Inorganic pigments based on fluorite-type oxynitrides

2006 ◽  
Vol 21 (6) ◽  
pp. 1427-1433 ◽  
Author(s):  
M. Pérez-Estébanez ◽  
R. Pastrana-Fábregas ◽  
J. Isasi-Marín ◽  
R. Sáez-Puche
Keyword(s):  
Rare Earth ◽  
Fluorite Structure ◽  
Rare Earth Doping ◽  
Inorganic Pigments ◽  
Doping Amount ◽  
Cubic Symmetry ◽  
Fluorite Type ◽  
Cie Lab ◽  
Symmetry Space ◽  
Rare Earth Doped

Zirconia oxynitride rare-earth-doped pigments were prepared by ammonolysis of the zirconium rare-earth oxides, previously synthesized using the citrate complexation/calcination route. Different coloration has been obtained, the intensity of which is a function of the nitrogen amount in the case of the oxynitrides; in the case of the oxides, both color and intensity depend on the doping amount of rare earth. The obtained phases, Zr(1−x)CexO2, Zr(1−x)RxO(2−x/2)□x/2, with R = Eu or Er and Zr(1−x)RxO(2−x/2−3/2y)Ny□x/2■y/2 (R = Ce, Eu, and Er), have been characterized by x-ray powder diffraction, scanning electron microscopy, and reflectance spectra data. These results show that the phases with minor rare-earth concentration adopt a baddeleyite-type structure, with a monoclinic symmetry, space group P21/c. By increasing the rare-earth doping, the obtained phases crystallize with the fluorite structure with tetragonal (P42/nmc) or cubic symmetry (Fm¯3m). On the other hand, the study of the magnetic properties of the oxides and oxynitrides indicate a paramagnetic behavior, and in the case of the cerium oxide, the nitridation process produces the reduction from Ce4+ to Ce3+. Diffuse reflectance data and CIE-LAB color coordinates suggest that these ceramics based on nitrogen containing zirconia are expected to be promising candidates as new ecological inorganic pigments.

Rare-Earth-Doped Pt/Ba/Ce0.6Zr0.4O2-Al2O3for NOxStorage and Reduction: The Effect of Rare-Earth Doping on Efficiency and Stability

ChemCatChem ◽  
2013 ◽  
Vol 6 (1) ◽  
pp. 237-244 ◽  
Author(s):  
Xiuyun Wang ◽  
Zhilin Chen ◽  
Yuling Wang ◽  
Ruihu Wang
Keyword(s):  
Rare Earth ◽  
Rare Earth Doping ◽  
Rare Earth Doped

Elektroneutrale Pb4O4 -Heterokubaneinheiten in den Aluminatsodalithen Ln4[Al12O24](Pb4O4)2 (Ln = Nd, Sm) / Electrically Neutral Pb4O4 Heterocubane Units in Aluminate Sodalites Ln4[Al12O24](Pb4O4)2 (Ln = Nd, Sm)

1997 ◽  
Vol 52 (4) ◽  
pp. 449-452 ◽  
Author(s):  
J.-P. Werner ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystals ◽  
Rare Earth Ions ◽  
Neutral Network ◽  
Cubic Symmetry ◽  
Space Group ◽  
Coordination Spheres ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of Ln4[Al12O24](Pb4O4)2 (Ln = Nd, Sm) have been prepared by flux techniques. The compounds crystallize with cubic symmetry, space group Oh-Pn3̄m, aNd = 9.514(1), aSm = 9.481(1) Å, Z = 1. The crystal structure is characterized by a [Al12O24]12- framework. Four of the eight six-membered rings of AlO4-tetrahedra per sodalite cage are centered by Ln3+ ions. The cages of the resulting electrically neutral network are filled with [Pb4O4]±0 heterocubane units. Oxygen of the heterocubane units completes the coordination spheres of the rare earth ions to hexagonal bipyramids.

Covering the optical spectrum through collective rare-earth doping of NaGdF4 nanoparticles: 806 and 980 nm excitation routes

2017 ◽  
Vol 19 (19) ◽  
pp. 11825-11834 ◽  
Author(s):  
A. Skripka ◽  
R. Marin ◽  
A. Benayas ◽  
P. Canton ◽  
E. Hemmer ◽  
...  
Keyword(s):  
Rare Earth ◽  
Optical Spectrum ◽  
Near Infrared ◽  
Rare Earth Doping ◽  
Rare Earth Doped

Sensitization of numerous emission bands (from ultraviolet to near-infrared) in rare-earth doped multilayered nanoparticles: 806 versus 980 nm excitation.

Preparation and Properties of Rare Earth-Doped TiO2 Thin Films by Sol-Gel Process

2014 ◽  
Vol 1033-1034 ◽  
pp. 1235-1238
Author(s):  
Tao Bai ◽  
Shi Gen Zhu
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Sol Gel ◽  
Rare Earth Doping ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Scanning Electronmicroscopy ◽  
Rare Earth Doped ◽  
The Rare Earth

Rare earth doped titaniumdioxide (TiO2) thin films (rare earth-doped TiO2) have been successfully prepared on a glass substrate by a sol–gel route. After the rare earth-doped TiO2thin films were calcined at 773K for 1h, the effect of rare earth-doping on the properties were investigated using X-ray diffraction (XRD), scanning electronmicroscopy (SEM), ultraviolet–visible spectroscopy and thermogravimetric techniques (TG/DTG). The XRD results showed that rare earth-doped TiO2thin films contained only a single crystalline phase of anatase TiO2after calcining at 773K for 1h. SEM micrographs showed that rare earth-doped TiO2thin films have smooth surfaces containing granular nanocrystallines and are without cracks. The UV–vis absorption spectra showed that the absorption of the rare earth-doped TiO2thin films has a red-shift. From ambient to 1273K, it is about 12% of mass loss because of the volatilizing of water and organic and the phase transformation.

The Study of Activity of Rare-Earth Doped Four Potassium Titanate Whiskers Composite Photocatalyst

2013 ◽  
Vol 798-799 ◽  
pp. 170-173
Author(s):  
Mao Bin Wei ◽  
Dan Dan Wang ◽  
Zi Yang Lu ◽  
Peng Wei Huo ◽  
Yong Sheng Yan
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Rare Earth ◽  
Degradation Rate ◽  
Treatment Temperature ◽  
Rare Earth Doping ◽  
Composite Photocatalyst ◽  
Potassium Titanate ◽  
Photodegradation Rate ◽  
Rare Earth Doped

In this paper, the high temperature was adopted to treat the composited photocatalysts. The effects of different heat treatment temperature, rare-earth and concentration rare-earth on photocatalytic activity were investigated. The results showed that the photocatalytic activity was better when potassium titanate whiskers were calcinated at 600 0C without rare-earth doping. The effect of potassium titanate whiskers doped neodymium ion was the best, the degradation rate could increase to 59.0%. When neodymium nitrate was 0.04g, the degradation rate of composites photocatalysts was the best. The photodegradation rate could reach 74.02%. And the degradation rate of 10 mg/L tetracycline at 20 0C could increase to 86.31%.

scholarly journals Effect of Rare-Earth Doping on the Structural and Optical Properties of the Ag3AsS3 Crystals

2021 ◽  
Author(s):  
O.V. Smitiukh ◽  
O.V. Marchuk ◽  
Y.M. Kogut ◽  
V.O. Yukhymchuk ◽  
N.V. Mazur ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rare Earth ◽  
Second Harmonic ◽  
Rare Earth Doping ◽  
Electromagnetic Spectrum ◽  
Non Linear ◽  
Nlo Materials ◽  
Linear Optical ◽  
Rare Earth Doped ◽  
The Rare Earth

Abstract Non-linear optical (NLO) materials allow the production of the coherent laser beam in the difficult frequency ranges of the electromagnetic spectrum. Aiming to explore new classes of the NLO materials with high optical performance in the infrared (IR) region, in this work, we investigated the effect of the rare earth doping (Pr, Eu, Yb) on the crystal structure and optical properties of the Ag3AsS3 crystals. The performed analysis of the XRD patterns indicates that the rare earth elements are located in the Ag sites of the crystal lattice. As a result, the second harmonic generation (SHG) intensity, which determines the effectiveness of the NLO materials, increases with the increase of rare earth dopant content up to 1.0 %. Using the absorption analysis and Raman spectroscopy, we show that the increase in the SHG intensity can be related to the slight decrease of the bandgap, as well as with the increased electron-phonon interaction in rare-earth-doped Ag3AsS3 crystals. Considering the discovered enhancement of the SHG intensity, accompanied by the low melting temperature, this work offers rare-earth-doped Ag3AsS3 crystals as potential candidates for the non-linear optical applications for the infrared frequency range.

Increased Refractive Indices in Rare Earth Doped InP and In0.53 Ga0.47 as Thin Films

1996 ◽  
Vol 422 ◽  
Author(s):  
B. J. H. Stadler ◽  
J. P. Lorenzo
Keyword(s):  
Refractive Index ◽  
Rare Earth ◽  
Lattice Parameter ◽  
Rare Earth Ions ◽  
Refractive Indices ◽  
Rare Earth Doping ◽  
Er Doping ◽  
Order Of Magnitude ◽  
Er Doped ◽  
Rare Earth Doped

AbstractRare earth (Gd, Eu, Er) doped InGaAs and InP layers were grown by liquid phase epitaxy (LPE). The refractive index of these layers was observed to increase with the addition of the rare earth ions. The observed increase could not be explained by changes in host composition as typically calculated from changes in lattice parameter. In fact, the refractive index was seen to increase (∼0.25) by an order of magnitude more than would be expected by the change in the lattice parameter (∼0.02). The increased refractive indices of InP layers due to Er-doping enabled waveguiding. These findings suggest that optically active waveguide devices can be fabricated from semiconducting hosts by simple rare earth doping.

Synthese und Kristallstruktur von Pb2LnAl3O8 (Ln = Eu, Gd) / Synthesis and Crystal Structure of Pb2LnAl3O8 (Ln = Eu, Gd)

1996 ◽  
Vol 51 (6) ◽  
pp. 883-887 ◽  
Author(s):  
J.-P. Werner ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystals ◽  
Rare Earth Ions ◽  
Synthesis And Crystal Structure ◽  
Cubic Symmetry ◽  
Space Group ◽  
Symmetry Space ◽  
Symmetry Space Group ◽  
The Rare Earth

Abstract Single Crystals of Pb2LnAl3O8 (Ln = Eu, Gd) have been prepared by flux techniques. The compounds crystallize with cubic symmetry, space group Oh-Pn3̅m, a(Eu) = 9.4578(5), a(Gd) = 9.4448(7) Å, Z = 4. The crystal structure is characterized by heterocubane units of the type Pb4O4 and hexagonal bipyramids of oxygen around the rare earth ions. These components form a network made of macro polyhedra of the type Pb4O4- LnO6- Pb4O4

Effect of Rare-Earth Cation Doping on Enhancement of The Thermoelectric Power of Zinc Oxide

2005 ◽  
Vol 886 ◽  
Author(s):  
Kiyoshi Fuda ◽  
Shigeaki Sugiyama
Keyword(s):  
Rare Earth ◽  
Thermoelectric Power ◽  
Rare Earth Ions ◽  
Rare Earth Doping ◽  
Rare Earth Cation ◽  
Temperature Range ◽  
Seebeck Coefficients ◽  
Earth Cation ◽  
Doped Zno ◽  
Rare Earth Doped

ABSTRACTWe investigated the effects of doping of rare-earth ions (Ce, Pr, Nd, Sm, and Eu) on the thermoelectric properties of ZnO, especially Seebeck coefficient in the temperature range from 100 to 800 °C. The data were scattered more or less depending on the doping species, but it was commonly found that the rare-earth doped samples showed higher Seebeck coefficients with compared to those for Al-doped samples. The highest values were observed for Nd-doped one ranging from -360 to -400μVK−1 in the temperature range observed, the lowest ones for Pr-doped one ranging from -250 to -310 μVK−1, whereas those for Al-doped one ranging from -80 to -140 μVK−1. It should also be pointed out that the power factor at 100 °C for Pr-doped ZnO was twice or more as much as that for Al-doped one. From the results it seemed that rare earth doping is effective for enhancement of thermoelectric power of ZnO.

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