Investigation of the effect of particle size on the optical and electronic properties of Ba1-xSrxTiO3 composite ceramics

1997 ◽  
Vol 17 (1-4) ◽  
pp. 287-296 ◽  
Author(s):  
L. C. Sengupta ◽  
J. Synowcyznski ◽  
L. H. Chiu
Keyword(s):  
Particle Size ◽  
Electronic Properties ◽  
Composite Ceramics ◽  
Optical And Electronic Properties ◽  
Effect Of Particle Size

scholarly journals The effect of particle size on the optical and electronic properties of magnesium oxide nanoparticles

2021 ◽  
Vol 23 (38) ◽  
pp. 21579-21590
Author(s):  
Martijn A. Zwijnenburg
Keyword(s):  
Particle Size ◽  
Electronic Properties ◽  
Magnesium Oxide ◽  
Oxide Nanoparticles ◽  
Mgo Nanoparticles ◽  
Magnesium Oxide Nanoparticles ◽  
Optical And Electronic Properties ◽  
Effect Of Particle Size

We use evGW/BSE calculations to demonstrate that the optical and electronic properties of MgO nanoparticles are governed by the low-coordinated atoms on their surfaces.

scholarly journals The Effect of Particle Size on the Optical and Electronic Properties of MgO Nanoparticles

2021 ◽  
Author(s):  
Martijn Zwijnenburg
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Coupled Cluster ◽  
Reflection Spectra ◽  
Edge States ◽  
Coupled Cluster Theory ◽  
Mgo Nanoparticles ◽  
Optical Gap ◽  
Optical And Electronic Properties ◽  
Effect Of Particle Size

<i>evGW</i>-BSE is used to predict the (band) edge states, fundamental gap, optical gap, exciton binding energy and UV-Vis absorption spectra for a series of cuboidal MgO rocksalt nanoparticles, the largest of with has 216 atoms and edges of 1 nm. The evolution of the electronic and optical properties with particle size was studied, where it was found that while the edge states and fundamental gap change with particle size, the optical gap remains essentially fixed for cuboid nanoparticles containing 48 atoms or more. The explanation for that observation is that while the optical gap is associated with an exciton that is well localised on the magnesium corner atoms and the oxygen atoms directly surrounding it, the edge states, while primarily localised on the magnesium corner atoms (electron) and oxygen corner atoms (hole), show significant delocalisation along the edges away from the corner atoms. The BSE/ev<i>GW</i> optical gap for the smallest particles, the (MgO)<sub>4 </sub>cube, matches with that obtained independently from coupled cluster theory, while for the (MgO)<sub>32</sub>, a cube with edges of 0.6 nm, the BSE/ev<i>GW</i> predicted excitation spectrum agrees well with the experimentally reported reflection spectra of MgO nanoparticles. <br>

Eco-Friendly Techniques to Synthesize Quantum Dots

2021 ◽  
pp. 1-52
Keyword(s):  
Quantum Dots ◽  
Particle Size ◽  
Solid State ◽  
Quantum Dot ◽  
Electronic Properties ◽  
Quantum Effects ◽  
Nano Technology ◽  
Major Topic ◽  
Optical And Electronic Properties ◽  
Wet Chemical

Quantum dot defines as a nanoparticle with particle size smaller than its exciton Bohr radius. Due to the remarkable quantum effects such as optical and electronic properties, they have attracted a great deal of attention by researchers and industries. Therefore, quantum dots have become a major topic in nano-technology. Here, we describe the most recent eco-friendly techniques that have been used to synthesize quantum dots, including biogenic methods, such as plant-mediated, microorganisms-mediated methods, wet chemical and solid-state methods.

scholarly journals The Effect of Particle Size on the Optical and Electronic Properties of MgO Nanoparticles

2021 ◽  
Author(s):  
Martijn Zwijnenburg
Keyword(s):  
Particle Size ◽  
Surface Defects ◽  
Binding Energies ◽  
Edge States ◽  
Many Body ◽  
Mgo Nanoparticles ◽  
Optical Gap ◽  
Optical And Electronic Properties ◽  
Many Body Perturbation Theory ◽  
Effect Of Particle Size

The (band) edge states, fundamental gaps, optical gaps, exciton binding energies and UV-Vis spectra for a series of cuboidal nanoparticles of the prototypical oxide magnesium oxide (MgO), the largest of with has 216 atoms and edges of 1 nm, were predicted using many-body perturbation theory (ev<i>GW</i>-BSE). The evolution of the properties with particle size was explicitly studied. It was found that while the edge states and fundamental gap change with particle size, the optical gap remains essentially fixed for all but the smallest nanoparticles, in line with what was previously observed experimentally. The explanation for these observations is demonstrated to be that while the optical gap is associated with an exciton that is highly localised around the particle’s corner atoms, the edge states, while primarily localised on the magnesium corner atoms ­(electron) and oxygen corner atoms (hole), show significant delocalisation along the edges. The strong localisation of the exciton associated with the optical gap on the corner atoms is argued to also explain why the nanoparticles have a much smaller optical gaps and red-shifted spectra than bulk MgO. Finally, it is discussed how this non-quantum confinement behaviour, where the properties of the nanoparticles arise from surface defects rather than differences in localisation of edge or exciton states, appears typical of alkaline earth oxide nanoparticles, and that the true optical gap of bulk crystals of such materials is also probably the result of surface defects, even if unobservable experimentally. <br>

scholarly journals The Effect of Particle Size on the Optical and Electronic Properties of MgO Nanoparticles

2021 ◽  
Author(s):  
Martijn Zwijnenburg
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Coupled Cluster ◽  
Reflection Spectra ◽  
Edge States ◽  
Coupled Cluster Theory ◽  
Mgo Nanoparticles ◽  
Optical Gap ◽  
Optical And Electronic Properties ◽  
Effect Of Particle Size

<i>evGW</i>-BSE is used to predict the (band) edge states, fundamental gap, optical gap, exciton binding energy and UV-Vis absorption spectra for a series of cuboidal MgO rocksalt nanoparticles, the largest of with has 216 atoms and edges of 1 nm. The evolution of the electronic and optical properties with particle size was studied, where it was found that while the edge states and fundamental gap change with particle size, the optical gap remains essentially fixed for cuboid nanoparticles containing 48 atoms or more. The explanation for that observation is that while the optical gap is associated with an exciton that is well localised on the magnesium corner atoms and the oxygen atoms directly surrounding it, the edge states, while primarily localised on the magnesium corner atoms (electron) and oxygen corner atoms (hole), show significant delocalisation along the edges away from the corner atoms. The BSE/ev<i>GW</i> optical gap for the smallest particles, the (MgO)<sub>4 </sub>cube, matches with that obtained independently from coupled cluster theory, while for the (MgO)<sub>32</sub>, a cube with edges of 0.6 nm, the BSE/ev<i>GW</i> predicted excitation spectrum agrees well with the experimentally reported reflection spectra of MgO nanoparticles. <br>

Effect of particle size on erosion measurements and predictions in annular flow for an elbow

Wear ◽  
2020 ◽  
pp. 203579
Author(s):  
G. Haider ◽  
M. Othayq ◽  
J. Zhang ◽  
R.E. Vieira ◽  
S.A. Shirazi
Keyword(s):  
Particle Size ◽  
Annular Flow ◽  
Effect Of Particle Size

The Effect of Particle Size and Phospholipid on Growth and Fat Utilization of the Baby Pig

1951 ◽  
Vol 10 (4) ◽  
pp. 867-874 ◽  
Author(s):  
B. E. Sheffy ◽  
Carlos Acevedo Gallegos ◽  
R. H. Grummer ◽  
P. H. Phillips ◽  
G. Bohstedt
Keyword(s):  
Particle Size ◽  
Fat Utilization ◽  
Effect Of Particle Size
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