1999/06/09 by J.F. de Lima, J. F. de Lima, de Lima, J. F. +6
Chemistry · Engineering · Physics and Astronomy · #FOS: Physical sciences #Gas Sensing Nanomaterials and Sensors #Materials Science (cond-mat.mtrl-sci) #Photochemistry and Electron Transfer Studies #Spectroscopy and Quantum Chemical Studies #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.cond-mat/9906122
11 pages, 7 figures, submitted to Phys. Rev. B on June 07, 1999
openalex publication_date 1999/06/09 · arxiv created 1999/06/10 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this work we investigate the effect of gamma and ultraviolet radiations on the thermoluminescence of Brazilian calcite. The irradiated samples presented three TL peaks at 150, 245 and 320oC (at a linear heating rate of 1.8oC/s), with a main emission band centered at 615nm due to the 4G → 6S transition of the Mn2+. The irradiated samples presented, besides the Mn2+ signals, three lines related related to carbonate groups. The thermal treatment and the irradiation effects on the ESR signal lead to the conclusion that (CO3)3-, stabilized in two different symmetries, and the (CO2)- ions are the electron trapping centers. It was found that the TL peaks follows a t-1 decay as a function of the UV illumination time. An alternative model for the TL emission of calcite is discussed, considering that the recombination of charges is processed via a thermally assisted tunnelling mechanism.