The impact of Er/Yb co-doping on the spectroscopic performance of bismuth borophosphate glasses for photonic applications

Vacuum ◽  
2021 ◽  
Vol 183 ◽  
pp. 109788 ◽  
Author(s):  
K.A. Naseer ◽  
K. Marimuthu
Keyword(s):  
Borophosphate Glasses ◽  
Co Doping ◽  
The Impact

scholarly journals Nanophosphors-Based White Light Sources

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1048 ◽  
Author(s):  
Maura Cesaria ◽  
Baldassare Di Bartolo
Keyword(s):  
Rare Earth ◽  
White Light ◽  
Volume Ratio ◽  
Light Sources ◽  
Co Doping ◽  
New Class ◽  
Luminescence Efficiency ◽  
Metal Doped ◽  
The Individual ◽  
The Impact

Miniaturization requests and progress in nanofabrication are prompting worldwide interest in nanophosphors as white-emission mercury-free lighting sources. By comparison with their bulk counterparts, nanophosphors exhibit reduced concentration quenching effects and a great potential to enhance luminescence efficiency and tunability. In this paper, the physics of the nanophoshors is overviewed with a focus on the impact of spatial confinement and surface-to-volume ratio on the luminescence issue, as well as rare earth-activated multicolor emission for white light (WL) output. In this respect, the prominently practiced strategies to achieve WL emission are single nanophosphors directly yielding WL by means of co-doping and superposition of the individual red, green, and blue emissions from different nanophosphors. Recently, a new class of efficient broadband WL emitting nanophosphors has been proposed, i.e., nominally un-doped rare earth free oxide (yttrium oxide, Y2O3) nanopowders and Cr transition metal-doped garnet nanocrystals. In regard to this unconventional WL emission, the main points are: it is strictly a nanoscale phenomenon, the presence of an emitting center may favor WL emission without being necessary for observing it, and, its inherent origin is still unknown. A comparison between such an unconventional WL emission and the existing literature is presented to point out its novelty and superior lighting performances.

SYNTHESIS AND CHARACTERIZATION OF NANOCRYSTALLINE Co-DOPED ZnO THIN FILMS PREPARED BY CHEMICAL SPRAY PYROLYSIS FOR OPTOELECTRONIC APPLICATIONS

2021 ◽  
Author(s):  
FAEZ M. HASSAN ◽  
AUS A. NAJIM
Keyword(s):  
Thin Films ◽  
Spray Pyrolysis ◽  
Doping Concentration ◽  
Chemical Spray Pyrolysis ◽  
Co Doping ◽  
Glass Substrates ◽  
Chemical Spray ◽  
Good Transparency ◽  
The Impact ◽  
Co Doped

ZnO:Co thin films were synthesized by the chemical spray pyrolysis (CSP) on glass substrates. Then, investigated the impact of Co doping concentration on its physical properties. XRD analyses show that all films have a polycrystalline structure of hexagonal ZnO. The crystallite size increased from 18[Formula: see text]nm to 25[Formula: see text]nm with Co doping concentrations. Furthermore, the unit cell volume increased from 47.485[Formula: see text]Å to 47.831[Formula: see text]Å, and the Zn–O bond length expanded from 1.97588[Formula: see text]Å to 1.98071[Formula: see text]Å. SEM observations reveal the formation of fiber-like nanostructures in the Co-doped thin films. The diameter of nanofibers increased with Co doping concentration from 260[Formula: see text]nm to 700[Formula: see text]nm. The optical characteristics were studied by the UV-Visible spectrophotometer and manifest the optical transparency vary with Co doping. In addition, the band gap decreases from 3.27[Formula: see text]eV to 2.73[Formula: see text]eV with increasing Co doping concentrations. The conductivity varied from 3.35[Formula: see text]S[Formula: see text][Formula: see text][Formula: see text]m[Formula: see text] to 19.88[Formula: see text]S[Formula: see text][Formula: see text][Formula: see text]m[Formula: see text] with Co doping concentrations. Empirical models were proposed to evaluate the correlated variables with excellent accuracy with the experimental data. The best result was accomplished in ZnO:Co1% films, where good transparency and high conductivity were achieved.

scholarly journals Synergistic effect of trivalent (Gd3+, Sm3+) and high-valent (Ti4+) co-doping on antiferromagnetic YFeO3

RSC Advances ◽  
2020 ◽  
Vol 10 (37) ◽  
pp. 22183-22195 ◽  
Author(s):  
P. S. J. Bharadwaj ◽  
Swarup Kundu ◽  
Vijay Sai Kollipara ◽  
Kalidindi B. R. Varma
Keyword(s):  
Magnetic Properties ◽  
Synergistic Effect ◽  
Co Doping ◽  
Optical And Magnetic Properties ◽  
High Valent ◽  
The Impact

The work investigates the impact of doping (Sm3+, Gd3+ at Y3+ site and Ti4+ at Fe3+ site respectively) on structural, optical and magnetic properties of YFeO3.

Impact of Doping of Bi3+ on Luminescent Properties of Red Phosphors Sr3-xGaO4F:xEu3+

2015 ◽  
Vol 1120-1121 ◽  
pp. 401-405
Author(s):  
Rong Ying Liu ◽  
Yuan Zhang Feng ◽  
Zi Fei Peng
Keyword(s):  
Energy Transition ◽  
Luminescent Properties ◽  
Solid State Reaction Method ◽  
Emission Peak ◽  
Doping Amount ◽  
Co Doping ◽  
Red Phosphors ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

It has been studied that the impact of doping of Bi3+on the luminescent properties of red phosphors Sr3-xGaO4F:xEu3+prepared with high temperature solid-state reaction method followed by doping into certain amounts of Bi2O3. The resulting samples are characterized by XRD, Emission Spectrum and Excitation Spectrum. As a result, it is shown that the strongest emission peak caused by the forced electronic dipole transition of5D0-7F2is at 618 nm with solely doping of Eu3+. In addition, the luminescent intensity of the as-formed phosphor increases and the most intensive emission peak red-shifts with doping amount of Bi3+while co-doping Eu3+and Bi3+. Meanwhile, the relationship of energy transition of Eu3+and Bi3+is also discussed herein.

Impact of the Co Doping on the Structure, Magnetic Properties, and Phase Transition in Ni50-xCoxMn38Sn12 Ribbons

2021 ◽  
Vol 1035 ◽  
pp. 698-703
Author(s):  
Tarek Bachagha ◽  
Long Hou ◽  
Guan Hua Qin ◽  
Xi Li ◽  
Chao Jing ◽  
...  
Keyword(s):  
Phase Transition ◽  
Magnetic Properties ◽  
Heusler Alloys ◽  
Cobalt Content ◽  
Martensitic Transition ◽  
Co Doping ◽  
Sample Structure ◽  
Enthalpy And Entropy ◽  
The Impact ◽  
Magnetization Change

Three Heusler alloys, Ni50-xCoxMn38Sn12 (x = 1, 2, and 3), were elaborated by rapid solidification. The impact of the Co doping on the structure, magnetic properties, and phase transition in these alloys was studied. The structure of the Ni49Co1Mn38Sn12 and Ni48Co2Mn38Sn12 ribbons was martensite 14M monoclinic structure, while the Ni47Co3Mn38Sn12 sample structure was austenite cubic L21. The thermal analysis showed the impact of the substitution Ni by Co. It was noted that the temperatures of martensitic transition moved lower, and a decreases progressively of enthalpy and entropy changed. Likewise, an obvious increase in the temperature of Curie transition for austenite phase (TAC) was observed and a jump of magnetization change (ΔM) was detected, with increasing Cobalt content.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

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