Fe Sb System Research Articles

Strain-tuned magnetic properties in (Ga,Fe)Sb: First-principles study* *Project supported by the National Natural Science Foundation of China (Grant Nos. 11764032 and 11665018).

In view of the importance of enhancing ferromagnetic (FM) coupling in dilute magnetic semiconductors (DMSs), the effects of strain on the electronic structures and magnetic properties of (Ga,Fe)Sb were examined by a first-principles study. The results of the investigation indicate that FeGa substitution takes place in the low-spin state (LSS) with a total magnetic moment of 1μ B in the strain range of –3% to 0.5%, which transitions to the high-spin state (HSS) with a total magnetic moment of 5μ B as the strain changes from 0.6% to 3%. We attribute the changes in the amount and distribution of the total moment to the influence of the crystal field under different strains. The FM coupling is strongest under a strain of about 0.5%, but gradually becomes weaker with increasing compressive and tensile strains. The magnetic coupling mechanism is discussed in detail. Our results highlight the important contribution of strain to magnetic moment and FM interaction intensity, and present an interesting avenue for the future design of high Curie temperature (T C) materials in the (Ga,Fe)Sb system.

Interaction of exogenous refractory nanoparticles of Al2O3 and MgAl2O4 with nonferrous metal impurities in iron melts

The exogenous refractory nanoparticles is proposed for refining iron-based melts from nonferrous metal impurities. Investigated the heterophase interaction of Al2O3 and MgAl2O4 nanoparticles with Sb/Sn/Cu and showed that the degree of removal of nonferrous metal impurities was in the Fe-Sb system up to 30 rel.%, in the Fe-Sn system up to 29 rel. % and in the Fe-Cu system up to 23 rel. %. The existence of refractory nanoparticles in a liquid metal was proved by studying the structural properties of the melt. In the melts, after the introduction of the nanoparticles, inversion of the temperature coefficient of surface tension is observed, as well as multidirectional change depending on the nature of the nanoparticles and the holding time during interfacial interaction. Decompression and compression of the melts after the introduction of nanoparticles and the multidirectional nature of the dependences of properties indicate a possible change in the cluster structure of liquid metal.

Time Dependence of the Resistivity of the Fe-Sb System at Room Temperature

In this paper, the synthesis, resistivity measurement, and X-ray diffraction of the Fe-Sb system are reported. The method of synthesis of the Fe-Sb system, which instigates the formation of the FeSb2 and FeSb phases between Fe grains at the interface, was found to cause a decrease in resistivity. The sample produced an anomalous result for resistivity behavior at room temperature, where a time-dependent change in the electrical resistivity was observed. This change can be expressed by the exponential function of time.

Enthalpies of mixing in binary Fe–Sb, Ce–Fe and ternary Ce–Fe–Sb liquid alloys

Abstract The enthalpies of mixing in liquid alloys in the binary Fe–Sb, Ce–Fe and ternary Ce–Fe–Sb systems were determined over a wide range of composition by means of isoperibolic calorimetry in the temperature range 1600–1830 K. The minimum values of the integral enthalpy of mixing (ΔH min) were determined to be (−2.32 ± 0.22) kJ · mol−1 at x Sb = 0.5 in the Fe–Sb system, and (−0.97 ± 0.19) kJ · mol−1 at x Ce = 0.35 in the Ce–Fe system. The enthalpies of mixing in liquid ternary Ce–Fe–Sb alloys were found to increase smoothly from the binary boundary systems Ce–Fe and Fe–Sb towards the Ce–Sb system, reaching the minimum value of (−107.5 ± 3.6) kJ · mol−1 in the vicinity of the phase CeSb.

An electrochemical study of Fe1.18Sb1.82 as negative electrode for sodium ion batteries

The mechanism of the electrochemical reaction between FeSb2 and sodium in sodium half cells has been very recently reported [1,L.Baggetto, H.-Y. Hah, C. E. Johnson, C. A. Bridges, J. A. Johnson, G. M. Veith, Phys.Chem.Chem.Phys. 16 (2014) 9538]. Its electrochemical activity, initially limited, seems based on an incomplete desodiation of Na3Sb formed during the first discharge and the occurrence of a “Fe4Sb” alloy inactive in the cell. However, no more than two charge/discharge cycles were shown. With this work we shed light on the sodium ion battery electrode properties of another solid in the Fe-Sb system (Fe1.18Sb1.82). Capacity retention properties in two different electrolyte configurations containing NaClO4 as sodium salt and by setting two cycling voltage limits are shown. A discussion about the impact of an additive such as fluoroethylene carbonate (FEC) in the electrode performance is assisted by applying electrochemical impedance spectroscopy on the electrode/electrolyte interfaces. When the additive is not present in the electrolyte, the occurrence of a surface film onto the electrode particles due to the electrolyte decomposition is noticed at low voltage values (0.3V vs. Na/Na+). Further discharge leads to the growth of this layer and conversely to decrease in the charge transfer resistance as several well dispersed metallic products are present in the discharged electrode. Upon charging, the film is firstly decomposed and/or dissolved and the charge transfer resistance increases. Beyond 1.05V vs. Na/Na+, a second film, of a different nature from the first one appears onto fresh antimony or FexSby particles formed from desodiation of poorly crystallized Na3Sb. When FEC is added to the electrolyte, the interface is influenced at each stage of the discharge or the charge. FEC suppresses the growth of the surface film at low voltages and decreases the charge transfer resistance at any stage. Upon charging beyond 1.05V vs. Na/Na+, the surface films are less resistive than in the absence of FEC. Therefore, the additive has a constructive effect on the cell capacity retention upon cycling. Finally setting the lowest limit voltage at 0.2V vs. Na/Na+ does not result in an improvement in the capacity retention upon cycling, but halves the capacity values compared to the ones obtained at a 0V vs. Na/Na+ limit voltage.

Thermodynamic assessment of the Co–Fe–Sb system

The Co–Fe–Sb ternary system is critically assessed by CALPHAD (CALculation of PHAse Diagram) technique in the present work. The NiAs-type structure phase β-(Co,Fe)Sb with a wide non-stoichiometric range is described by three sublattices, (Sb)1/3(Co,Fe,Va)1/3 (Co,Fe,Va)1/3, following the extension of the sublattices of the phases β(CoSb) and β(FeSb) in the related binaries. The intermetallic compounds ζ(Co,Fe)Sb2 and η(Co,Fe)Sb3 are treated as linear stoichiometric compounds. The liquid, γ(A1)-Fcc_A1, α(A2)-Bcc_A2 and ε(A3)-Hcp_A3 phases are assumed to be substitutional solutions. The Rhombo_A7 phase is considered as the pure Sb phase. The order/disorder transformation between α(A2)-Bcc_A2 and α′(B2)-Bcc_B2 phases is described by a two-sublattice model (Co,Fe,Sb)0.5(Co,Fe,Sb)0.5. A set of self-consistent thermodynamic parameters of the Co–Fe–Sb system is obtained to fit satisfactorily a large amount of experimental data from literature. In the mean while, the Fe–Sb binary system is re-optimized critically.

Thermodynamic description of the Er–Fe–Sb system

The Er–Fe, Er–Sb and Er–Fe–Sb systems were optimized by means of the CALPHAD (CALculation of PHAse Diagram) technique. The solution phases, liquid, bcc, fcc, hcp and rhom, were described by the substitutional solution model. The binary compounds, Er 2Fe 17, Er 6Fe 23, ErFe 3, ErFe 2, Er 5Sb 3, αErSb, βErSb, ErSb 2 and ternary compound Er 6FeSb 2 were treated as stoichiometric compounds. The thermodynamic description of the Fe–Sb system was taken from the literature. A self-consistent thermodynamic description of the Er–Fe–Sb system was obtained.

Supplementary measurements of the primary crystalline phases of the Co–Ni–Sb and the Co–Fe–Sb ternary systems

Some primary crystalline phases of the Co–Ni–Sb and the Co–Fe–Sb systems are studied on the basis of the crystalline structure analysis by X-ray diffraction (XRD), the microstructure observation by scanning electron microscopy (SEM), the composition determination by electron probe microanalysis (EPMA) and the phase equilibrium relations of the constituent binary systems. From the experimental measurements of the present work and the phase equilibrium relations of literature reports, the liquidus projections of the Co–Ni–Sb and the Co–Fe–Sb ternary systems are determined. There exist 6 primary crystalline phases in each of the ternary systems, which are γ(A1)–Fcc_A1, β(Co,Ni) 3Sb–D0 3, γ(Co,Ni)Sb–NiAs, ζ(Co,Ni)Sb 2–FeS 2, η(Co,Ni)Sb 3–CoAs 3 and Sb–Rhombo_A7 in the Co–Ni–Sb system and γ(A1)–Fcc_A1, α(A2)–Bcc_A2, γ(Co,Fe)Sb–NiAs, ζ(Co,Fe)Sb 2–FeS 2, η(Co,Fe)Sb 3–CoAs 3 and Sb–Rhombo_A7 in the Co–Fe–Sb system. Two of invariant reactions are proposed, which are the eutectic reaction L → γ(A1) + β(Co,Ni) 3Sb + γ(Co,Ni)Sb in the Co–Ni rich side of the Co–Ni–Sb system and the transition reaction L + γ(A1) → α(A2) + γ(Co,Fe)Sb in the Co–Fe rich side of the Co–Fe–Sb system.

Experimental investigation and thermodynamic calculation of the Zn–Fe–Sb system

The 873 K isothermal section of the Zn–Fe–Sb ternary system was experimentally determined using scanning electron microscopy (SEM) coupled with wave dispersive X-ray spectroscopy (WDS) and X-ray powder diffraction (XRD). A ternary compound FeZnSb was found in this system at 873 K. Experimental results indicate that Sb solubility in δ and Γ phases is less than 1 at.%. At this temperature, the liquid phase is in equilibrium with all phases in the system except α -Fe phase. Based on the experiment results together with available information in the literature, a thermodynamic description for the Zn–Fe–Sb system was developed. The ternary compound FeZnSb was treated as a stoichiometric compound. Good agreement was obtained between the calculation and the experimental results.

The surface tension of liquid Cu–Fe–Sb alloys

The results of study on the influence of temperature and iron and antimony on the surface tension of liquid ternary Cu–Fe–Sb systems are presented. The measurements were carried out with the sessile drop method, in a broad range of the alloy additions concentration (Fe and Sb). It was demonstrated that the surface tension varies as a linear function of temperature and concentration of iron. It was also demonstrated that antimony, in examined alloys, shows the properties characteristic of a surface-active substance, significantly reducing the surface tension value. The changes of the surface tensions as a function of concentration of antimony were described with the Szyszkowski's equation. Composition of surface layer, enriched with an antimony, was determined basing on the model, which used data regarding properties of binary systems. The surface tension values of Cu–Fe–Sb systems was also computed from model and compared with experimental data. A good agreement was obtained.

Phase relationships in the Gd–Fe–Sb system at 773K

Phase relationships in the Gd–Fe–Sb system at 773K

ChemInform Abstract: Phase Relationships in the La—Fe—Sb System at 773 K.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Phase Relationships in the Pr—Fe—Sb System at 773 K.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Phase relationships in the La–Fe–Sb system at 773 K

The isothermal section of the phase diagram of the La–Fe–Sb ternary system at 773 K has been investigated mainly by X-ray powder diffraction with the aid of metallographic analysis and electron probe microanalysis techniques. Two ternary compounds Fe 4LaSb 12 and LaFe 2Sb 2 have been confirmed and LaFe 2Sb 2 is a new ternary compound which was found in this system at 773 K. This isothermal section consists of 12 single-phase regions, 23 two-phase regions and 12 three-phase regions. According to the results of experiment, the homogeneity range of ɛ(FeSb) phase extended from about 44 to 46 at.% Sb, the maximum solid solubility of La in ɛ phase is about less than 1 at.% La at 773 K. The solubilities for the other single-phase regions were not observed. The structure type for LaFe 2Sb 2 is Ga 2S 3-type (sp. gr. Cc (No. 9), a = 0.45518 nm, b = 0.77737 nm, c = 0.84207 nm, β = 128.3946°). FeLaSb 2 and La 3Sb 2 have not been observed at this isothermal section.

Phase relationships in the Pr–Fe–Sb system at 773 K

The isothermal section of the phase diagram of the Pr–Fe–Sb ternary system at 773 K has been investigated mainly by X-ray powder diffraction with the aid of metallographic analysis. Four ternary compounds Fe 4PrSb 12, FePrSb 2, Fe 13Pr 6Sb and FePrSb 3 have been confirmed and a new ternary compound PrFe 2Sb 2 was found in this system at 773 K. The isothermal section consists of 16 single-phase regions, 33 two-phase regions and 19 three-phase regions. The homogeneity range of ɛ (FeSb) phase extended from about 44 at.% Sb to 46 at.% Sb. The solubilities for the other single-phase regions were not observed. The structure type for PrFe 2Sb 2 is Ga 2S 3-type (sp. gr. Cc (no. 9), a = 0.60719 nm, b = 0.60867 nm, c = 1.33051 nm, β=103.1°).

Activities of liquid Fe-As and Fe-Sb alloys saturated with carbon

A solid iron base alloy of the so-called furnace residue is often formed as a by-product in reduction smelting of lead sinter and scraps with high contents of arsenic and antimony. The use of phase separation into a liquid iron-rich alloy and a liquid lead-rich alloy in lead-iron-arsenic and lead-iron-antimony systems saturated with carbon at relatively low temperatures of about 1200°C was proposed in a new process for treating the furnace residue to recover valuable elements into the lead-rich alloy and fix toxic arsenic into the iron-rich alloy. As a fundamental study for the proposed process, the activity coefficients and interaction parameters of the Fe-As and Fe-Sb systems saturated with carbon at 1200°C were derived in this study, based on the determined phase relations in the Fe-Pb-As and Fe-Pb-Sb systems saturated with carbon.

Thermodynamic modeling of the ternary Ce–Fe–Sb system: Assessment of the Ce–Sb and Ce–Fe systems

The two Ce–Sb and Ce–Fe binary systems have been evaluated using the calculation of phase diagram method (CALPHAD). All of the binary compounds are treated as stoichiometric compounds. Solution phases are described with an ordinary substitutional solution model. The model parameters were derived from an optimization procedure using all available experimental data. The reproduction of the thermochemical and phase diagram information is reported in a series of figures and tables.

Phase Relations, Activities and Minor Elements Distribution in Fe–Pb–As and Fe–Pb–Sb Systems Saturated with Carbon at 1473 K

As a fundamental study to develop a new process for treating iron-lead base alloys, speiss, with a considerably high content of arsenic or antimony, which are produced in smelting lead ores or secondary materials of lead under a strongly reductive condition, the phase relations and the minor elements distribution of copper, silver, gold and platinum in the Fe-Pb-As and Fe-Pb-Sb systems saturated with carbon were determined at 1473 K by a quenching method. It was found that a miscibility gap composed of an iron-rich alloy phase with a very small content of lead and a lead-rich alloy phase with very few contents of iron and carbon extended over the wide concentration range. Arsenic was mostly distributed in the iron-rich alloy phase, while antimony almost evenly in both phases. For the distribution of precious metals, it was found that silver was mostly enriched in the lead-rich alloy phase, platinum in the iron-rich alloy phase, while gold and copper almost evenly in both phases. Based on the obtained data of the phase separation and using thermodynamic data for the Pb-As and Pb-Sb binary systems, the activity coefficients of arsenic and antimony in the Fe-As and Fe-Sb systems saturated with carbon at 1473 K were derived and expressed by a formula with the interaction parameters.

Er—Fe—Sb System at 1170 K.

AbstractFor Abstract see ChemInform Abstract in Full Text.

A thermodynamic assessment of the iron — Antimony system

A critical assessment of the Fe-Sb system was carried out by using a computerized technique. Both the liquid and solid solution phases were described by regular solution models. Nonstoichiometric phase, ε-FeSb, was modeled as (Fe)(Fe,Sb), and FeSb 2 was treated as a stoichiometric compound. A set of parameters describing the Gibbs energies of the different phases was optimized by using the existing phase diagram information and thermodynamic properties under one atmosphere. Assessed phase diagram and thermodynamic data are presented and compared with experimental data.