DSpace Community: Associate Professor, PUC Campus, Aizawl

Thermoluminescence (TL) characteristics of Ba1-xCaxSO4:Eu nanophosphor

2024-06-18T10:30:05Z

Title: Thermoluminescence (TL) characteristics of Ba1-xCaxSO4:Eu nanophosphor Authors: Devi, Rangeela Y Abstract: TL phosphor based on Ba1−x CaxSO4:Eu (1 at %) (0 < x < 1) was prepared using the chemical co-precipitation technique. XRD shows orthorhombic structure. It was found that the TL sensitivity of the material changes on varying the concentration of Ca and maximum sensitivity is found for Ba0.98Ca0.01SO4:Eu.01. Moreover, the phosphor had constant glow curve shape over a dose range of 100-1000Gy. The dose response is linear/sub-linear over the dose range 100-500 Gy, above which TL sensitivity saturates.

A Thorough Investigation of Electronic, Optical, Mechanical, and Thermodynamic Properties of Stable Glasslike Sodium Germanate under Compressive Hydrostatic Pressure: Ab Initio Study

2024-06-18T10:25:12Z

Title: A Thorough Investigation of Electronic, Optical, Mechanical, and Thermodynamic Properties of Stable Glasslike Sodium Germanate under Compressive Hydrostatic Pressure: Ab Initio Study Authors: Devi, Rangeela Y Abstract: In this paper, we have tried to elucidate the variation of structural, electronic, and thermodynamic properties of glasslike Na2GeO3 under compressive isotropic pressure within a framework of density functional theory (DFT). The result shows stable structural (orthorhombic → tetragonal) and electronic (indirect → direct) phase transitions at P ∼ 20 GPa. The electronic band gap transition plays a key role in the enhancement of optical properties. The results of the thermodynamic properties have shown that Na2GeO3 follows Debye’s lowtemperature specific heat law and the classical thermodynamic of the Dulong−Petit law at high temperature. The pressure sensitivity of the electronic properties led us to compute the piezoelectric tensor (both in relaxed and clamped ions). We have observed significant electric responses in the form of a piezoelectric coefficient under applied pressure. This property suggested that Na2GeO3 could be a potential material for energy harvest in future energy-efficient devices. As expected, Na2GeO3 becomes harder and harder under compressive pressure up to the phase transition pressure (∼20 GPa) which can be read from Pugh’s ratio (kH) > 1.75, however, at pressures above 20 GPa kH < 1.75, which may be due to the formation of fractures at high pressure

The dependence of peak intensity of a thermoluminescence (TL) peak under the one- trap-onerecombination centre (OTOR) model on the initial occupancy of electrons/ holes is considered for different heating schemes. It is observed that for linear heating scheme, ImTm 2(Im=peak intensity, Tm =peak temperature) is proportional to initial concentration of trapped electrons (n0) i.e., to radiation dose. For hyperbolic heating scheme, Im is proportional to n0. These results will be of significance in TL dosimetry and dating.

2024-06-18T10:21:36Z

Title: The dependence of peak intensity of a thermoluminescence (TL) peak under the one- trap-onerecombination centre (OTOR) model on the initial occupancy of electrons/ holes is considered for different heating schemes. It is observed that for linear heating scheme, ImTm 2(Im=peak intensity, Tm =peak temperature) is proportional to initial concentration of trapped electrons (n0) i.e., to radiation dose. For hyperbolic heating scheme, Im is proportional to n0. These results will be of significance in TL dosimetry and dating. Authors: Devi, Rangeela Y Abstract: The dependence of peak intensity of a thermoluminescence (TL) peak under the one- trap-onerecombination centre (OTOR) model on the initial occupancy of electrons/ holes is considered for different heating schemes. It is observed that for linear heating scheme, ImTm 2(Im=peak intensity, Tm =peak temperature) is proportional to initial concentration of trapped electrons (n0) i.e., to radiation dose. For hyperbolic heating scheme, Im is proportional to n0. These results will be of significance in TL dosimetry and dating.

On the initial occupancy dependence of thermoluminescence under the OTOR model with different heating profiles

2024-06-18T10:18:14Z

Title: On the initial occupancy dependence of thermoluminescence under the OTOR model with different heating profiles Authors: Devi, Rangeela Y Abstract: The dependence of peak intensity of a thermoluminescence (TL) peak under the one- trap-onerecombination centre (OTOR) model on the initial occupancy of electrons/ holes is considered for different heating schemes. It is observed that for linear heating scheme, ImTm 2(Im=peak intensity, Tm =peak temperature) is proportional to initial concentration of trapped electrons (n0) i.e., to radiation dose. For hyperbolic heating scheme, Im is proportional to n0. These results will be of significance in TL dosimetry and dating.