Fine structural photoluminescence spectra of silica-supported zirconium oxide and its photoactivity in direct methane conversion

2002 ◽  
pp. 2014-2015 ◽  
Author(s):  
Hisao Yoshida ◽  
Manohar G. Chaskar ◽  
Yuko Kato ◽  
Tadashi Hattori
Keyword(s):  
Methane Conversion ◽  
Zirconium Oxide ◽  
Photoluminescence Spectra

scholarly journals Оптические свойства кристаллов (ZrO-=SUB=-2-=/SUB=-)-=SUB=-1-x-=/SUB=-(Y-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-)-=SUB=-x-=/SUB=- (x=0-0.037), полученных направленной кристаллизацией расплава

2020 ◽  
Vol 128 (12) ◽  
pp. 1830
Author(s):  
Т.В. Перевалов ◽  
В.Н. Кручинин ◽  
С.В. Рыхлицкий ◽  
В.А. Гриценко ◽  
А.П. Елисеев ◽  
...  
Keyword(s):  
Zirconium Oxide ◽  
Oxygen Vacancies ◽  
Maximum Energy ◽  
Photoluminescence Spectra ◽  
High Concentration ◽  
Green Luminescence ◽  
Monoclinic Zro2 ◽  
Tetragonal Modification ◽  
Properties Of Materials ◽  
Optical Properties Of Materials

The luminescent and optical properties of materials based on zirconium oxide obtained by the crystallization of ZrO2 with 0, 2.0, 2.5, 2.8, and 3.7% mol Y2O3 melts were studied. Using Raman spectroscopy, it was found that when the Y2O3 content in the mixture is less than 2 % mol. the material is predominantly a monoclinic ZrO2 structure. For such crystal, a blue-green band with the maximum energy of 2.4 eV was observed in the photoluminescence spectra. This fact, together with the peculiarities of the refractive index and absorption dispersion spectra, indicates the presence of a high concentration of oxygen vacancies and polyvacancies in the sample. With a higher content of Y2O3 in the mixture, the tetragonal modification of ZrO2 dominates in the studied materials; the intensity of blue-green luminescence decreases. A comparative analysis of experimental optical spectra with the first-principle calculations for ideal ZrO2 crystals in the cubic, tetragonal and monoclinic phases was performed.

scholarly journals Photoluminescence in ZrO2 doped with Y and La

Cerâmica ◽  
2007 ◽  
Vol 53 (325) ◽  
pp. 99-103 ◽  
Author(s):  
W. S. C. de Sousa ◽  
D. M. A. Melo ◽  
J. E. C. da Silva ◽  
R. S. Nasar ◽  
M. C. Nasar ◽  
...  
Keyword(s):  
Solid Solution ◽  
Phase Formation ◽  
Zirconium Oxide ◽  
Yttrium Nitrate ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Oxide Solid Solution

This study aims to describe the synthesis and optical characterization of a nanometric zirconium oxide solid solution containing yttrium and lanthanum. Zirconium citrate, yttrium nitrate and lanthanum nitrate were mixed in the ratios: 94 mol% of ZrO2 - 6 mol% of Y2O3 and 92 mol% of ZrO2 - 6 mol % of Y2O3 - 2 mol % of La2O3. FTIR analysis shows organic material in decomposition and thermal analysis shows the transformation from the tetragonal to the monoclinic phase of zirconia, the loss of water molecule and zirconium dehydroxylation. The X-ray diffraction analysis shows a homogeneous phase formation of ZrO2-Y2O3-La2O3 demonstrating that lanthanum addition does not cause phase formation, promoting a solid solution based on zirconia with cubic structure. The photoluminescence spectra show absorption bands at 562 nm and 572 nm (350 °C) and specific absorption bands at 543 nm, 561 nm, 614 nm and 641 nm (900 °C). The photoluminescence effect at low temperature is caused by defects such as (Y Zr,Y O)', (2Y Zr,V O)'' and V O. Emissions at 614 nm and 641 nm are caused by O-2p -> Zr-4d transition. An emission at 543 nm can be attributed to LaO8 centers with O-2p -> La-5d transition.

Resolving Crystallites in Zirconium Oxide Films

1969 ◽  
Vol 27 ◽  
pp. 140-141
Author(s):  
R.A. Ploc
Keyword(s):  
Electron Microscope ◽  
Inelastic Scattering ◽  
Zirconium Oxide ◽  
Oxide Films ◽  
Optic Axis ◽  
Objective Lens ◽  
Microscope Objective ◽  
Linear Optic ◽  
A Current ◽  
Microscope Objective Lens

The optic axis of an electron microscope objective lens is usually assumed to be straight and co-linear with the mechanical center. No reason exists to assume such perfection and, indeed, simple reasoning suggests that it is a complicated curve. A current centered objective lens with a non-linear optic axis when used in conjunction with other lenses, leads to serious image errors if the nature of the specimen is such as to produce intense inelastic scattering.

ZIRCAR ZIRCONIA POWDER TYPE ZYP-4.5

Alloy Digest ◽  
1989 ◽  
Vol 38 (3) ◽  
Keyword(s):  
Fracture Toughness ◽  
Physical Properties ◽  
Yttrium Oxide ◽  
Zirconium Oxide ◽  
Raw Material ◽  
Bend Strength ◽  
Powder Metal ◽  
Zirconia Powder ◽  
Tetragonal Crystal ◽  
Powder Type

Abstract ZIRCAR ZIRCONIA POWDER TYPEZYP-4.5 is a highly reactive form of zirconium oxide stabilized in the tetragonal crystal state with added yttrium oxide. It is an excellent raw material for producing dense structural and wear resistant parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and bend strength as well as fracture toughness. It also includes information on powder metal forms. Filing Code: Cer-1. Producer or source: Zircar Products Inc..

Oxygen Vacancies in Zirconium Oxide as the Blue Luminescence Centers and Traps Responsible for Charge Transport

2020 ◽  
Author(s):  
Damir R. Islamov ◽  
Vladimir A. Gritsenko ◽  
Timofey V. Perevalov ◽  
Vladimir Sh. Aliev ◽  
Alexander P. Yelisseyev ◽  
...  
Keyword(s):  
Charge Transport ◽  
Zirconium Oxide ◽  
Oxygen Vacancies ◽  
Blue Luminescence ◽  
Luminescence Centers
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