Spectroscopic properties of CrOx/Al2O3 nanopowders synthesized by cw CO2 laser vaporization

Abstract Nanosized 5.0 wt% Cr/nano-Al2O3 powders with the particle size of ca. 15 nm were synthesized via laser vaporization using irradiation by a cw CO2 laser in different gas atmospheres – Ar, Ar+O2, Ar+H2. All the investigated nanopowders were studied by XRF, XRD, TEM, UV-vis DRS and PL spectroscopy methods. The nanopowders were found to contain the Cr6+ ions located on the surface of Al2O3 nanoparticles and two types of Cr3+ sites. One type is Cr3+ ions located in the bulk (Cr3+ b-sites) of Al2O3 matrix in a strong crystal field. The second type is represented by Cr3+ sites residing near the surface (Cr3+ s-sites) of CrOx/Al2O3 nanoparticles in a weak crystal field. It was shown that varying the composition of the buffer gas (Ar, Ar+O2, Ar+H2) during laser vaporization makes it possible to control the properties of the obtained 5.0 wt% Cr/nano-Al2O3 nanopowders with a change in Cr6+/Cr3+ ratio in the bulk and on the surface of alumina support.

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Size-dependent photoluminescence of europium in alumina nanoparticles synthesized by cw CO2 laser vaporization

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2019.152476 ◽

2020 ◽

Vol 815 ◽

pp. 152476 ◽

Cited By ~ 1

Author(s):

Anton I. Kostyukov ◽

Vladimir N. Snytnikov ◽

Aleksey V. Zhuzhgov ◽

Svetlana V. Cherepanova ◽

Arcady V. Ishchenko ◽

...

Keyword(s):

Co2 Laser ◽

Alumina Nanoparticles ◽

Laser Vaporization ◽

Size Dependent ◽

Cw Co2 Laser

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Luminescent properties of Al2O3:Tb3+ nanoparticles obtained by cw CO2 laser vaporization

Optical Materials ◽

10.1016/j.optmat.2020.110508 ◽

2020 ◽

Vol 110 ◽

pp. 110508

Author(s):

Anton I. Kostyukov ◽

Vladimir N. Snytnikov ◽

Marianna I. Rakhmanova ◽

Nadezhda Y. Kostyukova ◽

Valeriy N. Snytnikov

Keyword(s):

Co2 Laser ◽

Luminescent Properties ◽

Laser Vaporization ◽

Cw Co2 Laser

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Synthesis, structure and photoluminescent properties of Eu:Gd2O3 nanophosphor synthesized by cw CO2 laser vaporization

Journal of Luminescence ◽

10.1016/j.jlumin.2021.118050 ◽

2021 ◽

pp. 118050

Author(s):

Anton I. Kostyukov ◽

Valeriy N. Snytnikov ◽

Vladimir N. Snytnikov ◽

Marianna I. Rakhmanova ◽

Nadezhda Y. Kostyukova ◽

...

Keyword(s):

Co2 Laser ◽

Laser Vaporization ◽

Cw Co2 Laser

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Investigations on cw CO2-laser induced welding plasmas using differential interferometry

10.2351/1.5059248 ◽

1999 ◽

Cited By ~ 1

Author(s):

Henrik Schittenhelm ◽

Jürgen Müller ◽

Peter Berger ◽

Helmut Hügel

Keyword(s):

Co2 Laser ◽

Differential Interferometry ◽

Cw Co2 Laser

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Spatial temperature distribution in CW CO2 laser photosensitized reactions

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19841354 ◽

1984 ◽

Vol 49 (6) ◽

pp. 1354-1359 ◽

Cited By ~ 1

Author(s):

Pavel Kubát ◽

Josef Pola

Keyword(s):

Temperature Distribution ◽

Chemical Reactions ◽

Co2 Laser ◽

Computational Procedure ◽

Heat Convection ◽

Inert Gas ◽

Spatial Temperature Distribution ◽

Cw Co2 Laser ◽

Spatial Temperature

The temperature distribution in gaseous SF6 and SF6-inert gas samples under irradiation with cw CO2 laser measured by a thermocouple technique is confronted with the results of a computational procedure neglecting heat convection. The results are helpful in understanding the effect of the inert gas on the distribution of temperature and the size of the reacting hot volume in the cw laser-photosensitized chemical reactions.

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Cw CO2 laser driven oxidation of some perhalogenocycloalkenes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19910398 ◽

1991 ◽

Vol 56 (2) ◽

pp. 398-405 ◽

Cited By ~ 2

Author(s):

Josef Pola ◽

Jaroslav Včelák ◽

Zdeněk Chvátal

Keyword(s):

Co2 Laser ◽

Total Pressure ◽

Diels Alder ◽

Title Reaction ◽

Consecutive Reactions ◽

Cw Co2 Laser

The title reaction of hexafluorocyclobutene, 1,2-dichloro-3,3,4,4-tetrafluorocyclobutene and decafluorocyclohexene studied at total pressure 13.3 and 16 kPa yield oxalyl halides COX.COX (X = F, Cl) and C2F4 that undergo consecutive reactions to COF2, CO and X2. The oxidation of decafluorocyclohexene is preceded by retro-Diels-Alder decomposition affording hexafluorocyclobutene and C2F4. Two alternative mechanisms for the oxidation of the cyclobutenes are presented, one involving a novel cleavage of intermediary bicyclic dioxetanes. The decomposition of oxalyl fluoride into COF2 and CO is favored over its oxidation.

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Influence of a radial inhomogeneity of the active medium on the output radiation power from a cw CO2 laser with fast axial flow

10.1117/12.262912 ◽

1996 ◽

Author(s):

Michail G. Galushkin ◽

Vladimir S. Golubev ◽

V. V. Dembovetsky ◽

Yuri N. Zavalov ◽

Valentina Y. Zavalova

Keyword(s):

Active Medium ◽

Co2 Laser ◽

Radiation Power ◽

Axial Flow ◽

Output Radiation ◽

Radial Inhomogeneity ◽

Cw Co2 Laser ◽

Output Radiation Power

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Tuning morphology, surface, and nanocrystallinity of rare earth vanadates by one-pot colloidal conversion of hydroxycarbonates

Nanoscale ◽

10.1039/d0nr07902b ◽

2021 ◽

Author(s):

Gabriela Guida ◽

Steven Huband ◽

Marc Walker ◽

Richard I. Walton ◽

Paulo C. de Sousa Filho

Keyword(s):

Particle Size ◽

Rare Earth ◽

Defect Density ◽

Spectroscopic Properties ◽

One Pot

The mechanisms of a one-pot colloidal conversion of hydroxycarbonate templates into vanadate nanoparticles were investigated, with further correlation of Eu3+ spectroscopic properties to particle size, texture, nanocrystallinity, and defect density.

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