Sb Phase Research Articles

Antimony-bearing schwertmannite transformation to goethite: A driver of antimony mobilization in acid mine drainage

Antimony(V) mobility in acid mine drainage (AMD) is often controlled by sorption and coprecipitation with schwertmannite – a poorly-ordered Fe(III) oxyhydroxysulfate mineral. However, due to its metastable nature, schwertmannite transforms over time to more thermodynamically stable Fe(III) phases, such as goethite. This study examines how transformation of Sb(V)-bearing schwertmannite to goethite impacts Sb(V) mobility, while also assessing the role that Sb(V) may play in stabilizing schwertmannite against such transformation. To address these aims, Sb(V)-free, Sb(V)-sorbed and Sb(V)-coprecipitated schwertmannite were allowed to undergo partial transformation to goethite under acid sulfate conditions. Iron K-edge EXAFS spectroscopy revealed that sorbed and coprecipitated Sb(V) partly stabilized schwertmannite against transformation. The onset of schwertmannite transformation to goethite was found to drive clear mobilization of Sb(V) into solution, regardless of the Sb(V) loading or whether Sb(V) was initially sorbed or coprecipitated with the precursor schwertmannite. This initial phase of Sb(V) mobilization was followed by subsequent solid-phase recapture of the released Sb(V), with Sb K-edge EXAFS spectroscopy revealing that this process involved Sb(V) incorporation into the newly-formed goethite. Our findings show that, although schwertmannite transformation to goethite is partially inhibited by co-existing Sb(V), the initial stage of this transformation process drives significant Sb(V) mobilization in AMD systems.

Aluminum antimony alloy overlayers synthesized using the electrodeposition method: investigation of structural, optical, electrical properties, and DFT calculation

Abstract This paper presents the synthesis of aluminum antimony (Al–Sb) alloy overlayers using an electrodeposition method for application in optoelectronic devices with various applied constant voltages (2, 4, 6, 8, and 10 V) controlled by a DC power supply. The corresponding energy dispersive x-ray spectroscope spectra show that elements including Al, Sb, and Cl were detected in the layers under all conditions of the applied voltage. The structural properties of the formulated compound layers were studied for their structural properties through x-ray diffraction patterns, and all the diffraction peaks exhibited a cubic phase structure. The Al–Sb alloy overlayers were incorporated with nanoparticles and had crystallite sizes ranging from ∼55 to 282 nm. The average transmittance T(λ) values in the visible to near-infrared region were ∼28.36%, 17.64%, 14.07%, 7.83%, and 5.84%, while the average reflectance R(λ) values were ∼3.80%, 1.69%, 1.30%, 0.47%, and 0.21% for applied voltages of 2–10 V, respectively. The energy band gap (E g) existing in the overlayers was determined using Tauc’s plot with the Kubelka–Munk function and it was inferred to be between 1.90 eV and 2.72 eV. The dispersion constants and energies of the prepared samples were also investigated. The 2 V applied voltage-treated Al–Sb alloy overlayers showed the highest average χ(1), χ ( 3 ) , and n 2 values of 0.088, 1.680 × 10−14 esu., and 4.082 × 10−13 esu., respectively. In addition, the resistance at various absolute temperatures was also recorded for the activation energy (E AC) values of the Al–Sb alloy overlayers with applied voltages of 2–10 V. Finally, ab initio calculations based on density functional theory were performed to support the experimental report of the Al–Sb systems. It was found that the calculated lattice constants are in good agreement with the experimental results, and a wider photoabsorption range performance for Al–Sb phase I in the axis of energy seems to be suitable for application as an optical device.

Morphologically and Compositionally Controlled Cs2SbBr6 by Bi and Ag Substitution

AbstractMorphology‐controlled Cs2SbBr6 crystals are synthesized by Bi‐ and Ag‐substitution of the precursor solution. X‐ray diffraction (XRD) together with Raman spectroscopy confirms the lattice tilting and symmetry changes with the dominant appearance of higher index facets by Bi substitution. Ag substitution does not induce crystal symmetry changes in the Cs2BBr6 (B = Sb or Bi) phase, but results in highly defective structures hindering the formation of a smooth surface during the crystal growth. Successful substitution of Bi and limited substitution of Ag into Cs2SbBr6 is also confirmed by energy dispersive X‐ray spectroscopy (EDX). This research provides design principles and practical examples of how to control the morphology of Cs2SbBr6 crystals with structural defects and multiphase formation.

Multilevel phase transition behavior of In2Se3-doped with Sb materials based on flexible polyimide substrate

The In2Se3-doped Sb phase change material was deposited onto a polyimide substrate using magnetron sputtering technique. A comprehensive investigation was conducted on the thermal stability, bending resistance, crystal structure, and electrical properties of this material. The findings revealed its remarkable thermal stability, data retention, and bending resilience, particularly in the In0.05Se0.19Sb0.76 film, which exhibited minimal resistance drift. The aging test confirmed the stability of the electronic structure in In2Se3-doped Sb, accompanied by reduced structural relaxation. Notably, no new crystalline phase emerged in In0.05Se0.19Sb0.76 film, but stronger In-Sb bonds were formed. Raman spectroscopy and bending tests further indicated that deformation had minimal impact on the film’s structure and surface. Utilizing the In0.05Se0.19Sb0.76 material and polyimide substrate, a flexible phase change memory device demonstrated reliable SET/RESET operations even after bending, offering three stable resistance states for multilevel storage. This enhanced the storage density, making In2Se3-doped Sb material a promising flexible phase change material with excellent performance and vast potential for applications in phase change storage, such as electronic fabrics and flexible smart wearable electronics.

The Effect of Sputtering Sequence Engineering in Superlattice-like Sb-Rich-Based Phase Change Materials.

This paper presents a comprehensive investigation into the thermal stability of superlattice-like (SLL) thin films fabricated by varying the sputtering sequences of the SLL [Ge8Sb92(25nm)/GeTe(25nm)]1 and SLL [GeTe(25nm)/Ge8Sb92(25nm)]1 configurations. Our results reveal significantly enhanced ten-year data retention (Tten) for both thin films measured at 124.3 °C and 151.9 °C, respectively. These values surpass the Tten of Ge2Sb2Te5 (85 °C), clearly demonstrating the superior thermal stability of the studied SLL configurations. Interestingly, we also observe a distinct difference in the thermal stability between the two SLL configurations. The superior thermal stability of SLL [GeTe(25nm)/Ge8Sb92(25nm)]1 is attributed to the diffusion of the Sb precipitated phase from Ge8Sb92 to GeTe. This diffusion process effectively reduces the impact of the Sb phase on the thermal stability of the thin film. In contrast, in the case of SLL [Ge8Sb92(25nm)/GeTe(25nm)]1, the presence of the Sb precipitated phase in Ge8Sb92 facilitates the crystallization of GeTe, leading to reduced thermal stability. These findings underscore the significant influence of the sputtering sequence on the atomic behavior and thermal properties of superlattice-like phase change materials. Such insights provide a robust foundation for the design and exploration of novel phase change materials with improved thermal performance.

Development of Sb phase change thin films with high thermal stability and low resistance drift by alloying with Se

A single Sb phase demonstrates potential for use in phase change memory devices. However, the rapid crystallization of Sb at room temperature imposes limitations on its practical application. To overcome this issue, Sb is alloyed with Se using a reactive co-sputtering deposition technique, employing both Sb and Sb2Se3 sputter targets. This process results in the formation of Sb-rich Se thin films with varying compositions. Compared to pure Sb, the Sb-rich Se thin films exhibit enhanced thermal stability due to the formation of Sb–Se bonds and reduced resistance drift. In particular, the Sb86.6Se13.4 thin film demonstrates an exceptionally low resistance drift coefficient (0.004), a high crystallization temperature (Tc = 195 °C), a high 10-year data retention temperature (116.3 °C), and a large crystallization activation energy (3.29 eV). Microstructural analysis of the Sb86.6Se13.4 reveals the formation of a trigonal Sb phase with (012) texture at 250 °C, while Sb18Se and Sb2Se3 phases form at 300 °C. Conversely, the Sb98.3Se1.7 thin film shows the formation of the single Sb phase with (001) texture, a Tc of 145 °C, and a low resistance drift coefficient (0.011). Overall, this study demonstrates that the alloying strategy is a viable approach for enhancing thermal stability and reducing resistance drift in Sb-based phase-change materials.

Structural characteristics, mechanical properties, electronic behavior, and lattice thermal conductivities for novel LaX phases (X = P, As, Sb)

Rare-earth-metal monopnictides have rich high-pressure structures, magnetism, and topological properties, but there is still relatively little research related to them, especially in recent years. We here predict a new group of LaX (X = P, As, Sb) phases (HR-type) by means of the particle swarm optimization method. Their stabilities can be verified by dynamic, thermodynamic, and mechanical calculations. By utilizing the density functional and semiclassical Boltzmann transport theory, we investigate their mechanic, electronic, and thermal transport properties. These HR-type LaX are rather soft with lower than 6 GPa of Vickers hardness, and exhibit the obvious mechanical anisotropy. These HR-type LaX also exhibit amazing topological properties, owning a mostly flat surface band between two bulk Dirac cones. Based on the calculations of gaps in energy dispersion planes and Z2 invariants, we prove that these HR-type LaX should be the nodal-line semimetals. We compute their lattice thermal conductivities, and find that HR-type LaAs own the largest lattice thermal conductivity of 6.34 (22.34) W/mK along x (y) direction at 300 K. This mean free path of the pertinent heat-carrying phonons in the HR-type LaX are also predicted. Our research might offer new perspectives on the various allotropes of rare-earth-metal monopnictides.

Study on the modulation of sb phase change thin films and device properties by MoTe2 heterojunction layer

Study on the modulation of sb phase change thin films and device properties by MoTe2 heterojunction layer

Theoretical Prediction and Experimental Synthesis of Zr3AC2 (A = Cd, Sb) Phases.

MAX phases have great research value and application prospects, but it is challenging to synthesize the MAX phases containing Cd and Sb for the time being. In this paper, we confirmed the existence of the 312 MAX phases of Zr3CdC2 and Zr3SbC2, both from theoretical calculations and experimental synthesis. The Zr3AC2 (A = Cd, Sb) phase was predicted by the first-principles calculations, and the two MAX phases were confirmed to meet the requests of thermal, thermodynamic, and mechanical stabilities using formation energy, phonon dispersion, and the Born-Huang criteria. Their theoretical mechanical properties were also systematically investigated. It was found that the elastic moduli of Zr3CdC2 and Zr3SbC2 were 162.8 GPa and 164.3 GPa, respectively. Then, differences in the mechanical properties of Zr3AC2 (A = Cd, In, Sn, and Sb) were explained using bond layouts and charge transfers. The low theoretical Vickers hardness of the Zr3CdC2 (5.4 GPa) and Zr3SbC2 (4.3 GPa) phases exhibited excellent machinability. Subsequently, through spark plasma sintering, composites containing Zr3CdC2 and Zr3SbC2 phases were successfully synthesized at the temperatures of 850 °C and 1300 °C, respectively. The optimal molar ratio of Zr:Cd/Sb:C was determined as 3:1.5:1.5. SEM and the EDS results analysis confirmed the typical layered microstructure of Zr3CdC2 and Zr3SbC2 grains.

THERMODYNAMIC STUDY OF THE CdSb COMPOUND BY THE ELECTROMOTIVE FORCE MEASUREMENTS METHOD

Thermodynamic properties of CdSb binary compound were determined using an electromotive force measurement (e.m.f.) method with a liquid electrolyte in the ~300-450K temperatures interval. Equilibrium alloys from the CdSb+Sb phase region of the Cd-Sb system was analyzed by means of the e.m.f. measurements. Phase compositions of all samples were controlled using powder X-rays diffraction method. The partial molar functions of cadmium in alloys, the standard thermodynamic functions of formation, as well as the standard entropy of the CdSb compound were calculated. A comparative analysis of obtained results with literature data was performed.

Ba5Sb8: The Highest Homologue of the Family of Binary Semiconducting Barium Antimonides BanSb2n−2 (n ≥ 2)

A novel binary compound within the Ba–Sb phase diagram, Ba5Sb8, was synthesized by combining elements with an excess of Sb in an alumina crucible. Structural elucidation was performed using single-crystal X-ray diffraction. This compound crystallizes in the orthorhombic space group Fdd2 with unit cell parameters of a = 15.6568(13) Å, b = 35.240(3) Å, c = 6.8189(6) Å, adopting its own structure type. The most distinctive features of the structure are the eight-membered [Sb8]10− polyanionic fragments which have no known precedents among antimonides. They are separated by five Ba2+ cations, which afford the charge balance and enable adherence to the Zintl–Klemm formalism. Ba5Sb8 is the highest known member of the homologous series within the family of barium antimonides BanSb2n−2 (n ≥ 2), all of which boast anionic substructures with oligomeric moieties of pnictogen atoms with varied lengths and topologies. Electronic structure calculations indicate an indirect narrow bandgap of ca. 0.45 eV, which corroborates the valence-precise chemical bonding in Ba5Sb8.

Cu-Cu joint with Sn-58Bi/Porous Cu/Sn-58Bi transient liquid phase bonding under formic acid atmosphere

PurposeThis paper aims to examine the effects of bonding temperature, bonding time, bonding pressure and the presence of a Pt catalyst on the bonding strength of Cu/SB/P-Cu/SB/Cu joints by transient liquid phase bonding (TLPB).Design/methodology/approachTLPB is promising to assemble die-attaching packaging for power devices. In this study, porous Cu (P-Cu) foil with a distinctive porous structure and Sn-58Bi solder (SB) serve as the bonding materials for TLPB under a formic acid atmosphere (FA). The high surface area of P-Cu enables efficient diffusion of the liquid phase of SB, stimulating the wetting, spreading and formation of intermetallic compounds (IMCs).FindingsThe higher bonding temperature decreased strength due to the coarsening of IMCs. The longer bonding time reduced the bonding strength owing to the coarsened Bi and thickened IMC. Applying optimal bonding pressure improved bonding strength, whereas excessive pressure caused damage. The presence of a Pt catalyst enhanced bonding efficiency and strength by facilitating reduction–oxidation reactions and oxide film removal.Originality/valueOverall, this study demonstrates the feasibility of low-temperature TLPB for Cu/SB/P-Cu/SB/Cu joints and provides insights into optimizing bonding strength for the interconnecting materials in the applications of power devices.

Antimony contamination sources and alteration pathways of Sb mineral phases in an abandoned mining area: The role of secondary mopungite [NaSb(OH)6

Antimony pollution caused by mining activities is a current environmental concern. This study investigates the processes involved in the Sb release and mobility in the abandoned Sb mine of Su Suergiu (SE Sardinia, Italy). Analyses of outcropping rocks, mine wastes and smelting slags by means of X-Ray Powder Diffraction, Scanning Electron Microscopy - Energy Dispersive Spectroscopy and Electron Microprobe – Wavelength Dispersive Spectroscopy provided mineralogical and compositional data which contributed to the discussion about the oxidation pathways of Sb phases. The main Sb sources are metallic Sb and Sb2O3 (valentinite/senarmontite), dumped in the smelting slag heaps as residues of metallurgical processes, and primary stibnite (Sb2S3) found in natural outcrops and mine wastes. These minerals, subjected to weathering processes, release Sb in solution where it is oxidized and remains as dissolved Sb(OH)6−. Carbonates and Na phases, like hydrate NaAl-silicate derived from metallurgical processes, influence the geochemical equilibria of the smelting slag heaps, where the precipitation of the rare mopungite, Na[Sb(OH)6], has been observed. At Su Suergiu, mopungite originates from a dissolution-precipitation process as the last forming mineral of the oxidation pathways, limiting the Sb mobility by bonding the Sb(OH)6− in solution. Among the detected Sb secondary phases (e.g., Sb-oxides, FeSb-oxides, etc.), mopungite is the prevalent Sb binder although it acts as a temporary sink because its stability is influenced by the hydrological regime, its solubility, and the water physicochemical parameters. Secondary Sb-bearing minerals can control the dispersion of Sb in contaminated area. At Su Suergiu the role of Fe-bearing compounds on Sb mobility is subordinate to that of mopungite due to the specific geochemical conditions related to the metallurgical activities. The relevance of this study arises from the known toxicity of Sb and from its worldwide diffuse mining, that results in the widespread occurrence of Na–Sb-rich residues produced by Sb smelting plants.

Improved performance in Mg3Sb2/Sb hybrid films for thermoelectric generation

Mg3Sb2-based bulk materials show great potential in both waste-heat recovery and cooling applications because of their excellent thermoelectric performance. But for the Mg3Sb2-based thermoelectric films, few efforts are devoted to it. Here, the p-type Mg3Sb2-based thermoelectric films have been successfully fabricated using the radio frequency magnetic sputtering method, which are composed of Mg3Sb2 and Sb phases. Interestingly, the ratio of Mg3Sb2 and Sb phases can be regulated by adjusting deposition temperature, where thermoelectric performance can be optimized, obtaining high power factor of 43.21 μV m−1 K−2 at 195 ℃. Furthermore, both Seebeck coefficient and electrical conductivity of Mg3Sb2 films are rarely decreased even after one month of exposure to air, demonstrating good stability. In order to further evaluate practicability, the output powers of Mg3Sb2/Sb films are measured at different temperature differences (ΔT), where an output voltage of ∼0.9 mV is achieved at ΔT of 31 ℃. In particular, the output power is basically consistent in the periodic cycle measurement, further implying a good stability. This work can provide a new thinking, enlightening more researchers to focus on the Mg3Sb2-based low-dimensional materials, and promoting its applications.

Arsenic and antimony geochemistry of historical roaster waste from the Giant Mine, Yellowknife, Canada

Historical mining and mineral processing at the former Giant Mine (Yellowknife, NT, Canada) created an enduring legacy of arsenic (As) and antimony (Sb) contamination. Approximately 237,000 tonnes of arsenic trioxide roaster waste (ATRW) generated between 1948 and 1999 remains stored on-site in underground chambers. We studied the chemical forms and phase associations of As and Sb to improve understanding of ATRW environmental behavior. Although arsenolite [As2O3] is the principal As and Sb host, we also observed minor associations of As with Fe oxides. Arsenic K-edge X-ray absorption spectroscopy (XAS) revealed As(III) dominated ATRW, with some As(V) and As(−I) also present. Arsenic coordination and bonding is consistent with arsenolite, while scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) showed minor As association with Fe oxides and arsenopyrite [FeAsS]. Antimony K-edge XAS revealed variable proportions of Sb(III) and Sb(V), with Sb−O, Sb−Sb and Sb−As bonding consistent with stibioclaudetite [AsSbO3] or Sb-substituted arsenolite. Electron microprobe analysis (EMPA) results showed variable but quantitative Sb substitution for As in arsenolite grains, possibly influencing ATRW solubility and reactivity under environmental conditions. Overall, our results reveal complex As and Sb phase associations with important implications for ongoing remediation efforts and long-term environmental fate of ATRW solids.

In Situ Atomic-Scale Deciphering of Multiple Dynamic Phase Transformations and Reversible Sodium Storage in Ternary Metal Sulfide Anode.

Ternary metal sulfides (TMSs), endowed with the synergistic effect of their respective binary counterparts, hold great promise as anode candidates for boosting sodium storage performance. Their fundamental sodium storage mechanisms associated with dynamic structural evolution and reaction kinetics, however, have not been fully comprehended. To enhance the electrochemical performance of TMS anodes in sodium-ion batteries (SIBs), it is of critical importance to gain a better mechanistic understanding of their dynamic electrochemical processes during live (de)sodiation cycling. Herein, taking BiSbS3 anode as a representative paradigm, its real-time sodium storage mechanisms down to the atomic scale during the (de)sodiation cycling are systematically elucidated through in situ transmission electron microscopy. Previously unexplored multiple phase transformations involving intercalation, two-step conversion, and two-step alloying reactions are explicitly revealed during sodiation, in which newly formed Na2BiSbS4 and Na2BiSb are respectively identified as intermediate phases of the conversion and alloying reactions. Impressively, the final sodiation products of Na6BiSb and Na2S can recover to the original BiSbS3 phase upon desodiation, and afterward, a reversible phase transformation can be established between BiSbS3 and Na6BiSb, where the BiSb as an individual phase (rather than respective Bi and Sb phases) participates in reactions. These findings are further verified by operando X-ray diffraction, density functional theory calculations, and electrochemical tests. Our work provides valuable insights into the mechanistic understanding of sodium storage mechanisms in TMS anodes and important implications for their performance optimization toward high-performance SIBs.

Thermoelectric properties and microstructure of nanocomposite Sb-GeO2 and Sb–TiO2 thin films

This work reports on fabrication and thermoelectric properties of Sb-GeO2 and Sb–TiO2 nanocomposite thin films. The formation of nanocomposite structure includes the precipitation of Sb phase and the amorphous GeO2 or TiO2 phase. In the Sb-GeO2 nanocomposite, the formation of large rhombohedral Sb grains is observed, where monoclinic Sb are formed as intermediate phase. This contributes remarkably to the elevation of conductivity, while results in the reduction of Seebeck coefficient and power factor. Contrary, the effective inhibition of Sb crystallization caused by TiO2 leads to the smaller monoclinic and rhombohedral Sb grains with homogeneous distribution in annealed Sb–TiO2 thin film. The existence of monoclinic Sb facilitates to acquire excellent thermoelectric properties. Tiny grains within the films introduce more grain boundaries, making it possible to scatter and filter low energy carriers. This leads to high conductivity, remarkable rise of the Seebeck coefficient, and excellent power factor of 765.5 μW/mK2 at 650 K. The results demonstrate that the Sb–TiO2 nanocomposite materials with high power factor can be a candidate for thermoelectric devices.

Induced nonstoichiometric effects of Sb in p-type skutterudite thermoelectrics

Sublimation of antimony (Sb) during synthetic processes can be fatal to the thermoelectric (TE) properties of MT4Sb12 (M: filler atoms; T = Fe, Co, Ni)-based skutterudite (SKD). In this study, the nonstoichiometric effects of Sb on the phase structure formation and, thereby, on the TE properties of p-type SKD with Nd0.9Fe3.5Co0.5Sb12+x compounds were systematically investigated. Research is carried out with x values varying from −0.8 to 1.0, and samples are prepared by combining induction melting and melt-spinning, followed by a spark plasma sintering (SPS) process. The analysis showed that the Sb-deficiency formed NdSb and FeSb2 secondary phases along with the SKD main phase, while the Sb-excess effectively suppressed the FeSb2 phase formation and a small amount of the Sb phase appeared at a high Sb-excess level. The appearance of the secondary phases induced by Sb nonstoichiometry directly affected the change in the filling fraction of Nd in the SKD crystal structure, which led to the carrier concentration change. Our results demonstrate that the TE performance of MT4Sb12-based compounds can be significantly changed by the Sb nonstoichiometry, which should be profoundly considered along with other strategies to improve the TE efficiency of Sb-based SKD materials.

Enhancing the Thermal Stability and Reducing the Resistance Drift of Sb Phase Change Films by Adding In2Se3 Interlayers

In this paper, pure Sb and composite multilayer In2Se3/Sb thin films were prepared on a SiO2/Si substrate. The effects of the addition of In2Se3 interlayers on the physical and electrical properties of phase change thin films were investigated. Compared with pure Sb film, the composite multilayer In2Se3/Sb film had a higher crystallization temperature (~145 °C), larger crystallization activation energy (~2.48 eV), less resistance drift (~0.0238) and better thermal stability. The results of X-ray photoelectron spectroscopy indicated that the In-Sb bond was formed in the multilayer In2Se3/Sb film. The near infrared spectrophotometer showed that the band gap changed at different annealing temperatures. Changing the annealing temperature of the film allowed for the phase structure of the film to be studied by using X-ray diffractometer. The surface morphology and electrostatic potential at different annealing temperatures were using atomic force microscope. It was found that the flat film had a smoother surface. Phase-change memory devices based on [In2Se3(4 nm)/Sb(6 nm)]8 film reduced power consumption by approximately 74% compared to pure Sb film. In conclusion, the In2Se3 interlayers effectively inhibited the resistance drift of the phase change thin film and enhanced its thermal stability.

Phase diagrams of the thermoelectric Bi–Sb–Se system

Bi–Sb–Se is an important thermoelectric material system. However, a phase diagram of the entire compositional range is not available in the literature. This study determines the Bi–Sb–Se liquidus projection and its phase equilibria isothermal section at 400 °C. Ternary Bi–Sb–Se alloys are prepared. Their primary solidification phases and invariant reactions are determined. There are seven primary solidification phases, (Se), Bi2Se3, Sb2Se3, (Bi,Sb), (Bi2)m(Bi2Se3)n, Bi3Sb5Se2 and Bi3Sb12Se5. Both Bi3Sb5Se2 and Bi3Sb12Se5 are newly found ternary compounds. In the Bi–Sb–Se isothermal section at 400 °C, there are eight three-phase regions. Besides these two ternary compounds, the other single phases are, Sb2Se3, Bi2Se3, (Bi2)m(Bi2Se3)n, Liquid (Bi,Sb), Liquid (Se), and (Bi,Sb) phases. It has been found the solubilities of Sb in the (Bi2)m(Bi2Se3)n and Bi2Se3 compounds are significant.