Synthesis, characterization and DFT calculations of electronic and optical properties of CaMoO4

Bouzidi, C.; Horchani−Naifer, Karima; Khadraoui, Z.; Elhouichet, Habib; Férid, Mokhtar

doi:10.1016/j.physb.2016.06.009

Cited by 38 publications

(13 citation statements)

References 28 publications

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“…In this regard, it should be pointed out that the Tauc’s equation alone is not enough to specify the type of transition, since four figures is needed to be plotted depending on the values that the exponent takes [15]. From a quantum mechanics viewpoint, the existence of strong correlation between optical dielectric loss ( ε 2 ) and band structure of the materials is a subject of various theoretical studies [46,50,51,52]. The use of ε 2 to estimate the optical band gap, is related to the fact that ε 2 is a function of the electronic band-structure, density of filled and empty states and magnitude of optical transition probability between the filled and empty states [53,54], as follows:

ε_{2} false(ω false) = \frac{4 π^{2}}{sans-serifΩ ω^{2}} {true \sum_{i \in V B . j \in C B} true \sum_{K} W_{K} | p_{i j}^{a} |}^{2} δ false(\in_{k j} - \in_{k i} - ω false)

where Ω is the unit-cell volume and ω is photon frequency, VB and CB denote the valence and conduction bands, W k is the weight associated with a k -point,

p_{i j}^{a}

is the transition probability and a denotes a particular direction.…”

Section: Resultsmentioning

confidence: 99%

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Morphological and Optical Characteristics of Chitosan(1−x):Cuox (4 ≤ x ≤ 12) Based Polymer Nano-Composites: Optical Dielectric Loss as an Alternative Method for Tauc’s Model

Aziz

2017

Nanomaterials

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In this work, copper (Cu) nanoparticles with observable surface plasmonic resonance (SPR) peaks were synthesized by an in-situ method. Chitosan host polymer was used as a reduction medium and a capping agent for the Cu nanoparticles. The surface morphology of the samples was investigated through the use of scanning electron micrograph (SEM) technique. Copper nanoparticles appeared as chains and white specks in the SEM images. The strong peaks due to the Cu element observed in the spectrum of energy dispersive analysis of X-rays. For the nanocomposite samples, obvious peaks due to the SPR phenomena were obtained in the Ultraviolet-visible (UV-vis) spectra. The effect of Cu nanoparticles on the host band gap was understood from absorption edges shifting of absorption edges to lower photon energy. The optical dielectric loss parameter obtained from the measurable quantities was used as an alternative method to study the band structure of the samples. Quantum mechanical models drawbacks, in the study of band gap, were explained based on the optical dielectric loss. A clear dispersion region was able to be observed in refractive indices spectra of the composite samples. A linear relationship with a regression value of 0.99 was achieved between the refractive index and volume fractions of CuI content. Cu nanoparticles with various sizes and homogenous dispersions were also determined from transmission electron microscope (TEM) images.

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ε_{2} false(ω false) = \frac{4 π^{2}}{sans-serifΩ ω^{2}} {true \sum_{i \in V B . j \in C B} true \sum_{K} W_{K} | p_{i j}^{a} |}^{2} δ false(\in_{k j} - \in_{k i} - ω false)

where Ω is the unit-cell volume and ω is photon frequency, VB and CB denote the valence and conduction bands, W k is the weight associated with a k -point,

p_{i j}^{a}

is the transition probability and a denotes a particular direction.…”

Section: Resultsmentioning

confidence: 99%

“…The optical band gap has been studied by other researchers both experimentally and theoretically [50,54]. They observed that the experimental values for the band gap energy are found to be larger than the theoretical values.…”

Section: Resultsmentioning

confidence: 99%

Morphological and Optical Characteristics of Chitosan(1−x):Cuox (4 ≤ x ≤ 12) Based Polymer Nano-Composites: Optical Dielectric Loss as an Alternative Method for Tauc’s Model

Aziz

2017

Nanomaterials

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“…(2). It was deduced in the previous studies that the peaks that emerged in the spectra of the ɛ i have a direct correlation with the interband transitions 72,[77][78][79] . Hence, it is possible to attain the real energy gap using the intersection of linear parts of ɛ i spectra on the horizontal axis of photon energy (refer to Fig.…”

Section: Morphological Study Polymer Macromolecules and Polymer Matementioning

confidence: 91%

Tea from the drinking to the synthesis of metal complexes and fabrication of PVA based polymer composites with controlled optical band gap

Brza

Aziz

Anuar

et al. 2020

Sci Rep

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In the present study black tea extract (BTE) solution which is familiar for drinking was used to prepare cerium metal-complexes (Ce(III)-complex). The prepared Ce(III)-complex was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV–Vis spectroscopy. The results indicate that BTE solution is a novel green coordination chemistry approach for the synthesis of metal complexes. The outcomes signify that coordination occurs between cerium cations and polyphenols. The synthesis of metal-complexes with superior absorption performance in the visible region is a challenge for optoelectronic device applications. The suspended Ce(III)-complex in distilled water was mixed with poly (vinyl alcohol) (PVA) polymer to fabricate PVA/ Ce(III)-complex composites with controlled optical properties. The PVA/Ce(III)-complexes composite films were characterized by FTIR, XRD, and UV–Vis spectroscopy. The XRD findings confirms the amorphous structure for the synthesized Ce(III)-complexes. The addition of Ce(III)-complex into the PVA host polymer led to the growth of polymer composites with controllable small optical band gaps. It is shown by the FTIR spectra of the composite films that the functional groups of the host PVA have a vigorous interaction with the Ce(III)-complex. The XRD deconvolution on PVA composites reveals the amorphous phase enlargement with increasing Ce(III)-complex concentration. It is indicated in the atomic force microscopy (AFM) that the surface roughness in the doped PVA films increases with the increase of the Ce(III)-complex. There is a decrease in absorption edge from 5.7 to 1.7 eV. It becomes possible to recognize the type of electron transition by studying both the Tauc's model and optical dielectric loss (ɛi) parameter.

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“…Now, there are about one and a half million electronic band structures of crystals in AFLOW database [207], [208], which is very useful as the first estimation of electronic properties of new scintillators. Definitely, much more reliable investigations were made for different first-principles calculations of specific crystals (see [209] as an example). Fairly good progress was achieved in first-principles calculation of activators, both rare earth ions (see [210] and [211]) and heavy ions [212], [213].…”

Section: Theory and Modelingmentioning

confidence: 99%

Needs, Trends, and Advances in Inorganic Scintillators

Dujardin

Auffray

Bourret-Courchesne

et al. 2018

IEEE Trans. Nucl. Sci.

388

240

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This paper presents new developments in inorganic scintillators widely used for radiation detection. It addresses major emerging research topics outlining current needs for applications and material sciences issues with the overall aim to provide an up-to-date picture of the field. While the traditional forms of scintillators have been crystals and ceramics, new research on films, nanoparticles, and microstructured materials is discussed as these material forms can bring new functionality and therefore find applications in radiation detection. The last part of the contribution reports on the very recent evolutions of the most advanced theories, methods, and analyses to describe the scintillation mechanisms.

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Synthesis, characterization and DFT calculations of electronic and optical properties of CaMoO4

Cited by 38 publications

References 28 publications

Morphological and Optical Characteristics of Chitosan(1−x):Cuox (4 ≤ x ≤ 12) Based Polymer Nano-Composites: Optical Dielectric Loss as an Alternative Method for Tauc’s Model

Morphological and Optical Characteristics of Chitosan(1−x):Cuox (4 ≤ x ≤ 12) Based Polymer Nano-Composites: Optical Dielectric Loss as an Alternative Method for Tauc’s Model

Tea from the drinking to the synthesis of metal complexes and fabrication of PVA based polymer composites with controlled optical band gap

Needs, Trends, and Advances in Inorganic Scintillators

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