Rare Earth Er Research Articles

Precipitation behavior, mechanical properties, and corrosion resistance of rare earth–modified Al-Zn-Mg-Cu alloys

In this study, we evaluated the microstructure, mechanical properties, and corrosion resistance of four types of 7055 alloys with and without the addition of rare earth elements (Er, Pr) elements. The results show a large number of coarse residual phase particles in the matrix of the 7055 alloy without the addition of rare earth elements, and the area proportion of residual phase is 3.56%; the proportion of low angle grain boundaries (LAGBs) after solid solution treatment is 31.1%. For the three other alloys that incorporate a rare earth element, the number of residual phases in the matrix is decreased, and the proportion of LAGBs is increased. As a result, the 7055 alloy with Pr (7055-Pr alloy) has the lowest number of residual phases, and the area proportion of residual phase is 1.41%; the 7055 alloy with Pr and Er (7055-Pr-Er alloy) has the highest proportion of LAGBs, which is 41.5%. Compared to the untreated 7055 alloy, the elongation and corrosion resistance of the three alloys with a rare earth element are increased. The increase in elongation is due to a reduction in the number of residual phases in the matrix, while the enhanced corrosion resistance is mainly due to the formation of Al3(Er, Zr) particles as a result of adding Er, which could pin the grain boundaries. Thus, the migration of LAGBs to high angle grain boundaries (HAGBs) is inhibited, the LAGBs are retained, and the corrosion resistance of the alloy is enhanced.

The effect of rare earth element doping on thermoelectric properties of GeTe

GeTe has attracted extensive attention due to high thermoelectric performance. Herein, we comprehensively investigate the effect of rare earth element (Eu, Gd, Er and Tm) substitutions at Ge site of GeTe on its thermoelectric performance. It is found that the substitution limit of Eu, Gd, Er and Tm at Ge site of GeTe increases from 0.8 to 1.8 mol.% with increasing atomic number. The local magnetic moment arising from the substituted rare earth element enhances the Seebeck coefficient and in turn results in enhanced power factor at the entire measurement temperature range (from 303 to 723 K). Additionally, the increasing substitution limit with increasing atomic number of rare earth element strengthens the mass and strain-field fluctuations, which contributes to strengthened phonon scattering, and leads to reduced lattice thermal conductivity. The simultaneously enhanced power factor and reduced lattice thermal conductivity enhances the dimensionless figure of merit at the entire measurement temperature range, and correspondingly enhances the average dimensionless figure of merit from 0.38 of GeTe to 0.63 of Ge0.98Er0.02Te. This work indicates rare earth element can be used an effective dopant in GeTe to improve the thermoelectric properties.

Rare-earth elements detection using diatomic molecular laser-induced plasma spectroscopy

The detection of Rare-Earth-Elements by LIBS by their atomic and ionic emission in many cases is difficult due to significant spectral interferences from other members of this group and accompanying elements. Another potential detection mode is to use molecular emission. It was previously considered that only La, Y, and Sc form analytically useful molecules in Laser-Induced Plasma. We proved that the molecules of other rare-earth elements (Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Y, and Lu) with oxygen appear effective for analytical purposes. The type of the emission spectrum depends on specific element molecular weight and differs for Light and Heavy REE sub-groups. This approach is demonstrated for Gd analysis in ceria (CeO2) and in permanent B-Fe-Nd and Sm-Co-Ni magnets. The presence of molecular emission of Rare-Earth-Elements opens an opportunity to apply Laser Ablation Molecular Isotopic Spectrometry and Molecular Laser-Induced Fluorescence - LIBS combination for their isotopes analysis.

Effects of Er3+ doping on structure and thermal properties of (Sm1–xErx)2Zr2O7 ceramics for thermal barrier coating

Rare earth Er3+ doped (Sm1–xErx)2Zr2O7 (x = 0.1, 0.2, and 0.3) ceramic samples were synthesized using a solid state reaction method. The microstructure and thermal properties of these ceramics were investigated to evaluate their potential as thermal barrier coating materials. The results show that ceramics are compact with regular-shaped grains of 1–5 μm size. (Sm1–xErx)2Zr2O7 has a pyrochlore structure mainly determined by ionic radius ratio, but the ordering degree decreases with increase of the Er2O3 content. There is no phase transformation from 1000 to 1200 °C, and the (Sm1–xErx)2Zr2O7 ceramics exhibit excellent phase stability during thermal treatment at 1200 °C for 100 h and 1400 °C for 50 h. The thermal conductivities of dense (Sm1–xErx)2Zr2O7 ceramics range from 1.52 to 1.59 W/(m·K), which is lower than that of Sm2Zr2O7, and decrease as the Er2O3 content increases. Besides, the thermal expansion coefficient of (Sm1–xErx)2Zr2O7 is higher than that of Sm2Zr2O7.

Er3+ and Sr(Bi0.5Nb0.5)O3-modified (K0.5Na0.5)NbO3: A new transparent fluorescent ferroelectric ceramic with high light transmittance and good luminescence performance

In this work, (K 0.5 Na 0.5 )NbO 3 –Sr(Bi 0.5 Nb 0.5 )O 3 : x wt% Er 3+ ( x = 0.1–0.4) transparent fluorescent ferroelectric ceramics were prepared using traditional solid-phase method. By solid solution of the second component Sr(Bi 0.5 Nb 0.5 )O 3 (SBN) and doped rare earth Er 3+ to modify (K 0.5 Na 0.5 )O 3 (KNN), it was successfully prepared with good luminescence performance while maintaining ceramic samples with excellent light transmittance. Results show that the representative 0.94(K 0.5 Na 0.5 )NbO 3 -0.06Sr(Bi 0.5 Nb 0.5 )O 3 : 0.1 wt%Er 3+ ceramic sample has a light transmittance of 80.25% in the near-infrared band (1100 nm). Meanwhile, in the visible light band (780 nm), the light transmittance is maintained at 71.95%. At the same time, the ceramic sample has good up-conversion luminescence performance, with two green light emissions and one red light emission at 525, 550 and 665 nm. The SEM photos show that the crystal grain size of the ceramic sample reaches the nanometer level with a fine and dense microstructure. The XRD pattern shows that the ceramic sample is in the pseudo cubic phase structure with the weakest optical anisotropy. In addition, the introduction of Bi 3+ makes the ceramic samples significantly suppress P r while maintaining a high P max , the ceramic samples have certain ferroelectric properties and good energy storage potential. This work has prepared an excellent multifunctional material, which provides helpful references for the development of opto-electronic materials.

Engineering the doping amount of rare earth element erbium in CdWO4: Influence on the electrochemical performance and the application to the electrochemical detection of bisphenol A

Rare earth elements Er doped CdWO4 (Er-CdWO4) nanorods were successfully prepared. The morphology, crystal structure, chemical environments and electrochemical properties of Er-CdWO4 nanomaterials were regulated by changing the doping amount of Er. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) have shown that the introduction of moderate content of Er could optimize the morphology of CdWO4. X-ray diffraction (XRD) results suggested that the larger Er ions partially replaced the Cd ions in CdWO4 nanocrystals and produced favorable lattice gaps and defects around the unit cell. The high-resolution X-ray photoelectron spectroscopy (XPS) of O 1 s and the enhanced peak intensity in electron spin resonance (EPR) declared that the doping of Er generated more oxygen vacancies in Er-CdWO4. Based on the physico-chemical characterizations, 0.5 wt% Er-CdWO4 was confirmed to be the best electrocatalyst within the tested samples, which exhibited the fastest electron transfer performance and the strongest electrocatalytic capacity to BPA. Taking the low-cost and simply prepared Er-CdWO4 with the optimal content of Er as the electrode modifier, a novel electrochemical sensor (Er-CdWO4/CPE) for BPA has been constructed for the first time, which exhibited the wide linear range from 0.01 to 6 μM and the limited detection of 0.003 μM, respectively. Moreover, satisfactory reproducibility, stability and anti-interference performance were also achieved on Er-CdWO4/CPE. Meanwhile, the proposed sensor successfully realized the determination of BPA spiked in local tap water samples.

Dynamic corrosion mechanical properties of magnesium alloys with Erbium in the chloride ions environment

The X-ray diffraction (XRD), scanning electron microscope (SEM), weight loss corrosion rate, corrosion residual strength (CRS), and slow strain rate tensile (SSRT) methods were used to study the effects of the addition of rare earth Erbium (Er) on the dynamic corrosion mechanical properties of the AM50 magnesium alloy. The results show that after Er was added, a new phase of Al3Er appeared and the microstructure was refined. The corrosion resistance of rare earth Er addition to the alloy was 0.5% > 1.5% > 1.0% > 0. Furthermore, the corrosion rates decreased in 432 h. The CRS results within 168 h show that the strength after an addition of 0.5% Er was the highest and the decline rate was the smallest. According to the shape of the tensile curve of CRS and the morphology of the tensile fracture, the addition of rare earth Er did not change the fracture form of the alloy, which remained as quasi-cleavage.

Residual service life of erbium-modified AM50 magnesium alloy under corrosion and stress environment

Abstract Magnesium alloy will decrease strength with corrosion in use, thus affecting their service life. Service life as a structural material under stress and corrosion is one focus of the magnesium alloy used as structural material, and how to improve the residual service life of magnesium alloy is an important scientific issue. The X-ray diffraction, scanning electron microscopy, and slow strain rate tensile (SSRT) tests are used to study the residual service life of erbium (Er) effect in the AM50 magnesium alloy in air, distilled water, and NaCl solution. The results show that after rare earth Er addition to the AM50, the white granular Al3Er intermetallic compound was formed. With Er content increasing, the quantity of Al3Er phase was increased and the volume of β-Mg17Al12 phase was decreased. The SSRT results show that residual service life ratio increased with the Er addition compare with no Er alloy in distilled water. However, in 3.5% NaCl solution, 0.5% Er alloy shows the best service life. Moreover, Er addition does not change the alloy fracture mode, which remains quasi-cleavage. The main cause of the decline in service life in magnesium alloys is the change in surface morphology owing to the pitting corrosion nucleation and growth, which affects the stress distribution of the sample. The mechanism of film cracking plays a major role in the fracture process with the Er increased to change the surface morphologies.

Synergistic effects of Ionquest 801 and Cyanex 572 on the solvent extraction of rare earth elements (Pr, Nd, Sm, Eu, Tb, and Er) from a chloride medium

A binary mixture of Ionquest 801 and Cyanex 572 was employed to study their synergistic effect on the solvent extraction and separation of rare earth elements (praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), terbium (Tb) and erbium (Er)) dissolved in a chloride solution. The results demonstrated a significant synergistic effect of 50% vol. Ionquest 801 and 50% vol. Cyanex 572 at pH of 1.5 in the extraction of heavy rare earth elements (HREEs). The maximum percentage extraction of the HREEs, Er3+ and Tb3+, under the optimized condition, were 95.7% and 71.7%, respectively; also, their distribution coefficient was improved, DEr (22.61) and DTb (2.54). Under that optimum condition, the extraction efficiencies of Nd (light rare earth element, LREE), Pr (LREE), Eu (middle rare earth element, MREE), and Sm (MREE) were 28%, 27%, 40%, and 38%, respectively. Additionally, the distribution coefficients of the HREEs to those of LREEs and MREEs were improved. For example, the measured separation factor for some of the couples were: Er/Pr: 61.31, Er/Nd: 57.77, Er/Sm: 36.44, Er/Eu: 33.19, Tb/Pr: 6.88, Tb/Nd: 6.48, Tb/Sm: 4.09 and Tb/Eu: 3.72. Both extractants individually showed similar performance in the extraction of HREEs. However, the highest efficiencies of the extraction of LREEs and MREEs were obtained solely with Cyanex 572. In contrast, Ionquest 801 showed little tendency towards extracting LREEs and MREEs, especially towards LREEs. Overall, the addition of Ionquest 801 to Cyanex 572 resulted in increased extraction of HREEs compared to the same in the sole Cyanex 572 and Ionquest 801. Additionally, the selectivity of the separation of HREEs from LREEs and MREEs was improved. The synergistic effect was concluded to result from changes in the phosphinic and phosphonic acids ratio in the extractant. By plotting McCabe-Thiele diagrams, it was confirmed that the complete extraction of Er3+ and Tb3+ occurred at the 3rd and 6th extraction stages, respectively. Stripping REE3+ from the loaded organic solution, using HCl with different concentrations, was investigated and the maximum stripping percentages reached were 92.2% for Er3+ and 55.8% for Tb3+ using a 4 M HCl solution.

Geochemistry of rocks (Late Cretaceous) in the Anambra Basin, SE Nigeria: insights into provenance, tectonic setting, and other palaeo-conditions

The geochemistry of Late Cretaceous sandstones and shales in the Anambra basin has been investigated by relatively few subsurface data-based studies, thus, there is a need for subsurface geochemical characterisation of the basin's fill provenance, tectonics, and palaeo-conditions (source rocks palaeo-weathering, palaeo-climate, and palaeo-redox). This paper presents the geochemistry of sandstones and shales from cored sections (n = 10) of the Amansiodo_1 well (located in the Anambra basin) with the intent of unravelling the provenance, tectonic setting, and palaeo-conditions. Major elements (n = 10) and the trace element concentrations of Sc, Be, V, Sr, Y, Zr, and Ba were obtained using fusion inductively coupled plasma. Trace (n = 24) and rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) concentrations were obtained using fusion mass spectrometry analytical method.Based on geochemical discrimination diagrams and element ratios such as Al2O3/TiO2, TiO2/Zr, Th/Sc, and La/Th; it is suggested that the studied samples from the Anambra Basin were derived from mixed sources (mafic, felsic, and intermediate) from the adjoining basement rocks, and recycled sediments from the Abakaliki uplift or high. The high-silica and low-silica tectonic multidimensional discrimination diagrams showed that the examined rocks might have originated from rift (69 % probability), collision (24 % probability), and continental arc (7 % probability) settings. The plagioclase index of alteration (PIA), chemical index of weathering (CIW), and chemical index of alteration (CIA) values (average > 80) of studied rock specimens indicate an intensive degree of chemical weathering of the source rocks. The plot of Al2O3 + K2O + Na2O versus SiO2, weathering indices (PIA, CIW, and CIA), and Sr/Cu and Rb/Sr ratios; as well as U, Mo, Th/U, V/Cr, V/Sc, U/Th, and Ce/Ce∗ all suggested warm to hot, humid and/or arid palaeo-climate in an oxic palaeo-redox condition during the accumulation of the examined samples.

MICROSTRUCTURE AND MARTENSITIC TRANSFORMATION OF Ni_{50}Ti_{50-x}Er_{x} SHAPE MEMORY ALLOYS

The effect of rare earth element Er addition on the microstructure and phase transformation behavior of Ni_{50}Ti_{50-x}Er_{x} (x =0, 1, 5) shape memory alloy was investigated experimentally. The results showed that the microstructure of Ni-Ti-Er ternary alloys consists of the NiEr precipitate and the NiTi matrix. A one-step martensitic transformation was observed in all alloys. The martensitic transformation temperature M_s increased gradually with increasing Er content.

Remodelling a shp: Transmetalation in a Rare-Earth Cluster-Based Metal-Organic Framework.

Postsynthetic modification of metal-organic frameworks (MOFs) is an important strategy for accessing MOF analogues that cannot be easily synthesized de novo. In this work, the rare-earth (RE) cluster-based MOF Y-CU-10 with shp topology was modified through transmetalation using a series of RE ions, including La(III), Nd(III), Eu(III), Tb(III), Er(III), Tm(III), and Yb(III). In all cases, metal exchange higher than 70% was observed, with reproducible results. All transmetalated materials were fully characterized and compared to the parent MOF Y-CU-10 with regard to crystallinity, surface area, and morphology. Additionally, single-crystal X-ray diffraction measurements were performed to provide further evidence of transmetalation occurring in the nonanuclear cluster nodes of the MOF.

Study on Phases Formation and Modification Ability of Rare Earth Elements La, Ce, Sm and Er in Al–Zn–Mg–Cu–Zr Alloy

Study on Phases Formation and Modification Ability of Rare Earth Elements La, Ce, Sm and Er in Al–Zn–Mg–Cu–Zr Alloy

Role of rare earth on the spectral properties of chalcogenide glassy alloys: A review

In this paper, recent results regarding rare earth element doped with chalcogenide glasses for optical gain media such as amplifiers and lasers are reviewed. Rare earth Chalcogenide glasses are formed when chalcogen elements (S, Se, Te etc.) are mixed with new additive elements (Ge, Ga, Sb, As etc.) and also with rare earth elements (Er, Dy, Pd, Pr etc.) from periodic table and prepared by melt quench technique (MQT). Rare earth element doped with chalcogenide glasses has been emerged as a suitable candidate for applications in the numeral passive and active. Among various materials, chalcogenide glasses show significant improvement in their emission properties in the optical communication range and spectroscopic properties. Finally, rare earth doped chalcogenide and optical fibers show potential for high power mid-infrared gain medium and their spectroscopic properties as well.

Preparation of Ti/SnO2-Sb/Rare Earth Electrodes Containing Different Contents of Ni Intermediate Layer for Efficient Electrochemical Decolorization of Rhodamine B

Water contamination by dyes discharged from many industries is an environmental issue of great matter. Electrochemical oxidation is an advanced approach for wastewater treatment. In this study, the composite electrodes of Ti/SnO2-Sb-Ni/rare earth have been modified using rare earth elements (Re) Gd, Ce, Eu, and Er and various molar ratios of tin and nickel intermediate layer, and their electrochemical oxidation effects were scrutinized. To analyze the decolorization performance of the electrodes, Rhodamine B (RhB) dye was utilized as a target pollutant. Accelerated life testing indicated that the longer service life could be observed in Ni (3.5%)/Re and Ni (5%)/ Re electrodes compared with other modified Ni (0%, 1%, and 2%)/Re electrodes. Compared with the color removal efficiencies of the Ni (2%)/Re electrodes, the decolorization rate of 90% after treatment for 60 min and the low energy consumption of 3.621 kW h·m−3 can be achieved at the Ni (2%)/Gd electrode under the experimental condition of 100 mg·L−1 RhB. The best decolorization rate was observed at the Ni (2%)/Re electrodes among other Ni and no adding Ni-doped Re electrodes. The characterization of the electrodes was described, consisting of surface morphology, oxygen evolution potential, and a crystallographic and elemental combination of the coatings.

Effects of rare earth elements doping on gas sensing properties of ZnO nanowires

The effects of rare earth elements (Ce, Eu, and Er) doping on the microstructure and gas sensing properties of ZnO nanowires were investigated. The Ce, Eu, Er-doped ZnO nanowires and pristine ZnO nanowires were synthesized via a solvothermal route. The structure of the prepared samples was studied and compared by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron microscopy. The gas sensors were fabricated by coating the prepared samples on aluminum oxides tube-based Au sensing electrode, with Ni-Cr heating wire to control the operating temperature. The operating temperature of all sensors was determined to be 300 °C with consideration of ethanol response. At this temperature, all sensors showed good ethanol sensing performance, with the 1%Ce-doped ZnO nanowires-based sensor exhibited the highest ethanol response over the other sensors. The mechanism for the microstructure and gas sensing behavior difference of various samples was discussed.

Rare-earth-regulated Ru-O interaction within the pyrochlore ruthenate for electrocatalytic oxygen evolution in acidic media

Ruthenium-based catalyst is one of the most active catalysts for oxygen evolution reaction (OER) in acid media. However, the strong bonding between the Ru sites and oxygen intermediates leads to high overpotential to trigger the OER process. Hence, pyrochlore rare-earth ruthenate (RE2-Ru2O7) structures with a series of rare-earth elements (Nd, Sm, Gd, Er, and Yb) were constructed to tune the electronic structure of the Ru sites. Surface structure analysis indicated that the increase of the radius of the rare-earth cations resulted in higher content of defective oxygen (the percentage of the defective oxygen increased from 29.5% to 49.7%) in the RE2Ru2O7 structure due to the weakened hybridization of the Ru-O bond. This reduced the valence states of the Ru sites and enlarged the gap between the 4d band center and the Fermi level (EF) of Ru, resulting in the weakened adsorption of oxygen intermediates and the improved OER performance in acid media. Among the as-prepared ruthenium pyrochlores, Nd2Ru2O7 displayed the lowest OER onset overpotential (210 mV) and Tafel slope (58.48 mV dec−1), as well as 30 times higher intrinsic activity and much higher durability than the state-of-art RuO2 catalyst.

Separation and solvent extraction of rare earth elements (Pr, Nd, Sm, Eu, Tb, and Er) using TBP and Cyanex 572 from a chloride medium

In this study, synergistic effect of Cyanex 572 mixed with TBP on the extraction and separation of six selected light, medium and heavy rare earth elements (REE), namely neodymium (Nd), praseodymium (Pr), samarium (Sm), europium (Eu), terbium (Tb), and erbium (Er), from the chloride medium was investigated. The results demonstrated that sole TBP is not a suitable extractant for the separation of the REEs from the chloride media. However, Cyanex 572 was identified as a suitable extractant for the separation of heavy REEs, Er, and Tb. At initial pH (pHi) of 1.5, the mixture of 25% TBP + 75% Cyanex 572 extracted about 70% and 85% of Er and Tb, respectively. The separation factor (SF) results of some couples were noteworthy: SFEr/Pr = 30.08, SFEr/Nd = 29.95, SFTb/Pr = 12.22, SFTb/Nd = 12.16, SFEr/Sm = 9.96. Furthermore, the extraction mechanism of these two heavy REEs was studied using slope analysis and Fourier transform infrared measurements (FT-IR). The results showed that Er and Tb were extracted as ErCl2R(HR)3TBP and TbCl2R(HR)3TBP complexes (presumably R and HR refers to Cyanex 572), respectively. The FT-IR spectra confirmed these obtained results qualitatively.

Electrochemical Recovery and Behaviors of Rare Earth (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb) Ions on Ni Sheets.

The electrochemical behaviors of rare earth (RE) ions have extensively been studied because of their high potential applications to the reprocessing of used nuclear fuels and RE-containing materials. In the present study, we fully investigated the electrochemical behaviors of RE(III) (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb) ions over a Ni sheet electrode in 0.1 M NaClO4 electrolyte solution by cyclic voltammetry between +0.5 and −1.5 V (vs. Ag/AgCl). Amperometry electrodeposition experiments were performed between −1.2 and −0.9 V to recover RE elements over the Ni sheet. The successfully RE-recovered Ni sheets were fully characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The newly reported recovery data for RE(III) ions over a metal electrode provide valuable information on the development of the treatment methods of RE elements.

Reversible and color controllable emissions in Er3+/Pr3+-codoped K0.5Na0.5NbO3 ceramics with splendid photochromic properties for anti-counterfeiting applications

It is highly significant to develop multi-mode optical anti-counterfeiting materials to efficiently fight against counterfeit products. In this study, we chose ferroelectric K0.5Na0.5NbO3 (KNN) with excellent photochromism properties as the host and rare-earth Er3+ and Pr3+ ions as dopants to prepare the Er3+/Pr3+-codoped KNN ceramics. The color-tunable emissions can be obtained from red-orange-yellow to green by controlling the excitation wavelength. Upon 980 nm excitation, the synthesized ceramics does not only have superior upconversion (UC) emission behaviors but also have good luminescence modulation properties based on the photochromism properties. It is found that the KNN:0.003Er3+/0.003Pr3+ sample with the optimal UC emission features shows a highest ΔRt value of 74.52% when irradiated by 390 nm light for 5 min, whereas the KNN:0.005Er3+/0.003Pr3+ ceramics also exhibit a high ΔRt value of 66.81% under 395 nm light irradiation. According to the XPS and EPR results, one knows that the mechanism of luminescence modulation is closely related to defects and traps caused by the oxygen vacancies. Furthermore, the optical information writing and erasing test is conducted, exhibiting a good reproducibility and fatigue resistance. These results reveal that the designed ceramics are appropriate for the anti-counterfeiting applications.