YIN Li-hong, QIAO Sen, PAN Lu, WANG Ya-fang*
(School of Science, China University of Geosciences (Beijing), Beijing100083, China)
Abstract: Thermoluminescence signals from crystals are closely related to lattice defects which were created in the growth process of crystal. The defects could be produced by the mixing of the impurity ions or the damage of complete crystal lattice by the nuclear irradiation. Therefore, the thermoluminescence property of natural minerals is one of physical properties of crystal lattice defects of minerals. In this paper, nine natural calcite samples from different places were selected for measuring their chemical compositions and three-dimensional thermoluminescence spectra after being irradiated by X rays. Then the obtained measured results for all samples have been analyzed and discussed. The results indicate that the thermoluminescence emission of calcite is mainly resulted from the Mn2+ in lattice of calcite for all the samples. Meanwhile, the emission intensity and peak temperature values of the thermoluminescence signal from calcite are influenced by concentrations of both the luminescence centers (Mn) and quenching centers (Fe, Co, Ni). The possible energy depths of the lattice defects of calcites quantitatively calculated by using the glow curves of thermoluminescence spectra are 1.0～1.1eV, 1.4 eV, and 1.7 eV, respectively. In addition, the comparison of natural thermoluminesceence and X-ray irradiated thermoluminesceence of calcites has indicated that artificial irradiation could result in the re-distribution of captured electrons in the crystal structures of calcites.
Keywords: crystal defects; calcite; thermoluminescence
ACTA MINERALOGICA SINICA Vol. 41, No.3, 2021, page 301-311