Ytterbium Oxide Research Articles

Green synthesis of Ionic liquid mediated Ytterbium oxide nanoparticles by Andrographis Paniculata leaves extract for structural, morphological and biomedical applications

The eco-friendly synthesis of Yb2O3 and IL-Yb2O3 NPs was performed by Andrographis Paniculata leaves extract. The XRD pattern described the crystalline behavior and the crystallite size was at 50 and 45 nm for Yb2O3 and IL-Yb2O3 NPs. The FTIR and Raman analyses illustrated the functional groups of Yb2O3 and IL-Yb2O3 NPs. The UV–visible analysis described the formation of synthesized NPs with the absorption peak at 227 and 239 nm. The photoluminescence study revealed the yellow color luminescent behavior of Yb2O3 and IL-Yb2O3 NPs. The formation of IL-Yb2O3 NPs with 25–75 nm particle size was revealed from DLS analysis. The SEM analysis explained the circular and rectangular morphology of Yb2O3 and IL-Yb2O3 NPs. The composition analysis of EDX showed the purity of Yb2O3 and IL-Yb2O3 NPs with the presence of only Yb and O peaks and also chemical elements of IL-Yb2O3 NPs was confirmed by XPS analysis. The HRTEM analysis explained the hexagonal structured formation of Yb2O3 and IL-Yb2O3 NPs. The antibacterial assay described the high inhibition of Yb2O3 and IL-Yb2O3 NPs on E.coli and S.aureus bacteria. The anti-diabetic assay revealed the biomedical behavior of Yb2O3 and IL-Yb2O3 NPs on α-Amylase. The anti-inflammatory assay found the potential denaturation of bovine serum albumin (BSA) by Yb2O3 and IL-Yb2O3 NPs. The antioxidant assay revealed the potential free radical scavenging behavior of Yb2O3 and IL-Yb2O3 NPs. The MTT assay found the biomedical potential action of Yb2O3 and IL-Yb2O3 NPs on the MCF-7 cancer cell line.

Electrical Conductivity, Liquidus Temperatures and Raman Spectra of YbCl3–KCl–Yb2O3 and YbCl3–KCl–NaCl–Yb2O3 Systems

The electrical conductivity of 0.507KCl–0.493YbCl3 and 0.5YbCl3–0.25KCl–0.25NaCl chloride melts with the ytterbium oxide (Yb2O3) additions ranging from 0 to 3.15 mol% was measured depending on both the temperature and concentration of Yb2O3. The liquidus temperatures of the studied systems containing from 0 to 3.35 mol.% Yb2O3 were determined by DSC method and the electrical conductivity measurements. The Yb2O3 additions increase the liquidus temperatures of the systems under study. The high-temperature Raman spectra of chloride (YbCl3–KCl–NaCl) and oxide-chloride (YbCl3–KCl–NaCl–Yb2O3) melts were recorded. In the oxide-chloride melt an additional band was detected in the region of 460 cm−1 corresponding to stretching-vibrations of the Yb–O bond in [OYb3Cln] oxychloride associates. There was no evidence of vibrational bands related to ytterbium oxide. Such changes in the Raman spectrum points to the dissociation of ytterbium oxide and modifications to the local structure of the chloride melt.

Fabrication and Magneto-Optical Properties of Yb2O3 Based Ceramics

Transparent ceramics based on ytterbium oxide have been successfully produced by vacuum sintering of self-propagating high-temperature synthesized powders with use of a La2O3 sintering aid. Phase composition and microstructure of the initial powders were studied by X-ray diffraction analysis and scanning electron microscopy. It was found that addition of 5 mol.% of La2O3 does not cause formation of secondary phases in the Yb2O3 powders. The 4% La:Yb2O3 ceramics showed the best in-line transmittance of 73% at a wavelength of 2 μm among the studied samples. Dependence of the Verdet constant on wavelength was investigated in the range of 0.4–2 μm. The most promising finding is use of the obtained material as Faraday isolators in the wavelength region of ~1.5 μm, where there are no absorption bands, and the Verdet constant is 8.6 rad/(T*m).

Ytterbium disilicate-based glass-ceramic as joining material for ceramic matrix composites

A key aspect of ceramic matrix composites integration is related to a reliable joining technique. An ytterbium disilicate based glass-ceramic material is processed by reactive viscous flow sintering between a barium aluminium borosilicate glass and ytterbium oxide and it is used to join SiC/SiC and C/SiC composites. The joining temperature and the in situ formation of the Yb2Si2O7 is optimised at 1200°C without pressure, on the basis of the sintering and crystallisation mechanisms. The mechanical characterization of SiC/SiC and C/SiC joined with the ytterbium disilicate-based glass-ceramic, tested by single-lap offset at RT, exhibits an apparent shear strength of 35 MPa, similar to their interlaminar shear strength.The proposed system displays self-healing behaviour at 1000 °C and 1150 °C, as demonstrated by the partial and complete sealing of induced cracks by Vickers indentation on its surface at different loads, thus suggesting that it can effectively be used as promising joining material for CMCs.

Preparation of single-phase YbB6 by low-temperature solid-state reaction method using iodine

In this study, low-temperature solid-state synthesis of pure nanocrystalline ytterbium hexaboride (YbB6) employing iodine-based reduction method has been discussed. For the reduction reaction, the mechanically activated powder mixture of ytterbium oxide, boron oxide, magnesium, and iodine was heated up under Ar in a quartz tube to 85 °C. All reaction byproducts, viz. MgO, Mg3(BO3)2, and YbI2, were removed by hot acid leaching with 3 M HCl solution to form pure YbB6. The morphological and phase structure of the synthesized YbB6 powder were analyzed by X-ray diffractometry (XRD), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. The crystalline phases obtained were refined by multi-phase Rietveld refinement. XRD and Raman spectroscopy showed a contrast between the nano-YbB6 formed by the present low-temperature iodine-based reduction method versus mechanochemical method. The YbB6 produced by the low-temperature iodine reduction method is highly crystalline in nature, whereas YbB6 produced by mechanochemical method is less crystalline or conversely more amorphous in nature. The iodine-based reduction method indeed played a definitive role to allow the reaction to take place at a lower temperature enabling the formation of nanocrystalline YbB6.

Diffusion-activated high performance ZnSnO/Yb2O3 thin film transistors and application in low-voltage-operated logic circuits

The flourishing metal-oxide high-k dielectric materials have been regarded as the vital components of low voltage operated flexible transparent electronic devices. We herein report that ytterbium oxide (Yb2O3) and ZnSnO (ZTO) thin films were firstly integrated into ZTO-based thin film transistors (TFTs) with superior performance. Results have indicated that the 500 ℃-annealed ZTO/Yb2O3 TFTs possess the large saturation mobility of 9.1 cm2 V−1 S−1 and the high on/off current ratio of 2.15 × 107, which even surpass those of reported In-based TFTs. The deteriorative electrical properties in the aging process can be attributed to the carrier capture mechanism. However, the 460 ℃-processed TFTs demonstrate a tenfold increase in saturated mobility and an increase in on/off current ratio after 10 days aging. The inspiring electrical properties are attributed to the diffusion-activated carrier enhancement mechanism and electrons donor role of water molecular, which introduces a facile method to boost the device performance at lower processing temperatures. The neglected threshold voltage variations of 0.06 V and −0.2 V have been detected after bias stability experiments. The superior bias stability can be attributed to the charge delay effect induced by the continuous electric field. Meanwhile, the ultrahigh on/off current ratio of 1.1 × 107 and the recoverable transferring performance have verified the aging-activated mechanism. To confirm its potential application in digital circuits, a resistor-loaded inverter with gain of 5.6 has been constructed and good dynamic response behavior have been detected at a low voltage of 2 V. As a result, it can be concluded that the high temperature annealing TFTs need immediate encapsulation, while the performance of the lower temperature processing samples can be optimized after aging treatment, indicating the potential prospect in low power consumption large-scale flexible transparent devices.

Anatase–Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO2 Films Deposited by Acid Sol–Gel Dip-Coating Method

A method to prepare Yb-doped TiO2 is proposed, using titanium isopropoxide and ytterbium oxide. Thin films and powders are produced through the sol–gel technique where the Yb concentrations are 0.01 at.%, 0.02 at.%, 1 at.%, 2 at.% 4 at.% and 8 at.%. The increase in the doping concentration intensifies gradually the sample transparency for the whole observed spectrum and reaches the transparency degree of the undoped sample with the highest concentration of ytterbium. By means of x-ray diffraction (XRD) we find that the solution’s pH leads to the formation of a rutile structure which is compensated for by lanthanide doping, inhibiting the anatase–rutile phase transformation. Then, the XRD profile depends on the Yb concentration, being mostly anatase for undoped and highly (8 at.%) doped samples, with mixed ratios of these two phases in other concentrations. Maintaining an acid solution leads to fewer intergrain defects in the rutile structure contributing to higher conductivity. Photo-induced investigation of 8 at.% Yb-doped thin film, using several light sources leads to distinct behavior concerning the excitation of intra-bandgap states and/or electron–hole pairs. This result helps to understand the electronic transport in Yb-doped TiO2 and shows that devices based on its conductivity may have improved performance by irradiation with controlled light energy.

Das Ytterbium(III)-Oxidbromid-Oxidotellurat(IV) Yb3O2Br[TeO3]2

Abstract The ytterbium(III) oxide bromide oxidotellu-rate(IV) Yb3O2Br[TeO3]2 was obtained from a mixture of Yb2O3, YbBr3 and TeO2 in a molar ratio of 2:1:2 along with an excess of KBr as fluxing agent in evacuated fused silica ampoules after 10 days at T = 800 °C and subsequent slow cooling to room temperatures as colorless, plate-shaped single crystals. Its triclinic crystal structure (a = 663.97(5), b = 697.46(5), c = 1080.15(8) pm, α = 105.102(3), β = 90.931(3), γ = 100.034(3)°; Z = 2, space group: P 1 ‾ $‾{1}$ ) displays three crystallographically different Yb3+ cations with coordination numbers of six, seven and eight. Six out of eight distinct oxygen atoms belong to two independent ψ1-tetrahedral [TeO3]2−anions, whereas the other two represent O2− anions in tetrahedral coordination of four Yb3+ cations each, not having any contact to tellurium. Condensed via common vertices and edges, these [OYb4]10+ tetrahedra form cationic layers ∞ 2 ${}_{\infty }{}^{2}$ {[O2Yb3]5+}, which spread out parallel to the (001) plane. Two discrete [TeO3]2− groups and one Br− anion per formula unit take care of their three-dimensional interconnection along [001] and the overall charge balance of Yb3O2Br[TeO3]2. Remarkable interactions between the lone pair of electrons at the Te4+ cations of the ψ1-tetrahedral [TeO3]2− anions and those at the Br− anions are discussed.

Ab initio molecular dynamics simulations and Raman spectra of the YbCl3 - KCl and Yb2O3 - YbCl3 - KCl ionic melts

A direct reduction of solid ytterbium oxides into the metal in molten salts is a promising environmental friendly process. To understand the phenomena, which occur during the electrochemical ytterbium production, data on the structure of ytterbium-containing oxide-salt melts are required. In this study, using ab initio molecular dynamics and in situ Raman spectroscopy, we bring insight on the local structure of these systems by the examples of YbCl3–KCl chloride melt and Yb2O3–YbCl3–KCl oxide-chloride melt with a Yb2O3 concentration up to 2 mol%. We show that there are octahedral species [YbCl6], which, with an increase in YbCl3 concentration, can combine into a weakly bonded network through the bridging chlorine anions. Ytterbium oxide in the chloride melt dissociates to form [OYb3] ionic groups, which are incorporated into the melt structure.

Erbium spectral-luminescent characteristics in bromide-fluoride photo-thermo-refractive glasses

Subject of Research. The paper presents the study of spectral-luminescent characteristics of erbium ions in bromide- fluoride photo-thermo-refractive glasses with 0.1 mol% of erbium oxide and 1-2 mol% of ytterbium oxide concentration. Such spectroscopic parameters as stimulated emission cross-section of erbium ions at a wavelength of 1.5 microns, the efficiency of energy transfer from ytterbium to erbium ions, and the quantum efficiency are calculated based on the measured absorption spectra of glasses under study. The gain/loss spectra of erbium ions in the infra-red range are calculated for various population inversion values. Methods. Bromide-fluoride photo-thermo-refractive glasses were synthesized in an electric furnace at the temperature of 1480 °C for 5 hours in the air. Judd-Ofelt theory was used for determination of spectroscopic intensity parameters. The amplification spectra were obtained using McCumber theory. Main Results. It was found that the stimulated emission cross-section of erbium ions at a wavelength of 1.5 microns is typical for erbium in silicate glasses. The quantum efficiency of radiation at the same wavelength reached 95 %, and the energy transfer efficiency was 86 %. The gain factor had a positive value when the population inversion parameter was higher than 0.5. Practical Relevance. Bromide-fluoride photo-thermo-refractive glasses activated with erbium and ytterbium ions have spectral-luminescent characteristics comparable with commercial laser silicate glasses. In addition, they allow for recording of highly efficient Bragg gratings. Thus, these glasses can be promising candidates for creating distributed feedback lasers with ultra-narrow spectral lines.

Bioaccumulation of ytterbium oxide nanoparticles insinuate oxidative stress, inflammatory, and pathological lesions in ICR mice.

With the rapid development in nanoscience and nanotechnology, rare earth oxide nanomaterials (REO-NMs) have been increasingly used due to their unique physical and chemical characteristics. Despite the increasing applications of REO NPs, scarce information is available on their detrimental effects. In the current study, we investigate the toxic effect of ytterbium oxide nanoparticles (Yb2O3 NPs) in mouse model by using various techniques including inductively coupled plasma mass spectrometry (ICP-MS) analysis over 30days of exposure. Furthermore, we elucidated lung lavage fluid of mice for biochemical and cytological analysis, and lung tissues for histopathology to interpret the NP side effects. We observed a significant concentration of Yb2O3 NPs accumulated in the lung, liver, kidney, and heart tissues. Similarly, increased bioaccumulation of Yb content was found in the olfactory bulb compared to other reigns of brain. The cytological analysis of bronchoalveolar lavage fluid (BALF) revealed a significant elevation in the percentage of neutrophils and lymphocytes. Biochemical analysis showed an instilled Yb2O3 NPs, showing signs of oxidative damage through up-regulation of 60-87% of MDA while down-regulation of 20-40% of GSH-PX and GSH content. The toxicity pattern was more evident from histopathological observations. These interpretations provide enough evidence of bioaccumulation of Yb2O3 NPs in mice tissues. Overall, our findings reveal that acute exposure of Yb2O3 NPs through intranasal inhalation may cause toxicity via oxidative stress, which leads to a chronic inflammatory response. Graphical abstract Graphical illustrations of experimental findings.

Green synthesis of ionic liquid assisted ytterbium oxide nanoparticles by Couroupita guianensis abul leaves extract for biological applications

• The Yb 2 O 3 and IL-Yb 2 O 3 noparticles were prepared in hydrothermal method by Couroupita guianensis abul leaves extract. • The synthesized Yb 2 O 3 , IL-Yb 2 O 3 NPs have BCC structure and crystalline size of 40 and 35 nm. • The chemical states and elements confirmed by XPS and EDX spectroscopy. • The anti-inflammatory activities of IL-Yb 2 O 3 showed higher inhibition (%) than Yb 2 O 3 and diclofenac sodium. • The antioxidant assay of IL-assisted Yb 2 O 3 NPs has a higher effect than Yb 2 O 3 . Rare earth element ytterbium oxide (Yb 2 O 3 ) and ionic liquid (IL) added ytterbium oxide (Yb 2 O 3 -IL) nanoparticles (NPs) were synthesized using Couroupita guianensis abul leaves extract by hydrothermal method. The synthesized Yb 2 O 3 and Yb 2 O 3 -IL NPs are of BCC structure and crystalline size of 40 and 35 nm. Functional group and vibrational mode were analyzed by FTIR and Raman spectroscopy and the resultant Yb-O stretching peak at 618 and 588 cm −1 . The optical absorption at 239 and 230 nm for Yb 2 O 3 and Yb 2 O 3 -IL NPs were studied by UV–vis spectroscopy. The relative high-intensity emission peaks at 424 (blue) and 583 (yellow) were confirmed by photoluminescence spectroscopy. The particle size of Yb 2 O 3 -IL observed in the range of around 15–37 nm was confirmed by DLS method and the results matched with SEM analysis. The Yb, O 1s and C 1s states and the corresponding binding energy (BE) values were confirmed by X-ray photoelectron spectroscopy. The hexagonal, spherical and rectangular shapes were identified by SEM and TEM analyses. Biological activities such as antibacterial against E. coli and S. aureus, anti-cancer against MCF-7 breast cancer cells, anti-inflammatory against bovine serum albumin denaturation with standard diclofenac and anti-oxidant against free radical scavenging assay with Vitamin C were also studied for the synthesized Yb 2 O 3 and Yb 2 O 3 -IL NPs.

Up-conversion luminescence of hafnium, erbium, ytterbium and lithium co-doped yttrium oxide

UP-conversion luminescence of hafnium, erbium, ytterbium and lithium multiple doped yttrium oxide powders are presented. The measured luminescent spectra were obtained using two different lasers with wavelengths of 980 and 1534 nm; emission peaks were observed in the ranges of 530–580 nm (green emission), 630–680 nm (red emission), 960–1100 nm (infrared emission) and 1510 to 1560 (infrared emission) corresponding to the different intra electronic energy levels transitions of the Er3+ and Yb3+ ions. These emission peaks manifest the interactions between these ions that propitiate the phenomenon of up-conversion. The incorporation of lithium in the samples allowed an increase in the luminescent emission of up to 88% for the red emission and up to 12% for the emission in the IR range with respect to the samples that were not doped with lithium. The powders, object of this study, were synthesized by means of the solvent evaporation technique using nitrates and chlorides as precursors. The analysis of XRD showed a cubic crystalline structure of yttrium oxide with the spatial group: Ia-3 (206). The obtained SEM images showed a granular morphology only for samples doped with lithium with dimensions less than a micron. The chemical composition was obtained by measurements of EDS and FT-IR and finally the decay times of the different luminescent emissions are also reported.

Spectroscopic and laser properties of erbium and ytterbium co-doped photo-thermo-refractive glass

Spectral-luminescent characteristics of erbium ions in photo-thermo-refractive (PTR) glasses doped with different concentrations of ytterbium and erbium oxides were investigated in this work. X-ray diffraction pattern of studied glasses was carried out. Judd-Ofelt parameters of intensity Ωt were obtained and used for deriving emission cross-sections and radiative lifetimes. It was found that the peak emission cross-sections values at a wavelength of 1.53 μm obtained from F-L and McCumber methods are 0.59 × 10−20 cm2 and 0.60 × 10−20 cm2, respectively, which are very similar and compared with those of silicate glasses. A quite high value of quantum yield at the wavelength of 1.53 μm for the sample with 0.1 mol% Er2O3 co-doped with ytterbium oxide has been investigated. Energy transfer efficiency from ytterbium ions to erbium ones was found to be 80% and 86% for erbium- and 1 mol% and 2 mol% Yb2O3-co-doped PTR glass, respectively. Laser properties of 2Yb-01Er PTR glass were carried out. The gain spectrum starts to be positive when the population inversion parameter gets to 0.5. Laser action was demonstrated at room temperature. It was found that the round-trip losses of the Er/Yb-PTR element are 0.28%.

Assessing the potential application of bio-compatibly tuned nanosensor of Yb2O3 for selective detection of imazapyr in real samples

Imazapyr is one of the frequently employed herbicide for controlling the growth of broad range of terrestrial and perennial grasses grown along the crop fields. The excessive utilization of imazapyr has contaminated the water level at an alarming rate. So, there is an urgent need to develop a cheap, selective and sensitive sensor for the detection of imazapyr. Here, in this paper a novel bio-compatibly tuned fluorescent-nanosensor of APTES coated ytterbium oxide (Yb2O3) was fabricated under hydrothermal conditions. The surface modification with APTES has provided better control over the optical and luminescence properties of Yb2O3 nanoparticles and has been turned out as a contemporary approach for designing potential sensor for harmful toxins i.e. imazapyr. The higher biocompatibility and fluorescence properties have made Yb2O3 as one of the selective and sensitive material for the estimation of imazapyr. The quenching of fluorescence intensity for APTES coated Yb2O3 NPs was greatly magnified by increasing concentration of imazapyr and displayed a linear trend from 0−200 ppm with detection limit value of 0.2 ppm. The developed sensor has possessed excellent efficiency for sample collected from real field conditions and provided the wider scope in herbicide sensing.

ZrO2–Sc2O3 Solid Electrolytes Doped with Yb2O3 or Y2O3

The effects of the Y2O3 and Yb2O3 co-doping impurities on the transport characteristics and stabilization of the cubic phase in solid solutions based on ZrO2–Sc2O3 were compared. The crystals of the (ZrO2)0.99 –x(Sc2O3)x(Yb2O3)0.01 and (ZrO2)0.99 –x(Sc2O3)x(Y2O3)0.01 (x = 0.08–0.10) solid solutions were grown by directed crystallization of the melt in a cold container. The high-temperature cubic phase was stabilized at a total concentration of stabilizing oxides of 11 mol % for (ZrO2)0.99 –x(Sc2O3)x(Y2O3)0.01 crystals and at 10 mol % for (ZrO2)0.99 –x(Sc2O3)x(Yb2O3)0.01 crystals. At (9–10) mol % scandium oxide, the high-temperature conductivity of the crystals co-doped with ytterbium oxide was higher than in the case of the crystals co-doped with yttrium oxide. The (ZrO2)0.9(Sc2O3)0.09(Yb2O3)0.01 crystals have maximum conductivity over the whole temperature range.

Fabrication, physical, optical characteristics and gamma-ray competence of novel bismo-borate glasses doped with Yb2O3 rare earth

New transparent bismuth borate glasses doped with ytterbium oxide (Yb2O3 = 0.0–5.0 mol%) have been fabricated. The amorphous nature of the glasses was checked via XRD measurements. The optical energy band gaps, and index of refraction of all fabricated glasses were determined with help of the absorbance spectra which measured from 200 to 1100 nm wavelength. The results revealed that the optical energy band gap for the glasses was between 2.56 eV for glass sample with Yb2O3 = 0.5 mol% and 2.84 for sample with Yb2O3 = 1.0 mol%. The refractive index was high (around 2.5). Moreover, gamma photons shielding factors have been evaluated for the glasses via mass attenuation coefficient (μ/ρ) which calculated using XCOM software over an extended energy range 0.015–15 MeV. The obtained μ/ρ for the glass samples were compared to some commercial glasses, concrete, and heavy metal oxides. Based on the (μ/ρ), another effective radiation shielding factors such as half value layer (HVL), effective atomic number (Zeff), and mean free path (MFP) were calculated. The shielding results showed that the HVL begin to increase and arranged in the order Yb0.0 > Yb0.1 > Yb0.5 > Yb1.0 > Yb3.0 > Yb5.0. Thus, the fabricated glasses can be used in different optical applications and as promising radiation shielding materials, especially Yb5.0, owns high μ/ρ and Zeff, low HVL and MFP.

A screen-printed electrochemical sensing platform surface modified with nanostructured ytterbium oxide nanoplates facilitating the electroanalytical sensing of the analgesic drugs acetaminophen and tramadol.

An electrochemical sensing platform based upon screen-printing electrodes (SPEs) modified with nanostructured lanthanide metal oxides facilitate the detection of the widely misused drugs acetaminophen (ACP) and tramadol (TRA). Among the metal oxides examined, Yb2O3 nanoplates (NPs) were found to give rise to an optimal electrochemical response. The electroanalysis of ACP and TRA individually, and within mixtures, was performed using cyclic and differential pulse voltammetry. The ACP and TRA exhibited non-overlapping voltammetric signals at voltages of +0.30 and + 0.67V (vs. Ag/AgCl; pH9) using Yb2O3-SPEs. Pharmaceutical dosage forms and spiked human fluids were analyzed in wide linear concentration ranges of 0.25-654 and 0.50-115μmol.L-1 with limits of detection (LOD) of 55 and 87nmol.L-1 for ACP and TRA, respectively. The Yb2O3-SPEs offer a sensitive and chemically stable enzyme-free electrochemical platform for ACP and TRA assay. Graphical abstractSchematic presentation of one-shot electrochemical analysis of misused drugs, tramadol (TRA) and acetaminophen (ACP) by utilizing ytterbium oxide nanoplates modified screen-printed electrodes (Yb2O3-SPEs). The Yb2O3-SPEs showed interesting responses for ACP and TRA within pharmaceutical formulations and human fluids.

A simple separation system for elimination of molecular interferences for purity determination of europium and ytterbium oxides by HPLC-ICP-MS

A simple and rapid HPLC-ICP-MS method for determination of ultra-trace REE impurities in highly pure Eu2O3 and Yb2O3 has been developed.

Oxidation kinetics of supersonic atmospheric plasma spraying ytterbium oxide doped molybdenum silicide coating

Rare earth oxides usually play an active role in modifying the microstructure and oxidation resistance of silicide coatings, but its modification mechanism has not yet been clarified. In this work, molybdenum silicide (MoSi2) coating with different contents of ytterbium oxide (Yb2O3) was fabricated using supersonic atmospheric plasma spraying, and its microstructural evolution and oxidation behavior were investigated. Experimental results shown that the morphological characteristics of produced SiO2-rich glass scale varied with the doping of Yb2O3, which noticeably affected the oxidation resistance of sprayed MoSi2-Yb2O3 coatings. All coated specimens exhibited a parabolic oxidation behavior, wherein the MoSi2-10 wt%Yb2O3 coating possessed the smallest parabolic constant and the lowest specific mass loss with 100 h oxidation at 1500 °C due to the absence of SiC-depleted region and the formation of continuous multicomponent compound scale. Given this, Yb2O3 additive with proper concentration not only guaranteed the sufficient filling of open spaces in SiO2 network by Yb3+ cations, but also strengthened the Si–O bonds to increasing the viscosity of SiO2 glass, thereby delaying the effective delivery of reactive oxygen species inwardly.