@article{d51e11edfe164b6987a697c76287d922,
title = "Exploring sources of variation in thermoluminescence emissions and anomalous fading in alkali feldspars",
abstract = "Alkali feldspars are routinely used in retrospective dosimetry using luminescence methods. However there is a signal loss over time, termed {\textquoteleft}anomalous fading{\textquoteright}, which results in age underestimation if uncorrected. Although significant improvements have been made in recent years, luminescence dating of feldspars remains challenging. This paper investigates the relationships between chemistry, structural state and the scale of exsolution with thermoluminescence (TL) emission spectra and infrared stimulated luminescence (IRSL) fading rates. We measure TL emission spectra, where possible linking the recombination site to physical features of the feldspar crystals. We show that fading rates are lowest in ordered end-member Na- and K-feldspars but significantly greater in disordered end-members, showing that Al–Si order influences fading. As well as having very low fading rates, ordered end-member samples have distinctive TL emission spectra, with the yellow-green emission dominant, while all other samples have a dominant blue emission. Perthites, i.e. exsolved members of the (Na,K)-feldspar solid solution, show greater fading than disordered end-members and fading is greatest in semi-coherent macroperthite. We propose that the state of Al–Si-order, and the occurrence of defects and dislocations at the perthite lamellar interfaces influence anomalous fading rates in feldspars.",
keywords = "Alkali feldspar, Emission spectra, Fading rate, Framework disorder, Thermoluminescence",
author = "S. Riedesel and Bell, {A. M.T.} and Duller, {G. A.T.} and Finch, {A. A.} and M. Jain and King, {G. E.} and Pearce, {N. J.} and Roberts, {H. M.}",
note = "Funding Information: SR would like to thank Aberystwyth University for funding her PhD research through an AberDoc PhD scholarship (Aberystwyth University). Sample WHB-7 was taken during a field campaign in May 2018, which was made possible by a RGS-IBG postgraduate research grant awarded to SR. Sample HAM-5 was taken in the framework of the QuakeRecNankai project, funded by the Belgian Science Policy Office (BELSPO BRAIN-be BR/121/A2). We thank Dr Javier Garcia-Guinea for CLBR and Dr Renske Lambert for MBT-I-2430. The authors would like to thank Prof Mike Henderson (Manchester University) for facilitating the introduction between some of the authors. SR would like to thank Karsten Bracht-Nielsen (Technical University of Denmark) for technical support with the Andor Spectrometer, and Andrew Brown (Aberystwyth University) for laboratory assistance during the heating experiments. We would like to thank three anonymous referees for their constructive comments, which improved the manuscript. Funding Information: SR would like to thank Aberystwyth University for funding her PhD research through an AberDoc PhD scholarship ( Aberystwyth University ). Sample WHB-7 was taken during a field campaign in May 2018, which was made possible by a RGS-IBG postgraduate research grant awarded to SR. Sample HAM-5 was taken in the framework of the QuakeRecNankai project, funded by the Belgian Science Policy Office ( BELSPO BRAIN-be BR/121/A2). We thank Dr Javier Garcia-Guinea for CLBR and Dr Renske Lambert for MBT-I-2430. The authors would like to thank Prof Mike Henderson (Manchester University) for facilitating the introduction between some of the authors. SR would like to thank Karsten Bracht-Nielsen (Technical University of Denmark) for technical support with the Andor Spectrometer, and Andrew Brown (Aberystwyth University) for laboratory assistance during the heating experiments. We would like to thank three anonymous referees for their constructive comments, which improved the manuscript. Publisher Copyright: {\textcopyright} 2021 Elsevier Ltd",
year = "2021",
month = feb,
day = "8",
doi = "10.1016/j.radmeas.2021.106541",
language = "English",
volume = "141",
journal = "Radiation Measurements",
issn = "1350-4487",
publisher = "Elsevier",
}