Photoluminescence and Thermoluminescence Glow Curve Analysis of Calcite Collected From Meghalaya Basin

An analysis of the photoluminescence (PL) and thermoluminescence (TL) glow curves from the calcite sample collected from the Meghalaya basin is reported. The as-collected sample is thoroughly ground with an agate pestle-and-mortar set for 4 h and is annealed at 400 degrees C for 2 h. An X-ray diffraction (XRD) analysis of the sample reveals cubic crystal structure. The collected sample morphology shows the presence of agglomeration. The bending and stretching of bonds inside the calcite in the fingerprint region is determined by the Fourier transform infrared (FTIR) spectroscopy. The photoluminescence excitation and emission spectra are monitored; they show well resolved peaks at 252 nm (absorption band), 395 nm and 509 nm (emission bands). An analysis of the thermoluminescence (TL) glow curve of calcite is performed using UV excitation for different UV exposure times (5 and 15 minutes), showing a linear response with the UV dose. The corresponding kinetic parameters, like order of kinetics, activation energy and frequency factor, are calculated using the computerized glow curve deconvolution (CGCD) technique. The collected calcite sample shows a good response with the dose, which may be useful for the environmental UV monitoring systems.