Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1811747 | Physica B: Condensed Matter | 2017 | 5 Pages |
Abstract
CaS:Ce, Sm nanophosphors were synthesized via solid state diffusion method. X-Ray diffraction confirmed the cubic crystalline phase of CaS:Ce, Sm nanoparticles. The particle size calculated using Debye-Scherrer formula was found to be 52Â nm. The morphological investigations of the nanoparticles were made using TEM and found to have nearly spherical morphology with diameter 45-50Â nm, which is in close agreement with the XRD result. The PL emission characteristics of CaS:Ce, Sm as a function of cerium and samarium concentrations have been studied and CaS:Ce0.6Sm0.4 system has maximum emission intensity, hence it was opted for further studies. The CaS:Ce0.6Sm0.4 system showed independent emission of Sm and Ce when excited at 330 and 450Â nm, respectively. To study the energy transfer between cerium and samarium, the CaS:Ce0.6Sm0.4 was excited at wavelengths other than the excitation wavelengths of Ce (450Â nm) and Sm (330Â nm). The existence of Ce emission (at an excitation of 390Â nm) even in the absence of Ce excitation band and Sm emission at an excitation of 405Â nm, which is the excitation band of Ce, indicates the energy transfer at these two wavelengths. Thermoluminescence characteristics of 60Co irradiated CaS:Ce0.6Sm0.4 have been investigated for different doses of 0.14-125Â Gy. All the glow curves show a single peak at 475Â K. With increasing dose, the intensity of this peak increases and a shoulder is formed on the lower temperature side at 415Â K at 21Â Gy of exposure. CaS:Ce0.6Sm0.4 shows almost linear dose dependence up to 125Â Gy.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Geeta Sharma, S.P. Lochab, Nafa Singh,