UV photoluminescence from small particles of calcium cadmium sulfide solid solutions

Barrett, Emma; Fern, George R.; Ray, B.; Robert, Withnall; Silver, Jack

doi:10.1088/1464-4258/7/6/002

Cited by 5 publications

(5 citation statements)

References 15 publications

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“…Thus, the blue/green ratio decreases as the excitation wavelength increases. This is broadly in line with previous observations in CaS lattice [20]. This is indicative of a progressive random distribution of cadmium and strontium sub-lattices with a shift in band location in k-space arising from the introduction of an indirect band gap, SrS into the CdS lattice.…”

Section: Resultssupporting

confidence: 92%

Synthesis and luminescence studies of CdSrS nanostructures

Chawla

Lochab

Singh

2011

Journal of Alloys and Compounds

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Section: Resultssupporting

confidence: 92%

Synthesis and luminescence studies of CdSrS nanostructures

Chawla

Lochab

Singh

2011

Journal of Alloys and Compounds

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“…With the presence of Fe, the solid residue have an absorbance between 200 and 500 nm in the UV-Visible region. Optimum photoluminescence occurs at 298 nm, this value is consistent with that given by Barrett et al [55] Pure CaS shows a strong peak around 220 nm with a small shoulder at 250 nm. [56] CaS sample, prepared by mixing Ca(CH 3 CO 2 ) 2 and Na 2 S, shows absorbance peak at 405 nm.…”

Section: Characterization Of Raw Materials and Residuessupporting

confidence: 92%

“…The absorbance between 200 and 500 nm is of low intensity and due to the presence of CaS in solid residue. [55][56][57][58] This low intensity is due to the fact that calcium sulfide is unstable in water, and requires special precautions during preparation and storage. It will hydrolyze to form hydrates and easily dissolves in an acid solution.…”

Section: Characterization Of Raw Materials and Residuesmentioning

confidence: 99%

Reduction of phosphogypsum to calcium sulfide (CaS) using metallic iron in a hydrochloric acid medium

Alla

Harrou

Elhafiany

et al. 2022

Phosphorus, Sulfur, and Silicon and the Related Elements

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Our study aims to decompose phosphogypsum (PG), mainly composed of CaSO 4 .2H 2 O, by reduction in an acidic medium. We evaluated the decomposition of PG by various reaction mechanisms. Sulfate ions from the acid digestion of PG are reduced to sulfide by the hydrogen gas produced in the solution by hydrochloric attack of the metal iron. The solid residues obtained have been determined and monitored by X-Ray Diffraction, Fourier-Transform Infrared spectroscopy and Ultraviolet-visible spectroscopy. The microstructure of residues was observed by scanning electron microscope (SEM). The results show that hydrogen gas formed by hydrochloric acid attack of iron reduces the sulfur from S(VI) to S(-II). CaSO 4 .2H 2 O, insoluble in water, gives a residue containing CaS, which is only sparingly soluble in water. The residue also contains anhydrite, bassanite and ferrous chloride. The monitoring of the quantities of residue obtained under varying experimental conditions (temperature, attack time, mass of iron and PG and volume of acid on PG) and volume of HCl showed that the amounts of residue obtained are less than 32% of mass. When the volume of the HCl added increases, the obtained mass of the solid residue decreases sharply. The residue stabilizes at 10% of mass when the volume of HCl added is higher than that required to attack metal iron.

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“…225) and large unit cell of 5.68 Å . Owing to the wide band-gap ($ 5.38 eV), CaS is technologically important as a host material in luminescence technology (Rao, 1986;Versluys et al, 2001;Hakamata et al, 2005;Barrett et al, 2005). Meanwhile, it also exhibits unique structural behavior under high pressure.…”

Section: Introductionmentioning

confidence: 99%

Electronic structure and hybridization of CaS by means of X-ray absorption spectroscopy at Ca and S K-edges

Liu

Cui

et al. 2012

J Synchrotron Radiat

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The cubic calcium sulfide (CaS) is a well known system and an attractive building block material for many luminescence technological applications. However, it is essential to achieve an accurate understanding of its electronic structure in order to engineer its band structure for optimized applications. Here a study of the electronic structure of CaS by means of X-ray absorption spectroscopy performed at both Ca and S K-edges, and calculations performed in the framework of the multiple-scattering theory and of the finite difference method are presented. At the Ca K-edge the presence of an anomalous d states feature is discussed while in the S K-edge spectrum the presence of a pre-edge shoulder owing to the hybridization among Ca d states and S p states is pointed out. Although the l-projected density of states of CaS is in good agreement with previous first-principles calculations, the standard muffin-tin potential is inadequate to reproduce near-edge structures at both Ca and S K-edges in this system. Indeed, with its highly symmetric and less compact structure, CaS is characterized by a large set of collinear atomic configurations that pose severe constraints on the construction of the atomic potential. On the contrary, the finite-difference method with no muffin-tin approximation is more suitable for X-ray absorption calculations in this system.

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UV photoluminescence from small particles of calcium cadmium sulfide solid solutions

Cited by 5 publications

References 15 publications

Synthesis and luminescence studies of CdSrS nanostructures

Synthesis and luminescence studies of CdSrS nanostructures

Reduction of phosphogypsum to calcium sulfide (CaS) using metallic iron in a hydrochloric acid medium

Electronic structure and hybridization of CaS by means of X-ray absorption spectroscopy at Ca and S K-edges

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