Layered Yttrium Research Articles

Synthesis of Y2O3:Bi3+,Yb3+ nanosheets from layered yttrium hydroxide precursor and their photoluminescence properties

Morphologies, photoluminescence properties, and photostability were characterized for Y2O3:Bi3+,Yb3+ fluorescent nanosheets prepared through calcining solvothermally synthesized layered yttrium hydroxide precursors.

Synthesis of Y2O3:Bi3+,Eu3+ nanosheets from layered yttrium hydroxide precursor and their photoluminescence properties

Morphologies, photoluminescence properties, and photostability were characterized for Y2O3:Bi3+,Eu3+ fluorescent nanosheets prepared through calcining solvothermally synthesized layered yttrium hydroxide precursors.

Preparation of Layered Yttrium Oxide by Hydrolysis of Yttrium Nitrate

Hydrolysis products of aqueous yttrium nitrates obtained by sol-gel method at room temperature, under atmospheric pressure without any templates and structure directing agents were investigated by thermal analysis combined with mass spectrometry of thermolysis products, XRD and scanning electron microscope with elemental EDS analyzer. Formation of yttrium hydroxonitrocarbonates with various ratio depending on synthesis conditions was found. The samples obtained at 8.5 pH with hydrolysis time at least 40 min using ammonia water solution have the least quantity of impurities and demonstrates the most visible layered morphology. The most explicit layered morphology and the least amount of impurities were revealed in the samples obtained at 8.5 pH with hydrolysis time at least 40 min using ammonia water solution as a hydrolytic agent.

Fast synthesis of β-NaYF4:Ln3+(Ln = Yb/Er, Yb/Tm) upconversion nanocrystals via a topotactic transformation route

Monodisperse β-NaYF4:Ln3+ (Ln = Yb/Er, Yb/Tm) upconversion nanocrystals have been fast synthesized using layered yttrium hydroxide Y2(OH)5NO3·nH2O (LYH) via a topotactic transformation route bypassing the α-NaYF4 intermediate phase. It was found that the topotactic structural matching of [001]LYH//[0001]β-NaYF4 facilitated the direct formation of β-NaYF4, wherein the kinetic α-NaYF4 intermediate phase could be avoided at the initial reaction stage. Besides, the morphology could be effectively tuned by manipulating the NaF/Y(NO3)3 feeding ratio. In addition, the upconversion luminescence properties of the as-prepared β-NaYF4:15%Yb3+/2%Er3+ and β-NaYF4:15%Yb3+/1%Tm3+ were also systematically investigated.

Synthesis of a peroxo derivative of layered yttrium hydroxide

A stable yttrium peroxo compound containing 6.7% active (peroxide) oxygen is prepared by reacting layered yttrium hydroxonitrate Y4(OH)10(NO3)2 · xH2O with 12% or 87% aq. H2O2 at 0°C. The active oxygen in this compound is in the form of HO 2 - - and O 2 2- - groups as probed by IR and Raman spectroscopy. The thermolysis of the yttrium peroxo compound yields nanosized (6 nm) yttrium oxide.

High-yield microwave synthesis of layered Y2(OH)5NO3·xH2O materials

A novel, facile, and versatile microwave-assisted method of high-yield synthesis of layered rare earth hydroxo compounds (LRHs) is proposed. Layered yttrium hydroxonitrates synthesized by the microwave-assisted technique crystallize in the form of thin hexagonal plates aggregated into spheroidal particles. Depending on the conditions of microwave-assisted hydrothermal synthesis, the formation of several phases differing in interplanar spacing along the [00l] direction is possible. The materials obtained are shown to possess good anion-exchange properties. This work provides a route to large-scale synthesis of LRH-based advanced materials.

The inner filter effect of Cr(VI) on Tb-doped layered rare earth hydroxychlorides: new fluorescent adsorbents for the simple detection of Cr(VI).

Terbium-doped layered yttrium hydroxychlorides (LYH:xTb) were explored for the simple and convenient detection of Cr(VI) in aqueous solution, where the effective overlap of excitation bands of LYH:xTb with absorption bands of Cr(VI) constructs a new inner filter effect system. The shielding of excitation light for LYH:xTb by adsorbed Cr(VI) was so effective that a feasible detection sensitivity could be achieved.

One-step synthesis of layered yttrium hydroxides in immiscible liquid–liquid systems: Intercalation of sterically-bulky hydrophobic organic anions and doping of europium ions

Inorganic–organic layered rare-earth compounds were synthesized on the basis of a biphasic liquid–liquid system in one pot. Layered yttrium hydroxides (LYHs) were chosen as a host material for the intercalation of hydrophobic organic guest anions such as benzoate, sebacate, or laurate. In a typical synthesis, an organic phase dissolving carboxylic acid was placed in contact with an equal amount of an aqueous phase dissolving yttrium nitrate n-hydrate and urea. At elevated temperatures up to 80°C, urea was hydrolyzed to release hydroxyl anions which were used to form yttrium hydroxide layers. LYHs were then precipitated with the intercalation of carboxylate anions delivered from the organic phase under the distribution law. The structure and the morphology of the LYHs could be modulated by the intercalated anions. Doped with Eu3+ ions, the LYHs exhibited red photoluminescence which was enhanced by the intercalated anions due to the antenna effect.

The selective antenna effect of tungstate anions for Tb-doped layered yttrium hydroxynitrate

A simple way to detect and remove trace amounts of WO4(2-) ions from an aqueous solution was demonstrated by their light-harvesting ability and selective excitation energy transfer to a Tb-doped layered yttrium hydroxynitrate matrix.

Hybrid of Europium‐Doped Layered Yttrium Hydroxide and Organic Sensitizer – Effect of Solvent on Structure and Luminescence Behavior

AbstractThe organic sensitizer terephthalic acid and its anion terephthalate (TA) were introduced into the galleries of europium‐doped layered yttrium hydroxide (LYH:Eu). In contrast to using water as solvent, the use of formamide resulted in the introduction of more organic guests and markedly enhanced the Eu3+ luminescence. Formamide prevented water from entering the system, leading to an excess of terephthalic acid molecules, and more efficient coordination of the TA guest with the Eu3+ in the layers of the composite, all of which may have contributed to the enhanced Eu3+ luminescence.

Synthesis of Highly Luminescent and Anion-Exchangeable Cerium-Doped Layered Yttrium Hydroxides for Sensing and Photofunctional Applications

The discovery of new lanthanide properties in layered rare-earth hydroxides is tremendously important to developing novel materials with the advantages of both lanthanides and layered hydroxides. Herein, a polyethylenimine-assisted hydrothermal route for preparing Ce-doped layered yttrium hydroxide nanoplates (LYH:Ce NPs) is established, in which the Ce doping provides simultaneous control of the size and fluorescent properties. Typically, 10% Ce doping tailors the average particle size from 680 to 196 nm and induces bright blue luminescence with a quantum efficiency of over 10.0%. Owing to the much more efficient f–d Ce3+ transition, the LYH:Ce NPs show three orders of magnitude stronger photoluminescence than LYH:Eu and LYH:Tb NPs, and exhibit the properties required to fabricate switched “on/off” optical sensors by controlling the Ce3+ Ce4+ redox couple. Furthermore, by combining the merits of the luminescence of Ce3+ dopants and anion-exchange ability of an LYH host, the LYH:Ce NPs exhibit the properties necessary for photofunctional materials for photosensitized singlet oxygen production.

Intercalation of Ethylene Glycol into Yttrium Hydroxide Layered Materials

Intercalation of ethylene glycol into layered yttrium hydroxide containing nitrate counterions was accomplished by heating the reagents in a methanol solution of sodium methoxide under autogenous pressure at 413 K for 20 h. The resulting crystalline material had an expanded interlayer distance of 10.96 A, confirming the intercalation of an ethylene glycol derived species. Characterization of the material by FT-IR spectroscopy, thermogravimetric analysis, and the catalytic transesterification of tributyrin with methanol was consistent with direct bonding of ethylene glycolate anions (O(2)C(2)H(5)(-)) to the yttrium hydroxide layers, forming Y-O-C bonds. The layers of the material are proposed to be held together by H-bonding between the hydroxyls of grafted ethylene glycol molecules attached to adjacent layers. Glycerol can also be intercalated into yttrium hydroxide layered materials by a similar method.

Exfoliation and Stable Suspension of Layered Yttrium Hydroxide in Toluene

Exfoliation and Stable Suspension of Layered Yttrium Hydroxide in Toluene

Exfoliation and Stable Suspension of Layered Yttrium Hydroxide in Toluene.

Exfoliation and Stable Suspension of Layered Yttrium Hydroxide in Toluene.

Existence region, structure, and properties of YBa(Cu1−x Fex)2O5+δ and (Y1−y Ba y )2 CuFeO5+δ solid solutions

We study the effect of Y3+ ↔ Ba2+ and Cu2+ ↔ Fe3+ substitutions on the structure, thermal expansion, electrical conductivity, and thermal e.m.f. of layered ferrocuprate YBaCuFeO5 + δ · YBa(Cu1−xFex)2O5 + δ solid solutions with 0.45≤x≤0.55 are formed. The unit cell parameters, thermal expansivity, and oxygen nonstoichiometry index of the YBaCuFeO5 +δ phase (δ) are almost independent of variations in the cationic composition of this phase. The electrical conductivity of layered yttrium barium ferrocuprate increases, whereas the activation energy of conductivity decreases in response to Ba2+ → Y3+ and Cu2+ → Fe3+ substitutions (with increasing copper(III) proportion in samples). The thermal e.m.f. of ceramics decreases when composition deviates from the cationic stoichiometry (YBaCuFeO5 +δ).

Resonance Magnetoelectric Effect in Multilayer Composites

The phenomenological theory is presented on the influence of external electric field on the shift of resonance magnetic field, magnetic and magnetoelectric (ME) susceptibilities of composites. The shift of resonance magnetic field is proportional to linear and bilinear ME constants. The concentration and electric field dependencies of magnetic resonance field shift for layered nickel ferrite, lithium ferrite and yttrium iron garnet with ferroelectric lead zirconate titanate are calculated. Three measurement methods of ME susceptibility using resonant ME connection, electrical dipole transitions and resonant ME effect are proposed. The method of electrical dipole transitions is investigated in detail. Expressions for linear and bilinear ME susceptibility of the composite (symmetry point group 3 m or 4 mm) at high frequencies are found. The results of ME susceptibility measurement are useful for the analysis of electrically controlled high frequency devices of magnetic type, such as phase shifters, attenuators, and filters.

The rare-earth metal carbide halide superconductors RE 2C 2X 2 (RE=Y, La; X=Cl, Br, I)

Superconductivity in layered yttrium carbide bromides and iodides with transition temperatures ranging up to 11.6 K is achieved by adjusting the Br:I, ratio to ≈1:3 in phases of Y 2C 2(Br,I) 2. In our contribution, we compile basic physical and chemical properties of Y 2C 2X 2 (X=Cl, Br, I) and present new results of the La-based phases La 2C 2X 2 (X=Br, I).

Effect of higher order magnetostatic forward volume wave modes on Bragg diffraction of laser light in a layered yttrium iron garnet film geometry

The present article reports a theoretical study of the TM0⇥TE0 mode conversion of laser light through Bragg diffraction by higher order magnetostatic forward volume waves (MSFVWs) in a layered yttrium iron garnet (YIG) film geometry. It is found that this mode conversion can be significant, thereby somewhat mitigating the previously reported advantage of YIG film layering, i.e., layering affords a significant improvement in the bandwidth for magneto-optic coupling. Computations of the level of magneto-optic (MO) coupling caused by higher order MSFVWs excited by a microstrip transducer in a double YIG film layered structure are presented. The use of a triple YIG film layered geometry with lifted transducers for suppressing the unwanted effect of higher order MSFVW modes on the MO coupling is discussed.

ChemInform Abstract: Preparation and Characterization of a New Layered Yttrium Nickel Borocarbide.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The preparation and characterization of a new layered yttrium nickel borocarbide

A new layered borocarbide with nominal composition of Y 2NiBC 2 has been prepared. The lattice constants a p = 3.570(1) A ̊ and c p = 13.064(5) A ̊ based on a primitive unit cell were obtained from least-squares fitting of the strong X-ray diffraction peaks. However, the actual cell dimensions were found to be a = √5 a p, c = 2 c p from the electron diffraction patterns. The structure of the compound can be viewed as an intergrowth of Ni 2B 2 and quadruple YC rock salt layers. A.c. susceptibility measurements showed that the samples were non-superconducting down to 4.2 K.