THERMOLUMINESCENCE KINETICS OF PYRITE (FES2)

Thermoluminescence (TL) of pyrite (FeS2) has been investigated to study the kinetics of single peak glow curves. The material used normally exhibits one large and four small peaks. However, a glow curve can be obtained with only the large single peak that is suitable for testing TL kinetics. Glow curves from aliquots of a single natural pyrite crystal studied in detail contain two low intensity TL peaks at congruently to 90 and congruenty to 165-degrees-C that are easily "drained" by careful pre-heating, a single high intensity TL peak at congruently to 250-degrees-C, and two chemiluminescence (CL) peaks at congruently to 350 and congruently to 430-degrees-C. The CL pe are largely removable by initially heating the sample chamber under vacuum, pumping through liquid nitrogen traps, and recording glow curves immediately after helium is introduced, procedures which reduce system contaminants that react with pyrite. The shape, the variation of the temperature of the peak maximum (T(max)) with dose, and the re-trapping to recombination cross-section ratio (sigma) of the large 250-degrees-C peak are better described by the general one trap (GOT) kinetic equation, the basic equation from which the first and second order kinetic equations are obtained as special cases (see text), than by the first or second order equations.