Dysprosium Chloride Research Articles

Electrochemical Behavior of Dysprosium Ion and Its Co-Electroreduction with Nickel Ions in the Molten KCl-NaCl-CsCl Eutectic

The electrochemical behavior of dysprosium ions, as well as dysprosium and nickel ion co-reduction, on inert tungsten electrodes and active nickel electrodes were studied in the eutectic KCl-NaCl-CsCl melt at a temperature of 823 K using the methods of cyclic and square-wave voltammetry and open circuit chronopotentiometry. The process of Dy3+ ions electroreduction was found to be reversible and to proceed within a single three-electron stage up to the polarization rate of 0.1 V/s. The increase in the polarization rate indicates a slower rate of the charge transfer, which causes the quasi-reversible character of the charge transfer. It is shown that when the KCl-NaCl-CsCl eutectic melt contains both nickel and dysprosium ions, the voltammetry curves at 823 K have a wave of nickel ion reduction at the potentials of −(0.22–0.28) V and a dysprosium ion reduction at the potentials of −(2.175–2.250) V relative to a chlorine-silver reference electrode. Apart from these waves, the voltammograms have two reduction waves at the potentials of −(1.9–1.95) V and −(2.05–2.1) V. These waves are associated with the reduction of dysprosium ions and their depolarization on metallic nickel, which was preliminary deposited on the tungsten electrode, as well as the formation of the intermetallic phases of dysprosium and nickel of various DyxNiy compositions. The (E-t) dependencies of the open circuit chronopotentiometry elucidate plateaus of the potential delay, which correspond to the dissolution of separate dysprosium and nickel intermetallic phases. Based on the results of the voltammetry changes and the chronopotentiometry of the open circuit, a series of electrochemical syntheses were performed in the potentiostatic regime at the potentials of −(1.7–2.1) V. The intermetallic phases of DyNi5, DyNi3 and DyNi2 were obtained at a definite ratio of the dysprosium and nickel chloride concentrations in the KCl-NaCl-CsCl eutectic melt and at a temperature of 823 K. The synthesized intermetallic samples were characterized by X-ray diffraction and scanning electron microscopy.

Dy4, Dy5, and Ho2 Complexes of an N3O2 Aminophenol Donor: A Dy5-µ3-Peroxide Single Molecule Magnet.

The reactivity of the new flexible potentially pentadentate N3O2 aminophenol ligand H4Lr (2,2'-((pyridine-2,6-diylbis(methylene))bis(azanediyl))diphenol) towards different dysprosium salts and holmium(III) nitrate was investigated. Accordingly, this reactivity seems to greatly depend on the metal ion and salt employed. In this way, the reaction of H4Lr with dysprosium(III) chloride in air leads to the oxo-bridged tetranuclear complex [Dy4(H2Lr)3(Cl)4(μ3-O)(EtOH)2(H2O)2]·2EtOH·H2O (1·2EtOH·H2O), while the same reaction just changing the chloride salt by the nitrate one renders the peroxo-bridged pentanuclear compound [Dy5(H2Lr)2(H2.5Lr)2(NO3)4(µ3-O2)2]·2H2O (2·2H2O), where both peroxo ligands seem to come from the fixation and reduction of atmospheric oxygen. However, if holmium(III) nitrate is used instead of dysprosium(III) nitrate, no evidence of a peroxide ligand is observed, and the dinuclear complex {[Ho2(H2Lr)(H3Lr)(NO3)2(H2O)2](NO3)} 2.5H2O (3·2.5H2O) is isolated. The three complexes were unequivocally characterized by X-ray diffraction techniques, and their magnetic properties were analyzed. Thus, while the Dy4 and Ho2 complexes do not show magnet-like behavior even in the presence of an external magnetic field, 2·2H2O is a single molecule magnet, with an Ueff barrier of 61.2 K (43.2 cm-1). This is the first homonuclear lanthanoid peroxide SMM, which also shows the highest barrier among the reported 4f/3d peroxide zero field SMMs to date.

Atomic and Ionic Luminescence of Dysprosium During Sonolysis by a Single Moving Bubble in a Colloidal Suspension of Nanoparticles Containing Dysprosium Chloride

Atomic and Ionic Luminescence of Dysprosium During Sonolysis by a Single Moving Bubble in a Colloidal Suspension of Nanoparticles Containing Dysprosium Chloride

A DyIII Complex of a Pentadentate Schiff Base with Field-Induced Single-Ion Magnet Behaviour

The influence of the solvent in the reaction of dysprosium(III) chloride hydrate with the N3O2 ligand H2L (2,6-bis(2-hydroxyphenyliminomethyl)pyridine) was studied To this end, the new mononuclear chloride complex [Dy(L)Cl(H2O)2] (1) was isolated in absolute ethanol as solvent, without any evidence of the hydrolysis of the ligand. This clearly contrasts with previous results, where a similar reaction in methanol proceeds with the partial hydrolysis of the Schiff base, and the formation of a new hemiacetal donor to yield [Dy(HL’)2)][Dy(L)(Cl2)] (H2L’ = (6-(2-hydroxyphenyliminomethyl)-2-methoxyhydroxymethyl)pyridine). The single crystal X-ray structure of the chloride complex 1 shows that the DyIII ion is octacoordinated in a highly distorted N3O4Cl environment between triangular dodecahedral and biaugmented trigonal prisms. The full magnetic characterisation of 1 shows that it presents field-induced single ion magnet behaviour, with a thermal energy barrier Ueff of 113.5 K, which is the highest among dysprosium complexes derived from H2L.

A Tetranuclear Dysprosium Schiff Base Complex Showing Slow Relaxation of Magnetization

A tetranuclear dysprosium Schiff base complex was isolated by reacting dysprosium chloride with 2-hydroxy-3-methoxybenzaldehyde and 2-(aminomethyl)pyridine in-situ under basic conditions. The isolated Dy(III) complex was characterized by elemental analyses, single crystal X-ray diffraction and molecular spectroscopy. The complex crystallizes in the triclinic space group P-1 with unit cell parameters of a = 10.2003 (4), b = 13.8602 (5), c = 14.9542 (6), α = 94.523 (3), β = 109.362 (4), and γ = 99.861 (3). The magnetic properties of 1 have been investigated by DC and AC susceptibility measurements. The DC measurements reveal weak exchange coupling of antiferromagnetic nature. In the AC measurement, the complex shows a slow relaxation of magnetization in the absence of an external magnetic field.

Speciation of dysprosium in molten LiCl–KCl–CsCl eutectic: An electrochemistry and spectroscopy study

Speciation and behavior of dysprosium (III) chloride in the ternary low melting LiCl–KCl–CsCl eutectic was studied by electrochemistry and spectroscopy techniques. Electronic absorption spectra of Dy(III) ions were recorded at 723–1023 K. Prolonged holding of relatively concentrated DyCl3 solutions in the melt resulted in a very subtle decomposition of Dy(III) to Dy(II) chloro-species. Cathodic reduction of Dy(III) ions on inert molybdenum electrode was studied at 623–973 K in the inert atmosphere by transient electrochemical techniques (cyclic and square-wave voltammetry). In dilute solutions the cathodic reduction of Dy(III) ions was irreversible, proceeded in one stage, and was controlled by the charge transfer. The diffusion coefficients of [DyCl6]3- complex ions in fused LiCl–KCl–CsCl eutectic were determined at different temperatures. The apparent standard potential of Dy(III)/Dy couple was determined by the open-circuit potentiometry and the principal thermodynamic properties of dysprosium trichloride in fused solvent were calculated.

Dilution effect on the slow relaxation of a luminescent dysprosium Metal-Organic Framework based on 2,5-dihydroxyterephthalic acid

A new dysprosium based Metal-Organic Framework with {[Dy(dhbdc)1.5(DMF)2]·DMF}n formula has been obtained from solvothermal reaction with 2,5-dihydroxyterephthalic acid ligand and dysprosium chloride. This coordination polymer has been characterized and its crystal structure has been solved by X-ray diffraction methods elucidating a three-dimensional network. Magnetic studies of this compound reveal the existence of weak antiferromagnetic interactions among the metal ions with θ value of −0.26 K. Dynamic ac magnetic susceptibility measurements were carried out under an external dc field of 1 kOe, highlighting that at high frequencies two relaxation processes can be observed. However, when studying the diamagnetically diluted analogue 1Y, a single relaxation process was detected highlighting the effect of the weak but not negligible exchange interactions. Finally, photoluminescence measurements were performed at different temperatures with the aim of getting a more representative characterization of the emissive performance of the material for potential applications in lighting and thermometry.

Magnetism‐Structures Relationship of 3,5‐Heptanedione Dy(III) SMMs Based on the Nitrogen‐Containing Auxiliary Ligand

AbstractTwo new 3, 5‐heptanedione (β‐diketonate) dysprosium complexes, namely, [Dy(L)3(phen)] (1) and [Dy(L)3(tmphen)] (2), have been designed and isolated by reactions of 3, 5‐heptanedione with dysprosium chloride and auxiliary ligand under room temperature (L=3, 5‐heptanedione, phen=1, 10‐phenanthroline, tmphen=3, 4, 7, 8‐tetramethyl‐1, 10‐phenanthroline). X‐ray crystallographic analysis reveals that complexes 1 and 2 are mononuclear, and the Dy(III) ions are eight coordinated forming the square‐anti‐prismatic geometry. Complexes 1 and 2 were characterized by various means including elemental analysis, IR and UV spectroscopy. Magnetic studies indicate that both complexes 1 and 2 are single‐molecule magnets (SMMs) under zero dc field. Notably, the auxiliary ligand plays an essential role in regulating their magnetism, which result in the essential magnetism difference between complexes 1 and 2.

The self-assembly of DyF3 nanoparticles synthesized by chloride-based route

The series of DyF3 nanoparticles was synthesized for the first time by a chloride-based route, using the water-soluble dysprosium chloride hexahydrate as a precursor. The synthesized nanoparticles have sizes of 3 to 7 nm, which is the smallest reported size for DyF3 nanoparticles. The influence of precursor concentration in an aqueous solution prior to the chemical reaction on the size of nanoparticles was studied. The influence of microwave-assisted hydrothermal treatment was also studied. The analysis of transmission electron microscopy (TEM) data revealed no correlation between the size of synthesized nanoparticles and the concentration of the aqueous solution. The AC/DC magnetic susceptibility of DyF3 nanoparticles was measured. The dipolar ferromagnetic transition for this sample was not observed down to 1.8 K that can be possibly explained by onset of superparamagnetism. The self-assembly of DyF3 nanoparticles was observed for the first time by analysis of XRD and TEM data and the evidence of superlattice formation along (020) and (210) lattice planes over the size of 20–30 nm (4–5 nanoparticles) was obtained.

Impact of neutron irradiation on the structural and optical properties of PVP/gelatin blends doped with dysprosium (III) chloride

Polymer composites of a system of Polyvinylpyrrolidone (PVP)/gelatin/DyCl3·6H2O were prepared in three groups that have different concentrations of PVP/gelatin contents to study the effect of neutron irradiation on their structural and optical properties. Results showed that the interaction of neutrons led to various complex phenomena, mainly bond breaking, main chain scission and intermolecular cross-linking. These processes introduced defects inside the material that were responsible for the changes in their optical and structural properties. All the calculated parameters were found to be dependent on the irradiation fluence in a uniform manner that makes these materials excellent candidates in the applications of dosimetry and radiology. Moreover, the sensitivity of the three groups of composites to the irradiation doses was found to be different. The variation in the structure of the composite group that contains the least PVP content was found to be less significant; hence, these materials were more stable against high doses that make them suitable for high radiation dose applications.

Evaluation of supercapacitive and magnetic properties of Fe3O4 nano-particles electrochemically doped with dysprosium cations: Development of a novel iron-based electrode

In this research, a novel one-pot fabrication platform was developed for the preparation of Dy3+-doped iron oxide nanoparticles (Dy-IONPs). In the procedure, Dy-IONPs are electro-deposited from an additive-free aqueous mixed solution of iron(III) nitrate, iron(II) chloride and dysprosium chloride salts through applying a current density of 10mAcm–2 for 30min. The analytical data obtained from X-ray diffraction (XRD), field emission electron microscopy (FE-SEM) and energy-dispersive X-ray (EDX) confirmed the deposited Dy-IONPs to be composed of magnetite nanoparticles (size≈20nm) containing about 10wt% of Dy3+ cations as the doping agent. The electrochemical data obtained through galvanostatic charge-discharge (GCD) tests showed that Dy-IONPs provide specific capacitances values of as high as 202 and 111Fg−1at the discharge loads of 0.5 and 5Ag−1, respectively, and reveal capacity retentions of 93.9% and 77.2% after 2000 GCD cycling. These could be held as proof that the electro-synthesized Dy3+-doped Fe3O4 NPs are suitable candidates for use in supercapacitors. Furthermore, the results of vibrating sample magnetometer (VSM) measurements indicated better superparamagnetic behavior of the Dy-IONPs (Mr = 0.34emug–1 and HCi= 6.25G) as opposed to pure IONPs (Mr = 0.95emug–1 and HCi= 14.62G), which originates from their lower Mr and Hci values. Based on the results, the proposed electro-synthesis method offers a facile procedure for the preparation of high- performance metal-ion-doped IONPs.

Electrical conductivity of molten lithium chloride – dysprosium(III) chloride system compared to other alkali metal chloride – dysprosium(III) chloride and lithium chloride – lanthanide(III) chloride systems

Electrical conductivity of not investigated yet molten binary system LiCl-DyCl3 has been determined in the temperature range 823–1073K. Temperature dependence of specific conductance of melts was fitted by the second order polynomial and molar conductivity by classical Arrhenius equation. The results were discussed in combination with the electrical conductivity data for other alkali metal chloride – dysprosium chloride and lithium chloride – lanthanide chloride melts. It was found that the lithium system differs from other alkali metal ones particularly in deviation from additivity rule (the maximum of deviation is significantly shifted to DyCl3-rich melt) and dependency of molar conductivity on the melt composition (for the lithium system conductivity regularly decreases with the increase of DyCl3 content whereas for other systems there are maxima of the first derivative of this dependence at xDyCl3=0.6–0.7), most likely due to the reduction of stability of dysprosium complex species by lithium cation.

Models of the nearest surrounding of ions in aqueous solutions of dysprosium chloride

Structural organization models are developed using radial distribution functions obtained earlier via XRD analysis for aqueous solutions of dysprosium chloride over a wide range of concentrations under standard conditions. The optimum variants are selected by calculating the theoretical functions for each model and comparing how they agree with experimental functions. Quantitative characteristics of the nearest surrounding of Dy3+ and Cl– ions, e.g., coordination numbers, interparticle distances, and varieties of ion pairs, are established. It is shown that the average number of water molecules in the first coordination sphere of a cation falls from 8.5 to 6 as the concentration grows; the structure of the system over the range of concentrations is determined by noncontact ion associates.

OBTAINING OF NICKEL AND COBALT COATING ALLOYS BY DIFFUSION SATURATION WITH DYSPROSIUM IN LiCl–KCl–DyCl3 MELT

A gravimetric method was used to study the influence of process temperature (Т) and duration (τ) on the specific mass variation of nickel and cobalt specimens during their currentless diffusion saturation with dysprosium in a liquated eutectic mixture of lithium and potassium chlorides with dysprosium chloride added (5 wt.%). The experimental results allowed to calculate the mathematical dependences Р(τ) for nickel specimens in the temperature range of Т = 773÷973 К at τ = 1÷8 h, and for cobalt specimens in the temperature range of Т = 873÷973 К at τ = 1÷7 h. Their analysis showed that the solid-state diffusion is the rate-controlling step of currentless dysprosium transfer to Ni and Co specimens. The composition of coating alloys was studied using the X-ray fluorescence spectrometer, X-ray microanalyzer, and scanning microscope. It was found that under experimental conditions, the coating forming on the nickel substrate surface consists of one structural zone, but when substrate material is cobalt, the coating consists of two structural zones. This is consistent with available literature data on the alloying of similar bimetallic systems.

Coordination of ions in aqueous solutions of dysprosium chloride according to the X-ray diffraction data

Aqueous solutions of dysprosium chloride in a wide concentration range are studied by X-ray diffraction analysis under standard conditions. The scattered X-ray radiation intensity curves are characterized by prepeaks at low values of the wave vector. Their interpretation and an analysis of changes at different concentrations are performed. The structure of concentrated solutions is formed due to interionic interactions of different types. On the contrary, dilute solutions are characterized by the determining role of the quasi-tetrahedral structure of the solvent. The prepeaks are also observed on the intensity curves of dilute solutions, indicating that these solutions retain the “long-range” ordering.

Electrochemical reduction of dysprosium ions in a chloride melt at various electrodes

The mechanism of electroreduction of dysprosium chloride complexes on silver and tungsten electrodes is studied by linear and cyclic voltammetry in an equimolar NaCl-KCl melt at 973 K, and the kinetic parameters of the process are calculated. The diffusion coefficient of dysprosium ions is calculated. In contrast to a tungsten electrode, the electroreduction on a silver electrode is complicated by alloy formation with the cathode material.

Preparation and photocatalytic activity of Nd doped ZnO nanoparticles

As an important II-VI semiconductor, zinc oxide has attracted a great deal of attention as a photocatalytic material. The quick recombination of charge carriers is the main factor influencing the photocatalytic activity of ZnO. In order to improve the photocatalytic activity, different kinds of ions were doped into ZnO by different methods to inhibit the recombination of photoinduced electrons and holes. Nd doped ZnO study is mainly on the optical performances. However, the Nd–ZnO nanoparticles have reported little work on the photodegradation of organic contaminants under visible light irradiation. In this paper, the mainly research is focused on the preparation process and removal properties of organic pollutants Cong red from the wastewater using the Nd doped zinc oxide nanoparticles. The proposed research investigates the Nd doped zinc oxide nanoparticles with varied Nd content that are important in understanding the structure, morphology and the photocatalytic performances. The undoped and Nd doped zinc oxide nanoparticles were prepared by sol–gel technique using zinc acetate dehydrate and dysprosium chloride and neodymium chloride as precursor. X-ray diffraction (XRD) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used to examine the morphology and microstructure of the nanoparticles. The analysed results indicate that the nanoparticles have a pure hexagonal wurtzite ZnO structure with the good crystal quality and the Nd ion was in a 3+ charge state in the crystal lattice of ZnO. The performance of Nd doped ZnO powders as efficient photocatalyst was further demonstrated in the degradation of Cong red (CR) under visible light irradiation. The Nd doped ZnO nanoparticles show good photocatalytic activity during the degradation of CR under visible light. It was found that an appropriate amount of Nd dopant can greatly increase photocatalytic activity and the sample with 4%Nd doping exhibits the highest photocatalytic efficiency.

Prediction of hydrogen chloride pressure to avoid hydrolysis in dehydration of dysprosium trichloride hexahydrate (DyCl3.6H2O)

The prevalent metal extraction processes for most reactive metals and their alloys are fused salt electrolysis and metallothermic reduction. The feed material for both of these processes is the anhydrous chloride of the metal under consideration. Dehydration of the feed material is then a critical step in the production of most reactive metals and requires rigorous thermodynamic analysis. Thermodynamic data for most of the reactive metal chloride hydrates have not been measured. Improper dehydration of the metal chloride may lead to a prohibitive amount of hydroxychloride, oxychloride, and finally oxide. To prevent hydrolysis a certain pressure of hydrogen chloride is required to be maintained to supress hydrolysis. An estimation and prediction model is presented for the vapour pressures of reactive metal chloride hydrates in an attempt to deduce the conditions necessary for dehydration to proceed without hydrolysis. Thermodynamic data including heat capacities, standard entropies, and standard enthalpies are estimated/predicted for all conceivable intermediate hydrate compounds. Estimations are based on published data as well as trends proven in similar systems. The thermodynamic estimations and predictions are presented for dysprosium chloride hydrates.Les procédés courants d’extraction de métal des métaux les plus réactifs et de leurs alliages sont l’électrolyse en bain de sel fondu et la réduction métallo-thermique. Le matériel d’alimentation de ces deux procédés est le chlorure anhydre du métal considéré. La déshydratation du matériel d’alimentation est donc une étape critique dans la production des métaux les plus réactifs et requiert une analyse thermodynamique rigoureuse. Les données thermodynamiques de la plupart des hydrates de chlorure du métal réactif n’ont pas été mesurées. Une déshydratation inappropriée du chlorure de métal peut produire une quantité excessive d’hydroxychlorure, d’oxychlorure et finalement d’oxyde. Afin d’empêcher l’hydrolyse, on doit maintenir une certaine pression de chlorure d’hydrogène. On présente un modèle d’estimation et de prédiction des pressions de vapeur des hydrates de chlorure de métal réactif, dans une tentative de déduire les conditions nécessaires pour que la déshydratation se produise sans hydrolyse. On a estimé ou prédit les données thermodynamiques incluant les capacités calorifiques, les entropies standards et les enthalpies standards de tous les composés hydrates intermédiaires concevables. Les estimations sont basées sur les données publiées ainsi que sur les tendances démontrées dans des systèmes similaires. On présente les estimations et les prédictions thermodynamiques des hydrates de dysprosium chlorure.

The Electroreduction of Gadolinium and Dysprosium Ions in Equimolar NaCl-KCl Melt

The mechanism of rare earth metals (Gd and Dy) chloride complexes electroreduction on the tungsten electrode in equimolar NaCl-KCl melt at 973 K has been studied by linear and cyclic voltammetry. Some kinetic parameters of processes were calculated. It was shown that the tungsten electrode was indifferent to gadolinium and dysprosium which were reduced on the surface. We found that the discharge mechanism of gadolinium and dysprosium chloride complexes was described by three-electron step when the steady-state conditions of polarization were limited by the mass transfer stage. The conditions of nonstationary polarization made the slowness of the charge transfer stage. The diffusion coefficient of gadolinium and dysprosium ions was calculated, the diffusion coefficient of GdCl3-6 ions was (0.9 ± 0.2) × 10-5 cm2.s-1, and for DYCI3-6 ions, it was (1.60 ± 0.2) × 10-5 сm2.s-1.

DyPO4 flower-like superstructures and macroporous microstructures from dysprosium-based coordination polymer wires

Abstract This article presents a facile approach about the designed synthesis of one-dimensional (1D) dysprosium-based coordination polymer wires under solvothermal conditions with dysprosium chloride and tributyl phosphate (TBP) as starting materials. The wires are in the length of several hundreds of micrometers and diameter in the range of 0.4–2 μm. Time-dependent results revealed that the coordination polymer wires were not stable and evolved into three-dimensional (3D) flower-like tetragonal DyPO 4 superstructures with the prolonging of reaction time. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), energy disperse spectroscopy (EDS), thermogravimetric analysis (TG) and differential thermal analysis (DTA) were employed to characterize the samples. Interestingly, with the assistance of lauryl sodium sulfate, rice-like macroporous hexagonal DyPO 4 microstructures with a BET surface area of 2.13 m 2 /g were successfully fabricated. A possible formation mechanism for the morphology evolution of the DyPO 4 superstructures was also discussed. Magnetic measurement revealed that the products were antiferromagnetic.