyzed named heating rate, β, initial concentration of electrons in traps or holes in centers, n0, and activation energy, Et, varying their values to analyze the TL glow curves behavior which was similar to that corresponding to second order kinetics; however, the values of the asymmetry factors give an indication of first order kinetics. This duality suggests a more complex interaction between centers and holes than that known for values of the kinetic order in the range of 1 to 2