Solubility Of Zr Research Articles

Zr4+ Doping in Li4Ti5O12 Anode for Lithium‐Ion Batteries: Open Li+ Diffusion Paths through Structural Imperfection

One-dimensional nanomaterials have short Li(+) diffusion paths and promising structural stability, which results in a long cycle life during Li(+) insertion and extraction processes in lithium rechargeable batteries. In this study, we fabricated one-dimensional spinel Li4Ti5O12 (LTO) nanofibers using an electrospinning technique and studied the Zr(4+) doping effect on the lattice, electronic structure, and resultant electrochemical properties of Li-ion batteries (LIBs). Accommodating a small fraction of Zr(4+) ions in the Ti(4+) sites of the LTO structure gave rise to enhanced LIB performance, which was due to structural distortion through an increase in the average lattice constant and thereby enlarged Li(+) diffusion paths rather than changes to the electronic structure. Insulating ZrO2 nanoparticles present between the LTO grains due to the low Zr(4+) solubility had a negative effect on the Li(+) extraction capacity, however. These results could provide key design elements for LTO anodes based on atomic level insights that can pave the way to an optimal protocol to achieve particular functionalities.

Optimization of the Compositions of the High Strength Casting Aluminium Alloys Based on Nickel Eutectic

The phase composition of the AlNiMnFeSiZr system was analyzed with respect to new-generation heat resistant casting aluminum alloys based on a Ni-containing eutectic, which are strengthened by the Al3Zr (L12) nanoparticles. It is shown that the presence of iron and silicon considerably complicates the phase analysis compared with the AlNiMnFe base alloy. Alloys with low silicon content have a sufficiently good casting property, which enables fabrication of thin-walled castings, not inferior to AA356 alloy types widely used to cast complex shapes. Addition of silicon to the AlNiMnFe base alloy sharply deteriorates hot cracks. Silicon greatly decreases the solubility of Zr at (Al), which is reflected on hot brittleness of Al2%Ni1%Mn0,5%Fe-0,2%Zr system alloys.

Effects of fluorine on the solubilities of Nb, Ta, Zr and Hf minerals in highly fluxed water-saturated haplogranitic melts

The effect of fluorine on the solubilities of Mn-columbite (MnNb2O6), Mn-tantalite (MnTa2O6), zircon (ZrSiO4) and hafnon (HfSiO4) were determined in highly fluxed, water-saturated haplogranitic melts at 800 to 1000°C and 2kbar. The melt composition corresponds to the intersection of the granite minimum with the albite–orthoclase tieline (Ab72Or28) in the quartz–albite–orthoclase system (Q–Ab–Or), which is representative of a highly fluxed melt, from which high field strength element minerals may crystallize. The melt contains 1.7wt.% P2O5, 1.05wt.% Li2O and 1.83wt.% B2O3. The main purpose of this study is to examine the effect of F on columbite, tantalite, zircon and hafnon solubility for a melt with this composition. Up to 6wt.% fluorine was added as AgF in order to keep the aluminum saturation index (ASI, molar Al/[Na+K]) of the melt constant. In an additional experiment F was added as AlF3 to make a glass peraluminous. The nominal ASI of the melts are close to 1 for the minimum composition and approximately 1.32 in peraluminous glasses, but if Li is considered as an alkali, the molar ratio Al/[Na+K+Li] of the melts are alkaline (0.87) and subaluminous (1.09), respectively.The molar solubility products [MnO]∗[Nb2O5] and [MnO]∗[Ta2O5] are nearly independent of the F content of the melt, at approximately 18.19±1.2 and 43.65±2.5×10−4 (mol2/kg2), respectively for the minimum composition. By contrast, there is a positive dependence of zircon and hafnon solubilities on the fluorine content in the minimum composition, which increases from 2.03±0.03×10−4 (mol/kg) ZrO2 and 4.04±0.2×10−4 (mol/kg) HfO2 for melts with 0wt.%F to 3.81±0.3×10−4 (mol/kg) ZrO2 and 6.18±0.04×10−4 (mol/kg) HfO2 for melts with 8wt.%F. Comparison of the data from this work and previous studies indicates that ASI of the melt seems to have a stronger effect than the contents of fluxing elements in the melt and the overall conclusion is that fluorine is less important (relative to melt compositions) than previously thought for the control on the behavior of high field strength elements in highly evolved granitic melts. Moreover, this study confirms that although Nb, Ta, Zr and Hf are all high field strength elements, Nb–Ta and Zr–Hf are complexed differently in the melt.

An Experimental Investigation on the Solubility of Zr in Cu-Sn Alloys

An experimental investigation on the solubility of Zr in Cu-Sn alloy was conducted in a resistance furnace. The solubility of Zr in Cu-Sn alloy was determined by investigating the influence of different conditions such as the ratio of Cu-Sn alloy and temperature. The solubility of Zr in Cu-Sn alloy changes with the proportion of Cu and Sn, and it increases with the increasing of Cu content. The experimental temperature has a significant effect on the solubility of Zr in Cu-Sn alloy. The maximum solubility of Zr in Cu-Sn alloy is 6.2 mass % at 900 °C with the mass ratio of Cu : Sn = 8:2.

The influence of pH in metal/bromide catalyzed homogeneous aerobic autoxidation. Part 2. Precipitation of metals by aromatic acids

Two of the most common homogeneous aerobic oxidation catalysts are mixtures of Co/Mn/Br and Co/Mn/Zr/Br. They are especially effective in converting polyalkylbenzenes and naphthalenes to their respective aromatic acids using acetic acid as the solvent. Precipitation of the catalyst metals can occur when the product or by-product of these reactions is trimellitic (TMLA), pyromellitic (PMA), or hemimellitic acid (HMLA) (the 1,2,4-, 1,2,4,5, and 1,2,3- isomers respectively) by reaction of the metal(II) acetates to form insoluble metal carboxylic acid complexes. This can cause a decrease in rate of reaction and loss of selectivity to the aromatic acid. It is shown that this precipitation can be reduced or eliminated by reducing the pH, i.e. the acetate concentration, of the solvent. At a PMA concentration at which Co(II) and Mn(II) perchlorates or tetrafluoroborates do not react with PMA, the addition of increments of ammonium acetate results in increasing precipitation of the metals. The degree of precipitation is decreased by reducing the acetate concentration by using HBr rather than NaBr as the bromide source – the one exception being Co with HMLA. The presence of bromide itself decreases the degree of precipitation. In all cases, except one, the solubility of Co(II), Mn(II), and Zr(IV) increases with increasing water content in acetic acid. The exception is Co(II) with HMLA where the solubility first decreases with water content, up to ∼ 15wt%, and increases thereafter. The solvent system definition of acids and bases is used to rationalize the results in acetic acid/water mixtures to that observed in water.

Isothermal section of Al–Ti–Zr ternary system at 1273K

Abstract Phase equilibria in Al–Ti–Zr ternary system at 1273 K were experimentally investigated through alloy sampling combined with electron probe micro-analyzer (EPMA) and X-ray diffraction (XRD). No ternary compound was detected. Experimental results show that there is a continuous solid solution β(Ti, Zr) which dissolves up to 25.5 at.% Al, and Ti can substitute Zr in most Al–Zr binary intermediate phases to a certain degree while the maximum solubility of Zr in α 2 (Ti 3 Al) and γ(TiAl) reaches up to 25 at.% and 9 at.%, respectively. The isothermal section consists of 16 single-phase regions, 26 two-phase regions and 14 three-phase regions.

Zircon‐bearing, crystallized melt inclusions in peritectic garnet from the western Adirondack Mountains, New York State, USA

AbstractCrystallized melt inclusions (MI) occur in garnet from metapelitic gneiss extracted from a hydroelectric plant on the Black River at Port Leyden, NY (western Adirondack Highlands). The garnet host grains are small (0.5–1.0 mm), euhedral neoblasts that formed peritectically during biotite melting accompanying the Ottawan phase of the Grenville Orogeny. The crystallized MI are typically 10–25 μm in diameter and occur randomly in garnet. Nearly all of the crystallized MI observed contain a relatively large (3–15 μm), often euhedral, zircon grain surrounded by finer‐grained (some <1 μm) phases with energy dispersive X‐ray spectra consistent with biotite, K‐feldspar, quartz, and albite. The inclusions are similar in size and composition to those described in garnet from other migmatites and are similarly interpreted as crystallized anatectic melt. Low Zr solubility in silicate melt indicates that the large zircon grain in each inclusion must be a trapped solid. It is inferred that micrometer‐scale droplets of anatectic melt chemically adhered to occluded zircon grains in biotite while peritectic garnet grew around them.

Zircon solubility in aqueous fluids at high temperatures and pressures

The depletion of high field strength elements such as Zr, Nb and Ta is a characteristic feature of arc magmas and it has been attributed to a low solubility of these elements in slab-derived aqueous fluids. We have determined zircon solubility in aqueous fluids up to 1025°C and 20kbar by in situ observation of dissolving zircon grains in the hydrothermal diamond anvil cell. Zircon solubilities in H2O with silica activity buffered by quartz are very low, from 1.0 to 3.3ppm Zr, and weakly increase with temperature and pressure. Experimental results were fitted to the following fluid density model:logc(±0.10)=(3.45±0.92)-(3803±1098)T-1+(1.52±0.63)logρwhere c is the Zr concentration in the fluid (ppm by weight), T is temperature (K) and ρ is the fluid density (gcm−3). An additional experiment with a saline fluid (15wt.% NaCl) revealed an increase in zircon solubility by a factor of 3 (4.8±1.6ppm Zr at 890°C and 14kbar) whereas addition of 4.5wt.% albite as solute increased solubility by about a factor of 5. The Zr solubility at the forsterite–enstatite silica buffer appears to be slightly higher than that at the quartz buffer and it further increases at baddeleyite saturation (48±15ppm Zr at 930°C and 16kbar). These observations are consistent with the stability of zircon relative to ZrO2+SiO2 and suggest that Zr–Si complexes are not abundant in the fluid. During slab dehydration, the Zr content in the aqueous fluid is predicted to be 1–4ppm. Mass balance calculations imply that the high field strength element concentrations in primary arc melts will slightly decrease due to the dilution effect of infiltrating fluid. By contrast, mobile lithophile elements are predicted to increase their abundances in the melt by orders of magnitude. Our results suggest that the high abundance of large ion lithophile elements relative to high field strength elements in arc magmas is related to different solubilities of these elements in aqueous fluids migrating from the slab to the magma source regions.

Experimental investigation of phase equilibria in the Co–Si–Zr ternary system

The phase equilibria in the Co–Si–Zr ternary system were investigated by means of back-scattered electron (BSE), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Two isothermal sections of the Co–Si–Zr ternary system at 1273 and 1373K were experimentally established, and the compositions of the two ternary compounds (Zr5Co8Si9 and Zr4Co4Si7) were confirmed. The isothermal sections of the system at 1273 and 1373K respectively consist of 29 and 30 three-phase regions, and also six ternary compounds was found in both two isothermal sections. The solubility of Zr in the intermediate and solution phases (i.e. αCo2Si, αCoSi, CoSi2, αCo and εCo) at the Co–Si side is extremely small, whereas the situation of Si in the Co-rich corner (especially for Co23Zr6 and Co2Zr phases) is reverse.

Isothermal section of Dy-Zr-Si ternary system at 773 K

The isothermal section of the phase diagram of the Dy-Zr-Si ternary system at 773 K was determined by X-ray diffraction (XRD) analysis, metallographic analysis, and scanning electron microscopy (SEM) with energy-dispersive spectrometer (EDS) analysis. The isothermal section consists of 13 single-phase regions, 23 two-phase regions, and 11 three-phase regions. The solubilities of Zr in Dy, Dy5Si4, Dy5Si3, DySi, DySi2, DySi1.67, and Dy in Zr, Zr2Si, Zr3Si2, Zr5Si4, ZrSi, and ZrSi2 were determined at 773 K.

Dissolution of Zr in a mixture of H2SO4 and HNO3

Zr metal readily dissolved in a mixture of H2SO4 and HNO3. The solubility of Zr in a 10% mixture (96wt% H2SO4:61wt% HNO3=9:1 volumetric mixture) reached approximately 34g/L. It was found that NO2+ and H2SO4 are consumed to form NO2, NO+, and HSO4- upon the dissolution of Zr. Finally, two possible dissolution mechanisms are discussed.

Phase diagram of the Al–Dy–Zr ternary system at 773 K

Abstract X-ray powder diffractometry, scanning electron microscopy, optical microscopy and differential thermal analysis were used for constructing the isothermal section of the Al–Dy–Zr system in the whole compositional range at 773 K. The existence of 13 binary compounds and 1 ternary compound, i.e. Al3Zr, Al2Zr, Al3Zr2, AlZr, Al3Zr4, Al2Zr3, AlZr2, AlZr3, α - Al3Dy, Al2Dy, AlDy, Al2Dy3, AlDy2, and Al30Dy7Zr3 were confirmed. The ternary compound Al30Dy7Zr3 has AuCu3 structure (space group Pm3m) with lattice parameter of a = 0.4206 nm. The isothermal section consists of 17 single-phase regions, 32 binary-phase regions and 16 ternary-phase regions. The homogeneity of Dy in the binary compounds Al3Zr, Al2Zr, Al3Zr2, and AlZr2 is determined to be 2 at.%, 3 at.%, 4 at.%, and 2 at.% Dy, respectively. The homogeneity range of Dy in Zr is up to v7 at.% Zr. The solid solubility of Zr in the binary compounds Al3Dy, Al2Dy, and AlDy is determined to be 2 at.%, 26 at.%, and 3 at.% Zr, respectively.

수용액(水溶液)에서 지르코늄이온의 농도분포(濃度分布)

지르코늄은 우수한 내식성과 낮은 중성자 흡수단면적로 인해 원자로에서 구조재로 사용된다. 수용액의 pH에 따른 지르코늄을 함유한 화학종의 농도분포와 용해도의 변화를 구했다. 염산과 질산용액에서 지르코늄이온의 착물형성반응을 고려하여 무기산의 농도에 따른 농도분포를 해석하였다. 질산용액에서 Cyanex272에 의한 지르코늄 추출에 관한 문헌자료를 이용하여 지르코늄과 질산이온간의 Bromley매개변수를 구했다. 이와 같이 구한 매개변수값은 등온추출곡선의 계산이나 하프늄과의 분리인자 예측에 활용될 수 있다. Zirconium is used in nuclear reactors as a structural material due to its excellent corrosion resistance and to low neutron crosssection. Variation in the distribution and solubility of Zr(IV) with solution pH was obtained. Distribution of Zr(IV) containing species in HCl and <TEX>$HNO_3$</TEX> solution was analyzed by considering the complex formation of Zr(IV) species with the anion of the inorganic acid. Bromley interaction parameter between <TEX>$ZrO^{2+}$</TEX> and nitrate ion was estimated by using the reported data on the solvent extraction of Zr(IV) by Cyanex272 from <TEX>$HNO_3$</TEX> solution. This Bromley parameter can be utilized in calculating extraction isotherm of Zr(IV) and in predicting the separation factor between Zr(IV) and Hf(IV).

Microstructure, composition and P–T conditions of rutile from diamondiferous gneiss of the Saxonian Erzgebirge, Germany

The chemical composition and microstructure of rutile grains in a ultra-high pressure metamorphic gneiss of the Saxonian Erzgebirge, Germany have been studied by Raman spectroscopy, SEM, EMPA and TEM. Rutile inclusions in garnet contain free dislocations, iron-enriched dislocations and exsolved ilmenite lamellae, while subgrain boundaries are observed in rutile grains of the rock matrix. The previously reported α-PbO2 type TiO2 phase could not be confirmed by our TEM observations. On the basis of Zr solubility in the rutile and the presence of microdiamonds, minimum metamorphic peak conditions of 3.95GPa and 915°C are estimated.

Phase Diagrams of the Zr–Si–RE (RE=La and Er) Ternary Systems at 773 K (500 °C)

The isothermal sections of the phase diagram of the Zr–Si–RE (RE=La and Er) systems at 773 K (500 °C) have been investigated using X-ray power diffraction (XRD), scanning electron microscopy (SEM), and optical microscopy (OM) with the aid of metallographic analysis. The existences of 10 binary compounds, namely ZrSi2, α-ZrSi, α-Zr5Si4, Zr3Si2, Zr2Si, RESi2, RESi2–x , RESi, RE5Si4, and RE5Si3 have been confirmed in the Zr–Si–RE (RE=La and Er) systems, respectively. As for the reported binary compound RE3Si2, only La3Si2 has been observed in the Zr–Si–La system, whereas Er3Si2 was not found. No binary compound was found in the Zr–RE binary systems, and no ternary compound was found in the current ternary systems. None of the phases in Zr–Si–La system reveals a remarkable solid solution at 773 K (500 °C). However, the maximum solid solubility of Zr in Er, Er5Si3, Er5Si4, ErSi, ErSi1.67, and ErSi2 is determined to be approximately 12.0 at. pct, 2.4 at. pct, 3.0 at. pct, 3.3 at. pct, 2.2 at. pct, and 1.8 at. pct, respectively. The maximum solid solubility of Er in ErSi2 is approximately 1.8 at. pct. No remarkable solid solubility of the elements in any of the other phases has been observed.

Experimental Phase Diagram of the Al-Er-Zr Ternary System

The phase diagram of the Al-Er-Zr ternary system at 773 K has been experimentally investigated by means of x-ray powder diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscopy (SEM) with energy dispersive analysis (EDX). The existence of 13 binary compounds, i.e. Al3Zr, Al2Zr, Al3Zr2, AlZr, Al3Zr4, Al2Zr3, AlZr2, AlZr3, Al3Er, Al2Er, AlEr, Al2Er3 and AlEr2 was confirmed. It is proved that the phases Al3Zr5 and Al4Zr5 do not exist at 773 K. The isothermal section consists of 16 single-phase regions, 29 binary-phase regions and 14 ternary-phase regions. The maximum solid solubility of Zr in Al3Er, Al2Er, AlEr, Al2Er3 and Er is about 9, 14, 4.5, 5.4, and 12 at.% Zr, respectively. No remarkable solid solubility could be found in the other compounds of this ternary system at 773 K. No ternary compound is found in the present work.

Isothermal section of Mg–Zn–Zr ternary system at 345 ° C

Isothermal section of Mg–Zn–Zr ternary system at 345 ∘C has been determined by X-ray diffraction, differential scanning calorimetry and scanning electron microscopy assisted with energy dispersive X-ray spectroscopy using a series of Mg–Zn–Zr alloys. The results show that there exist three intermetallic compounds ZnZr, Zn 2Zr 3, (Mg,Zn) 2Zr, and a liquid phase in equilibrium with the α -Mg phase. The presence of two other three-phase regions in equilibrium, Liquid+MgZn+(Mg,Zn) 2Zr and MgZn+Mg 2Zn 3+(Mg,Zr)Zn 2, has also been confirmed. The addition of Zn can significantly increase the solubility of Zr and vice-versa in the α -Mg matrix.

Isothermal section of the Al–Dy–Zr ternary system at 773 K

The phase relations in the Al–Dy–Zr ternary system at 773 K have been investigated by X-ray powder diffraction (XRD) and scanning electron microscope (SEM) with energy disperse X-ray spectroscopy (EDX) in backscattered electron imaging (BSE) modes. The isothermal section at this temperature is featured with 17 single-phase regions, 32 two-phase regions and 16 three-phase regions. Besides, the ternary compound Al 30Dy 7Zr 3 has been confirmed to be existed. The maximum solid solubility of Zr in AlDy 2, Al 2Dy 3, AlDy, Al 2Dy and Al 3Dy at 773 K is determined to be 11.5 at.%, 7.8 at.%, 2.4 at.%, 22.5 at.% and 2.5 at.%, respectively.

Structural and microstructural changes in the zirconium–indium mixed oxide system during the thermal treatment

The zirconium–indium mixed oxide systems on both the zirconium- and the indium-rich side of the concentration range were prepared by co-precipitation from aqueous solutions of the corresponding salts, followed by washing and heat-treatment. The thermal behavior (up to 1000 °C) of the dried samples was examined by X-ray powder diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectrometry, differential thermal analysis and thermogravimetric measurements. The obtained results show that the increase in the amount of the second phase causes an increase of both the crystallization temperature of the amorphous precursors of ZrO 2, from 435 °C (0 mol.% of InO 1.5) to 476 °C (∼62 mol.% of InO 1.5), and of the topotactic transition temperature of cubic In(OH) 3 to cubic In 2O 3, from 259 °C (0 mol.% of ZrO 2) to 290 °C (∼25 mol.% of ZrO 2). The amorphous precursors of ZrO 2 phase exhibit an extended capability to incorporate In 3+ ions (more than 60 mol.%). With a rise in temperature the maximum solubility of In 3+ ions in the ZrO 2 lattice decreases from ∼55 mol.% in the crystallization products obtained after calcination at 400 °C to ∼10 mol.% after calcination at 1000 °C. The results of phase analysis indicate that the incorporation of In 3+ ions partially stabilized both the tetragonal and cubic ZrO 2 polymorphs. The maximum solubility of Zr 4+ ions in the starting In(OH) 3 lattice was estimated at ∼10 mol.%. Thermal treatment causes a small increase of Zr 4+ ion solubility limits, estimated at ∼15 mol.% in the cubic In 2O 3 lattice after calcination at 1000 °C. Precise lattice parameter measurements, by using Le Bail refinements of the powder diffraction patterns with added silicon as an internal standard, show that the incorporation of In 3+ ions caused a very small decrease of the cubic ZrO 2 lattice, while the incorporation of Zr 4+ ions had a negligible influence on the parameters of cubic In(OH) 3 and In 2O 3 lattices. The obtained results were compared with the results obtained for mixed oxides of zirconium and undersized trivalent metals (systems ZrO 2–Fe 2O 3, ZrO 2–Ga 2O 3, ZrO 2–Cr 2O 3 and ZrO 2–Al 2O 3).

Experimental determination of the phase equilibria in the Co–Fe–Zr ternary system

The phase equilibria in the Co–Fe–Zr ternary system were investigated by means of optical microscopy (OM), electron probe microanalysis (EPMA), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) on equilibrated ternary alloys. Four isothermal sections of the Co–Fe–Zr ternary system at 1300 °C, 1200 °C, 1100 °C and 1000 °C were experimentally established. The experimental results indicate that (1) no ternary compound was found in this system; (2) the solubility of Fe in the liquid phase of the Co-rich corner at 1300 °C is extremely large; (3) the liquid phase in the Zr-rich corner and the (Co,Fe) 2Zr phase form the continuous solid solutions from the Co–Zr side to the Fe–Zr side; (4) the solubility of Zr in the fcc (Co, Fe) phase is extremely small.