Kinetic Analysis of Thermoluminescence

Jipa

Physica Status Solidi (b)

et al. 2008

The thermoluminescence (TL) glow curve recorded after gamma‐irradiation at room temperature of Mn2+‐doped MgF2 phosphor shows two intense TL peaks at 364 K and 420 K accompanied by several weaker peaks up to 600 K. The TL spectra have shown Mn2+ luminescence at about 560 nm. The 364 K TL peak disappears after one day of storage, and so is probably related to the recombination of carriers from some shallow traps. Based on thermal bleaching and optical bleaching (in the 260 nm F‐centre absorption band) experiments, the 420 K TL peak was ascribed to the thermally activated recombination between an F‐centre and a hole centre trapped in the neighbourhood of the Mn2+ impurity which results in Mn2+ luminescence. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Section: +mentioning

confidence: 82%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Processes involved in the high‐temperature thermoluminescence of a Mn²⁺‐doped MgF₂ phosphor

Jipa

Physica Status Solidi (b)

et al. 2008

“…When this retrapping process is significant, the depopulation of carriers with temperature is slower and follows what is called a second-order model 48 , where the luminescence decays more slowly with increasing temperature than a first-order model would predict. There are also other higher-, general-, and mixed-order models to describe other variations in TL glow curves, as well as a push to replace the entire order-of-kinetics model [51][52][53][54] . Other models include a semi-localized transition model 55 which has been invoked to explain non-physical frequency factors, where the factor s from Equation (1) has values far beyond any possible phonon interaction frequency, and anomalous heating rate effects, where the number of photons emitted increases with heating rate.…”

Section: Alternative Trap Modelsmentioning

confidence: 99%

Thermoluminescent microparticle thermal history sensors

et al. 2016

While there are innumerable devices that measure temperature, the nonvolatile measurement of thermal history is far more difficult, particularly for sensors embedded in extreme environments such as fires and explosions. In this review, an extensive analysis is given of one such technology: thermoluminescent microparticles. These are transparent dielectrics with a large distribution of trap states that can store charge carriers over very long periods of time. In their simplest form, the population of these traps is dictated by an Arrhenius expression, which is highly dependent on temperature. A particle with filled traps that is exposed to high temperatures over a short period of time will preferentially lose carriers in shallow traps. This depopulation leaves a signature on the particle luminescence, which can be used to determine the temperature and time of the thermal event. Particles are prepared-many months in advance of a test, if desired-by exposure to deep ultraviolet, X-ray, beta, or gamma radiation, which fills the traps with charge carriers. Luminescence can be extracted from one or more particles regardless of whether or not they are embedded in debris or other inert materials. Testing and analysis of the method is demonstrated using laboratory experiments with microheaters and high energy explosives in the field. It is shown that the thermoluminescent materials LiF:Mg,Ti, MgB 4 O 7 :Dy,Li, and CaSO 4 :Ce,Tb, among others, provide accurate measurements of temperature in the 200 to 500°C range in a variety of high-explosive environments.

Phys. Status Solidi (c)

“…The utility of thermoluminescence (TL) in detecting changes in defect concentration in insulators is well established [1][2][3]. The underlying premise leading to the emission of TL is that exposure of a material to ionizing radiation causes a redistribution of charge in defect centres within the material.…”

Section: Introductionmentioning

confidence: 99%

Accuracy of the activation energy calculated from a thermoluminescence glow‐peak using a method that uses three points on the peak

Ogundare¹,

Chithambo²

2006

PACS 78.60.Kn This paper shows that the limitations of the general-order and peak-shape methods of kinetic analysis in cases where the retrapping probability greatly exceeds the recombination probability may be avoided if the analysis method proposed by Rasheedy [6-8] is applied. Analysis of computer simulated glow-curves using the general-order, peak-shape, and Rasheedy's protocol showed that Rasheedy's method gave the best agreement between calculated and default values. The accuracy of the method improved for data selected well below 10% of the peak maximum in the initial-rise region of a glow-peak. The observed improvement has been attributed to the fact that in the initial-rise region, the quasiequilibrium condition is better satisfied than at the higher temperature end of the glow-peak. In general, we find that when the retrapping probability increases, the analysis for kinetic parameters is better carried out on data selected well below 10% of maximum peak intensity.