Neodymium Ions Research Articles

Design of coherent wideband radiation process in a Nd3+-doped high entropy glass system

We discover that the spatially coherent radiation within a certain frequency range can be obtained without a common nonlinear optical process. Conventionally, the emission spectra were obtained by de-exciting excited centers from real excited energy levels to the ground state. Our findings are achieved by deploying a high-entropy glass system (HEGS) doped with neodymium ions. The HEGS exhibits a much broader infrared absorption than common glass systems, which can be attributed to be high-frequency optical branch phonons or allowable multi-phonon processes caused by phonon broadening in the system. A broadened phonon-assisted wideband radiation (BPAWR) is induced if the pump laser is absorbed by the system. The subsequent low-threshold self-absorption coherence modulation (SACM) can be controlled by changing excitation wavelengths, sample size, and doping concentrations. The SACM can be red-shifted through the emission of phonons of the excited species and be blue-shifted by absorbing phonons before they are de-excited. There is a time delay up to 1.66 ns between the pump pulse and the BPAWR when measured after traveling through a 35 mm long sample, which is much longer than the Raman process. The BPAWR-SACM can amplify the centered non-absorption band with a gain up to 26.02 dB. These results reveal that the shift of the novel radiation is determined by the frequency of the non-absorption band near the absorption region, and therefore the emission shifts can be modulated by changing the absorption spectrum. When used in fiber lasers, the BPAWR-SACM process may help to achieve tunability.

Highly functional bio-based micro- and nano-structured materials for neodymium recovery

One of the main pillars of sustainable development is the preparation of functional materials derived from renewable resources. Nevertheless, facile methods to convert lignocellulosic biomass into value-added, highly functional materials remain limited. Here, we evaluate the potential of an acid-free method to convert a variety of lignocellulosic biomass into highly charged micro- and nano-structured materials. We show how the sequential oxidation of delignified (e.g., softwood pulp and cotton) or untreated (e.g., corncob and tomato peel) lignocellulosic sources yield three distinct products, including biopolymeric nanoparticles (BNP), solubilized biopolymers (SB), and microproducts (MP), bearing up to 6 mmol of carboxylate groups per gram, which is up to ∼ 500 % beyond the theoretical charge content of conventional cellulose nanocrystals (CNC). The main difference among the products was the type of nanoparticles: delignified sources yielded hairy cellulose nanocrystals, whereas lignin nanoparticles were formed from the untreated sources. As a proof-of-concept for the applications of these materials, we show that carboxylated cotton microproducts remove ∼ 92.5 mg of neodymium ions per gram from a dilute solution in less than 5 min and recover approximately 64 % of it via pH adjustment. This work may provide new opportunities for the conversion of a wide array of lignocellulosic biomass to highly functional biocolloids with extremely high charge density for advanced sustainable applications.

Energy levels, lifetimes and transition data for Cu-like Nd[formula omitted] to Br-like Nd[formula omitted] ions

We have performed calculations for Cu-like to Br-like neodymium (Nd) ions using the multiconfiguration Dirac–Hartree–Fock (MCDHF) and relativistic configuration interaction (RCI) approaches. An extensive set of fine structure energy levels, lifetimes, wavelengths, and radiative transitions for electric and magnetic multipole transitions is provided. We systematically include the electronic correlation effects between valence electrons and two subshells of core electrons. In the RCI procedure, both the Breit interaction and the leading quantum electrodynamic effects are taken into account. The reliability and accuracy are confirmed by comparing our results to accessible experimental and theoretical data.

Crowding of neodymium ions as a structural feature of fluorophosphate glasses

The rare-earth element of neodymium is used as a doping agent for a variety of alloys, as the base element for super magnets and in cryogenic industry. Inorganic glass industry represents a separate application for neodymium oxide. Having a high quantum yield of luminescence, such glasses are essential for the production of high-power optical quantum generators. Fluorophosphate glasses have a complex composition, specific physicochemical properties and spectral characteristics, and demonstrate specific matrix forming patterns when modifiers or glass forming agents are introduced. The current structural description of fluorophosphate glasses is lacking, which gives relevance to further studies into the structure of Ba(PO3)2 based pseudobinary glass system and barium fluoroaluminate. Microadditions of neodymium oxide were introduced as an activator during glass synthesis. Such glasses can be used as laser material. The authors examined the absorption and luminescence spectra of glass specimens containing neodymium. It is shown that fluorophosphate glasses are structurally heterogeneous systems that contain two typical activator coordination environments; introduction of fluorides in Ba(PO3)2 glass leads to neodymium ion segregation in the phosphate glass matrix. Specimens of crystallization resistant optical glass have been obtained. The paper describes optimum compositions of neodymium activated fluorophosphate glasses that retain the advantages of phosphate glass systems while shorter neodymium luminescence lifetimes have no noticeable impact on the glass performance.

The selective separation of neodymium from aluminum using ion flotation

In this study, fluorine ion was applied as a chelating agent to separate selectively neodymium ion from aluminum ion by ion flotation. The interactions of neodymium and aluminum ions with fluorine ions at different fluorine concentrations and pHs were investigated to determine species ions formed in solution. The results showed that the presence of fluorine ions increased the selective separation of neodymium ion, enhancing the selectivity coefficient during the process. A decrease in the selectivity coefficient was obtained with increasing the concentration of fluorine ion. As the fluorine ion concentration increased from 3.5 to 10 mM, there was an increase in the selectivity coefficient from 2.91 to 30.2 and then decreased using more fluorine. Selective ion flotation results indicated that neodymium ion recovery was higher than that of aluminum ions, indicating the ion recovery order based on the enhancing order of crystal ionic radius. Also, the scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDAX) and Fourier-transform infrared spectroscopy (FTIR) analyses results confirmed higher interaction of fluorine ions with neodymium ions compared to that of the aluminum ions in the solution.

Separation of lanthanum and neodymium in a hollow fiber supported liquid membrane: CFD modelling and experimental validation

Nickel metal hydride batteries find extensive use in many electronic devices. They contain a small amount of rare earth elements, such as, lanthanum and neodymium, which can be recovered from waste batteries, and reused. Hollow fiber supported liquid membranes (HFSLM) have been used for separation of different metal ions. In this work, a CFD model has been developed for a HFSLM to study the separation of lanthanum ion (La+3) and neodymium ion (Nd+3) from an aqueous solution. The model considers the effect of pH on distribution coefficient DM, which is a function of hydrogen ion (H+) concentration, and has a significant effect on extraction efficiency. The model was validated with the experimental data. An empirical model was fitted with the simulation data, and the parameters were optimized for the effective separation of La+3 and Nd+3. The maximum extraction of Nd+3 was predicted to be 44.97%, whereas extraction of La+3 was estimated to be 3.39%, at the optimized conditions of flow rate: 118.96 ml/min, feed pH: 3.41, and [PC88A]: 41.63 mol/m3, in once-through mode. The proposed CFD model could be helpful in design as well as, scale-up of HFSLM for separation of metal ions, by changing the design and process parameters.

The Effect of Neodymium(III) Ions on the Photoluminescence of Cadmium and Zinc Sulfides in a Polyacrylate Matrix

The Effect of Neodymium(III) Ions on the Photoluminescence of Cadmium and Zinc Sulfides in a Polyacrylate Matrix

Anomalous Sorption of Neodymium and Praseodymium Ions by Intergel System Polyacrylic Acid Hydrogel – Poly-4-Vinylpyridine Hydrogel

This paper is devoted to study of sorption properties (sorption degree, polymer chain binding degree) of intergel system hydrogel of polyacrylic acid (hPAA) – hydrogel of poly-4-vinylpyridine (hP4VP) in relation to neodymium and praseodymium ions. It was found that remote interaction of the polymers in intergel pairs provides significant changes of the electrochemical and volume gravimetric properties. Strong increase of the swelling degree of hPAA is observed at the ratio 17%hPAA-83%hP4VP; significant increase of swelling degree of hP4VP is observed at the ratio 83%hPAA-17%hP4VP. Individual hydrogels of PAA and P4VP do not have sufficiently high sorption properties – sorption degree of neodymium and praseodymium ions is not higher than 65 %, polymer chain binding degree is not higher than 55 %. High ionization of hPAA and hP4VP due to remote interaction effect provides significant increase (up to 30 %) of the sorption properties. Maximum sorption of neodymium and praseodymium ions occurs at the ratios 83%hPAA-17%hP4VP and 50%hPAA-50%hP4VP (sorption degree is 93.5 % and 93.6 %, respectively). The highest values of polymer chain binding degree (in relation to neodymium and praseodymium ions) are observed at the ratios 83%hPAA-17%hP4VP and 50%hPAA-50%hP4VP – binding degree is 73.2 % and 75.4 %, respectively. Remote interaction provides possibilities for creation of innovative sorption technologies for selective sorption of aimed rare-earth elements.

Development of neodymium (III) ions doped sodium fluoro-borate glass composite materials and study of the laser emission

Neodymium (III) ions doped sodium fluoro-borate (BCNF) glass materials have been prepared by the melt quenching method and Fourier transform infrared (FTIR) method was intended for the identification of the functional groups present in the BCNF host glass. X-ray diffraction (XRD) analysis is used for the study of structural details of the prepared glass composite materials. In order to study the spectroscopic properties of fabricated glasses, absorption, emission and decay measurements has been performed. Additionally, the spectroscopic properties of Nd3+ ions were analyzed using Judd-Ofelt theory. UV–Vis and Near-IR absorption spectra of glass composite samples reveal eleven significant peaks. Under the excitation of 808 nm laser diode, three near-IR emission bands are at around 876 nm, 1058 nm and 1331 nm from 4F3/2 → 4I9/2, 4I11/2 and 4I13/2 radiative transitions, respectively, were observed in the Nd3+ ions doped glass composite material. The lifetimes of this transition has been experimentally determined through decay profile studies. For all Nd3+ ion concentrations, the decay time curves of the 4F3/2 level were essentially single exponential.

Luminescence response of neodymium ions to phase transformations in yttria-based solid-solution nanopowders

Subject of study. In this paper, we describe the luminescence properties of nanopowders of composition (Nd0.008Y0.992)2O3, (Nd0.008Y0.992)2O3+6mol%ZrO2, and (Nd0.008Gd0.496Y0.496)2O3+5mol.%ZrO2 with various percentages of monoclinic and cubic phases. Method. Photoluminescence and pulsed cathodoluminescence spectra are recorded, followed by interpretation of the results obtained. Main results. In the process of studying the luminescence bands corresponding to the 4F3/2→4I9/2 and 4F3/2→4I11/2 energy transitions for neodymium ions in nanopowder crystalline lattices, we identify several spectroscopic and kinetic properties that can be used to identify the substances and determine the crystal phases present. We show that there is slight broadening of the spectral lines in the continuum base of the 4F3/2→4I11/2 manifold; the intensity level below which the bands merge into a continuum increases as the amount of structural disorder caused by the zirconium- and gadolinium-ion dopants in the Y2O3 increases. Practical significance. The distinctive features of the photoluminescence spectra and the kinetics of neodymium-ion luminescence in the 4F3/2→4I9/2 and 4F3/2→4I11/2 bands can be used for unique identification of the substances present and determination of the crystal phases thereof; this will be of practical interest in the development of high-bandwidth ceramic active elements.

Down- and up-conversion processes in Nd3+/Yb3+ co-doped sodium calcium silicate glasses with concomitant Yb2+ assessment

Novel Nd3+/Yb3+ co-doped sodium calcium silicate glasses were prepared by melting quenching method. Spectroscopic study was carried out as a function of doping content by fixing sensitizer (Nd3+) concentration to 0.2 mol% and adjusting activator (Yb3+) from 0 to 1.0 mol%. The energy transfer (ET) mechanisms between Nd3+ and Yb3+ are discussed based on their energy levels and excitation power-dependence emission intensity. Results show that the presence of Yb2+ might be considered for the Nd3+-free and co-doped samples. The ET was confirmed by the down-conversion NIR emission spectra of the doped and co-doped samples under excitation at 808 nm. The mechanisms observed seem to involve only one VIS absorbed photon for each NIR emitted via direct energy transfer between 4F3/2 of Nd2+ and 2F5/2 of Yb3+ compensated by phonon assistance due to energy gap between these levels. The efficiency of ET increases with the ytterbium content up to almost 90% for the sample with 1 mol% of Yb2O3, which was evaluated by lifetime measurements. Up-conversion photoluminescence by exciting trivalent ions of neodymium (808 nm) and ytterbium (975 nm) is reported. The observed up-converted emission bands are related to the 4f-4f transitions of Nd3+ and the spin-forbidden 5d-4f transition of Yb2+. Nd3+ up-conversion emission is observed under 975 nm excitation, presenting an almost quadratic emission dependence with power excitation, which suggests that two laser photons participate in the up-conversion (UC) process, showing that ET occurs by a phonon-assisted energy transfer and cooperative energy transfer.

Arsenate removal on the iron oxide ion exchanger modified with Neodymium(III) ions

In this study the iron oxide ion exchanger with the quaternary ammonium groups, Ferrix A33E was modified with neodymium (III) ions in order to obtain the new material Ferrix A33E-Nd(III) characterized by greater sorption efficiency of arsenate(V) ions. A33E-Nd(III) was described by various techniques including scanning electron microscopy SEM, nitrogen adsorption/desorption isotherms, Fourier transform infrared spectroscopy FTIR and X-ray photoelectron spectroscopy XPS. The point of zero charge, pHPZC was also determined. The kinetic and thermodynamic parameters of the arsenate(V) sorption were calculated. The experimental data was fitted to the four isotherm models - Langmuir, Freundlich, Dubinin-Radushkevich and Halsey. Kinetic and equilibrium studies allowed to get to know the behaviour of arsenate(V) ions during the sorption on A33E-Nd(III). The obtained material A33E-Nd(III)- was found to possess a larger maximum sorption capacity than A33E, great stability and the possibility of regeneration at least 3 times without a significant decrease in efficiency. This allows for the complete removal of As(V) ions from a solution with a concentration of 50 mg/dm3 in just 30 min. The Nd(III)-modification improved the sorption properties of the tested ion exchanger.

Application of the Remote Interaction Effect and Molecular Imprinting in Sorption of Target Ions of Rare Earth Metals.

The goal of the present work is a comparative study of the effectiveness of the application of intergel systems and molecularly imprinted polymers for the selective sorption and separation of neodymium and scandium ions. The following physico-chemical methods of analysis were used in this study: colorimetry and atomic-emission spectroscopy. The functional polymers of polyacrylic acid (hPAA) and poly-4-vinylpyridine (hP4VP) in the intergel system undergo significant changes in the initial sorption properties. The remote interaction of the polymers in the intergel system hPAA–hP4VP provides mutual activation of these macromolecules, with subsequent transfer into a highly ionized state. The maximum sorption of neodymium and scandium ions is observed at molar ratios of 83%hPAA:17%hP4VP and 50%hPAA:50%hP4VP. Molecularly imprinted polymers MIP(Nd) and MIP(Sc) show good results in the sorption of Nd and Sc ions. Based on both these types of these macromolecular structures, principally new sorption methods have been developed. The method based on the application of the intergel system is cheaper and easier in application, but there is some accompanying sorption (about 10%) of another metal from the model solution during selective sorption and separation. Another method, based on the application of molecularly imprinted polymers, is more expensive and the sorption properties are higher, with the simultaneous sorption of the accompanying metal from the model solution.

Column dynamic studies for lanthanum(III) and neodymium(III) sorption from concentrated phosphoric acid by strongly acidic cation exchange resin (SQS-6)

ABSTRACT In this work, solid-liquid extraction of lanthanum and neodymium ions by column technique from concentrated phosphoric acid solutions using the strongly acidic cation exchange resin was experimentally investigated. Measurements of breakthrough curves were measured as a function of column bed depth, initial metal concentration in the feed solution and flow rate. It was found that the breakthrough and time increased with the increase in bed depth and the total mass adsorbed by La(III) and Nd(III) increased with increasing bed depth. At higher initial metal concentrations, the column is quickly saturated, resulting in shorter breakthrough and exhaustion time. It was observed that with increasing the initial metal concentration from 0.10 to 0.50 g/L, the equilibrium adsorption capacities increase from 9.68 to 27.45 mg/g for La(III) and from 4.57 to 19.43 mg/g for Nd(III). Breakthrough time reaching saturation was increased significantly with a decrease in the flow rate. As the flow rate increased from 1.0 to 4.0 ml/min, the exhaustion time of La(III) and Nd(III) decreased from 135.0 to 40.0 min and from 90.0 to 35.0 min, respectively. The capacity of La(III) and Nd(III) was found to be 33.55 and 17.30 mg/g, respectively. The experimental sorption capacity and the time required for 50% adsorbate breakthrough (τ) are close to those calculated resulting from the Thomas and Yoon-Nelson model. These results indicate that the experimental data obey the Thomas and Yoon-Nelson model.

Features of the pulsed cathodoluminescence kinetics of neodymium ion in yttrium-aluminum garnet and yttria

The kinetics of pulsed cathodoluminescence of Nd3+ ions in single crystals, ceramics, and nanopowders of Nd3+ : Y3Al5O12 (Nd3+ : YAG) and Nd3+ : Y2O3 under excitation by a 2 ns electron beam with average electron energies of 130, 150, and 170 keV was studied. In this case, the luminescence of these substances occurs after the termination of the electron beam. In Nd3+ : YAG, there are optical transitions from the 2F25/2 level of the neodymium ion in the ultraviolet and visible regions of the spectrum, as well as from the 4F3/2 level in the near infrared region. In Nd3+ : Y2O3, there are not transitions from the 2F25/2 level of the neodymium ion, but infrared luminescence occurs from the 4F5/2 and 4F3/2 levels. The luminescence kinetics is characterized by rise and decay and it is described by the difference of two exponential functions. It is found that the characteristic luminescence decay times are the lifetimes of the 2F25/2, 4F5/2 and 4F3/2 emissive levels, and the rise time is determined by their pumping in recombination and relaxation processes. The rise mechanisms of pulsed cathodoluminescence are substantially different from the mechanisms of "phosphor ignition", which occur during ionization and excitation of the phosphor by an external source. Keywords: pulsed cathodoluminescence, neodymium ion, yttrium-aluminum garnet, yttria, kinetics, rise time, decay time.

Doping Effect of Neodymium Ions as Simulated An3+ on the Structure and Performance of the Granite Solidified Substrate

Doping Effect of Neodymium Ions as Simulated An3+ on the Structure and Performance of the Granite Solidified Substrate

Magnetic Properties of a Polyfluorene Derivative Metallopolymer Containing Neodymium Ions

AbstractThe magnetic properties of a polyfluorene derivative, {Poly[9,9’‐dihexylfluorene‐2,7‐yl)‐3,8‐(1,10‐phenanthroline)]} and its complexes with neodymium ions are explored and discussed in the light of the macromolecular configuration and photophysical properties. The pristine noncomplexed material is a diamagnetic material, and the introduction of Nd atoms in the polymer leads to a paramagnetic behavior over the entire temperature range. The prominent role of the morphology is demonstrated by comparison of two forms, with different ligands to the metal: one with bulky β‐diketone groups and another with small chorine as ligands. The large groups hinder interchain interaction, whereas the smaller salt forms favored interchain π‐stacking, providing a better interaction of the magnetic field with the polymer backbone, resulting in enhanced magnetic properties. The form with the β‐diketone groups exhibits a paramagnetic behavior whereas the one in the salt form presents ferromagnetic behavior at room temperature. This contribution brings solid confirmation to the importance of interchain interaction in the magnetic properties of conjugated polymers, opening a new way to the obtainment of magnetic conjugated polymers.

IMPACT OF NEODYMIUM AND SCANDIUM IONIC RADII ON SORPTION DYNAMICS OF AMBERLITE IR120 AND AB-17-8 REMOTE INTERACTION

The aim of this research work is comparative study of influence of ionic radii of heavy metal ions of neodymium and scandium on their sorption process from corresponding water solutions of sulfates by sorbents such as individual ion-exchangers Amberlite IR120, AB-17-8 and mixture of these sorbents related to interpolymer system Amberlite IR120-AB-17-8 at the various molar relations. Laboratory experiments of this work of sorption heavy ions of neodymium and scandium were carried out and inves-tigated by using the following physico-chemical methods of analysis: conductometry-based on the electrical conductor, pH-metry-based on the concentration of hydrogen ions, colorimetry, atomic-emission spectro-scopy. Ion-exchangers in the interpolymer system undergo remote interaction with further transition into highly ionized state. There is formation of optimal conformation in structure of the initial ion- exchangers. Significant increase of ionization of the ion-exchange resins occurs at molar ratio Amberlite IR120:AB-17-8 = 5:1. Significant increase of sorption properties is observed at this ratio due to mutual activation of ion-exchangers. The extraction rate of Nd3+ ions in 48 hours is 42.32%, and the extraction rate of Sc3+ ions is 38.06%. A possible reason for higher sorption of neodymium ions in comparison with scandium ions is maximum conformity of globes of internode links of Amberlite IR120 and AB-17-8 after activation to sizes of neodymium sulfate in an aqueous medium.

Nonlinear Faraday effect and spin noise in rare-earth activated crystals

The spin-noise spectroscopy (SNS) method implies high efficiency of conversion of the spin-system magnetization to the Faraday rotation angle. Generally, this efficiency cannot be estimated using the characteristics of the regular magneto-optical activity of a paramagnet. However, it may be drastically enhanced in systems with strong inhomogeneous broadening of the optical transitions. This enhancement leads to the giant spin-noise gain effect and previously allowed one to apply the SNS to rare-earth-activated crystals. We show that the nonlinear resonant Faraday effect can be used to measure the homogeneous width of the inhomogeneously broadened transition and, thus, to estimate the applicability of the SNS to this type of paramagnet. We present the theoretical description of the effect and perform measurements on intraconfigurational ($4f$-$4f$) transitions of the trivalent rare-earth ions of neodymium and ytterbium in fluorite-based crystals. The proposed experimental approach establishes new links between the effects of nonlinear optics and spin-noise characteristics of crystals with paramagnetic impurities and offers new ways of research in the physics of impurity crystals.

Spectrographic analysis of zinc-sulfate-magnesium-phosphate glass containing neodymium ions: Impact of silver–gold nanoparticles plasmonic coupling

Ascertaining plasmonic interaction induced by silver (Ag) and gold (Au) nanoparticles (NPs) in the amorphous system can open a new direction in photonics. In this outlook, various contents of Ag and Au NPs were incorporated into neodymium ions (Nd3+)-doped zinc-sulfate-magnesium-phosphate glasses via the melt-quenching method. The impact of Ag–Au plasmonic coupling on the structures and spectroscopic traits of the prepared glasses were evaluated. As-quenched samples were analyzed using XRD, HRTEM, Raman, absorption and photoluminescence (PL) spectrometer. The Judd-Ofelt (JO) theory was used to evaluate the spectroscopic quality and stimulated emission cross-section of the glasses. HRTEM micrographs verified the existence of Au and Ag NPs in the glass matrix with a mean size ranged 4.47–7.03 nm. The observed thirteen absorption bands centered around 326, 352, 430, 459, 473, 512, 52, 581, 627, 681, 744, 801, and 875 nm were corresponding to electronic transitions from the ground state (4I9/2) to the excited states of 4D7/2, 2D1/2+4D3/2+4D5/2, 2P1/2, 4G11/2, 2D3/2+2P3/2+2G9/2, 4G9/2+2K13/2, 4G7/2, 4G5/2+2G7/2, 2H11/2, 4F9/2, 4F7/2+4S3/2, 4F5/2+2H9/2 and 4F3/2 in Nd3+. Two surface plasmon resonance (SPR) bands assigned to Ag and Au NPs were probed at 442 nm and 503 nm. The addition of Au NPs causes the SPR band of Ag NPs to be red-shifted. The NIR PL bands at 878 nm, 1050 nm and 1322 nm were due to the 4F3/2 → 4I9/2, 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions, respectively. The PMZ1.5Nd0.5Ag0·1Au glass disclosed the highest bandwidth gain of 6.92, 17.05 and 9.10 ( × 10−23 cm3) corresponding to the 4F3/2 → 4I9/2, 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions. It was shown that the PL intensity of the studied glasses could be modified by varying Ag and Au NPs contents. The Ag–Au NPs plasmonic coupling inclusion inside the glass can be beneficial to develop versatile optical materials.