Sb Solid Solution Research Articles

Effects of Sb on the properties and interfacial evolution of SAC305-2Bi-xSb/Cu solder joints

This study investigated the influence of Sb addition on the microstructure, thermal behavior, mechanical properties, and interfacial evolution of SAC305-2Bi-xSb/Cu solder joints. Compared with the SAC305-2Bi alloy, the melting temperature and pasty range slightly increased with the increasing of Sb content from 0.2 to 2.0 wt.%, while the undercooling temperature decreased. The research revealed that with the addition of Sb element, the grain size of β-Sn is refined. When the content of Sb is 0.5 wt.%, the grain size of β-Sn reached minimum (19.91 μm). Compared to the SAC305-2Bi alloy, the ultimate tensile strength of SAC305-2Bi–2Sb alloy is increased by 30.10%, contributed to the Sb solid solution strengthening effect and the refinement of β-Sn. With the addition of Sb, the thickness and growth rate of the interface is reduced gradually. The uniform solution of Sb and Sn can significantly inhibit the diffusion rate of Cu atoms and Sn atoms at the interface. The SAC305-2Bi-xSb alloy system has low melting temperature, superior mechanical properties, and reliable solder joints for service. Therefore, it is a potentially reliable lead-free solder for high-stability connections in automotive electronics, communications electronics, and medical devices.

Investigating the Role of Vacancies on the Thermoelectric Properties of EuCuSb-Eu2 ZnSb2 Alloys.

AMX compounds with the ZrBeSi structure tolerate a vacancy concentration of up to 50 % on the M-site in the planar MX-layers. Here, we investigate the impact of vacancies on the thermal and electronic properties across the full EuCu1-x Zn0.5x Sb solid solution. The transition from a fully-occupied honeycomb layer (EuCuSb) to one with a quarter of the atoms missing (EuZn0.5 Sb) leads to non-linear bond expansion in the honeycomb layer, increasing atomic displacement parameters on the M and Sb-sites, and significant lattice softening. This, combined with a rapid increase in point defect scattering, causes the lattice thermal conductivity to decrease from 3 to 0.5 W mK-1 at 300 K. The effect of vacancies on the electronic properties is more nuanced; we see a small increase in effective mass, large increase in band gap, and decrease in carrier concentration. Ultimately, the maximum zT increases from 0.09 to 0.7 as we go from EuCuSb to EuZn0.5 Sb.

Bismuth−Antimony Alloy Embedded in Carbon Matrix for Ultra-Stable Sodium Storage

Alloy-type anodes are the most promising candidates for sodium-ion batteries (SIBs) due to their impressive Na storage capacity and suitable voltage platform. However, the implementation of alloy-type anodes is significantly hindered by their huge volume expansion during the alloying/dealloying processes, which leads to their pulverization and detachment from current collectors for active materials and the unsatisfactory cycling performance. In this work, bimetallic Bi-Sb solid solutions in a porous carbon matrix are synthesized by a pyrolysis method as anode material for SIBs. Adjustable alloy composition, the introduction of porous carbon matrix, and nanosized bimetallic particles effectively suppress the volume change during cycling and accelerate the electrons/ions transport kinetics. The optimized Bi1Sb1@C electrode exhibits an excellent electrochemical performance with an ultralong cycle life (167.2 mAh g-1 at 1 A g-1 over 8000 cycles). In situ X-ray diffraction investigation is conducted to reveal the reversible and synchronous sodium storage pathway of the Bi1Sb1@C electrode: (Bi,Sb) Na(Bi,Sb) Na3(Bi,Sb). Furthermore, online electrochemical mass spectrometry unveils the evolution of gas products of the Bi1Sb1@C electrode during the cell operation.

Entropy engineering: A simple route to both p- and n-type thermoelectrics from the same parent material

Ternary half-Heusler (HH) semiconductors have been identified as excellent high-temperature thermoelectric (TE) materials, but the high thermal conductivity restricts the development and application. In this work, we report the design of the HH alloy Ti(Fe/Co/Ni)Sb with both p-type and n-type conductions from the same parent compound TiCoSb by entropy engineering. High-throughput (HTP) experiments have been first conducted to verify the formation of Ti(Fe1/3+xCo1/3Ni1/3-x)Sb solid solution and screen the range of compositions with the best p-type and n-type thermoelectric properties by regulating the Fe/Ni ratio. The random mixing of Fe/Co/Ni on the 4c site of the HH lattice induces a large lattice distortion, leading to a significantly reduced lattice thermal conductivity. Adjusting the sample composition (Fe/Ni ratio) changes the carrier concentration, carrier type and electronic band structure simultaneously, contributing to improved TE power factors for both p- and n-type materials. As a result, a peak TE figure of merit zT of up to ∼0.56 for p-type and ∼0.49 for n-type are achieved. Our experimental results demonstrate that entropy engineering is a promising strategy to extend the composition range and tune the TE properties for HH materials, which might be a generally applicable route to improve the thermoelectric performance of other TE materials.

Influence of Second Phase Particles on Thermal Conductivity of Bi Alloys

High-Bi alloys are being explored to understand their potential as replacement for high-Pb alloys in high-temperature die-attach applications. Thermal conductivity of these alloys is an important consideration for die-attach applications, where heat dissipation is necessary for reliable operation of the devices. Pure Bi has a thermal conductivity of about 8 W/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{m}\cdot \text{K}$ </tex-math></inline-formula> , which is the lowest among metals. The addition of the alloying elements to Bi had been explored to tailor its thermal, mechanical, and other physical properties. In this study, the role of Cu and Sb on the effective thermal conductivity of the resultant alloys was investigated. The thermal conductivities of these alloys in the bulk form and the three-layer die-attach form were measured using a flash diffusivity technique. Test specimens were developed to replicate a die-attach assembly between the Ni-metallized Si die and Cu substrate using the Bi– <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula> Sb–10Cu alloy (where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$x =10$ </tex-math></inline-formula> –20 wt%). The three-layered structure was modeled with the unknown diffusivity of an intermediate layer of the Bi alloy. The alloy microstructure comprises a composite of Bi–Sb solid solution filled with Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Sb intermetallic particles. The presence of these intermetallic phases is responsible for an effective increase in thermal conductivity of this alloy. With the optimized microstructure developed, the resultant thermal conductivity was obtained at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 24$ </tex-math></inline-formula> W/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{m}\cdot \text{K}$ </tex-math></inline-formula> , which is a threefold increase compared to pure Bi.

Energetic and electrokinetic characteristics of semiconducting solid solution TiСo1-xMnxSb

The samples of TiСo 1- x Mn x Sb solid solution ( x = 0.01, 0.02.03, 0.04, 0.05 0.07 and 0.10) were synthesized in an electric arc furnace. Homogenizing annealing was carried out at 1070 K for 720 hours. X-ray diffraction analysis was performed using the diffractometer DRON-2.0m (Fe K α -radiation). The temperature and concentration dependences of the electrical resistivity and thermopower relative to copper of the samples were measured in the temperature range 80–400 K. According to X-ray diffraction analysis, the synthesized samples belong to the MgAgAs structure type (space group F 3 m ). Previous researches of the half-Heusler phase TiCoSb and the solid solutions based on it TiCo 1- x Ni x Sb, TiCo 1- x Cu x Sb, Ti 1- x V x CoSb, Ti 1- x Mo x CoSb, Ti 1- x Sc x CoSb, allowed to establish both the defectivity in the structure of the TiCoSb compound and the mechanisms of the introduction of impurity atoms into its structure. It was found that in the structure of the compound TiCoSb there are simultaneously ~ 1% vacancies in the position 4a of Ti atoms and ~ 1% of additional Co * atoms in the tetrahedral voids of the structure, which can be described by the formula (Ті 0.99 Va с 0.01 )Co(Co * 0.01 )Sb. In this case, vacancies in the position of Ti atoms generate structural defects of acceptor nature, and additional Co* atoms in the tetrahedral voids of the structure generate defects of donor nature. The calculation of the density of electronic states of TiСo 1- x Mn x Sb solid solution, for an ordered variant of the structure in which the Co atoms are replaced by Mn atoms in 4 c position, showed that the Fermi level is in the band gap and shifts toward the valence band as the concentration of Mn increases. Such behavior of the Fermi level would have to lead to maximum values of resistivity and change the sign of the thermopower coefficient of TiСo 1- x Mn x Sb from negative to positive, and the intersection of the Fermi level and the valence band should change the conduction from semiconducting to metallic type. The obtained experimental results of the electrokinetic characteristics for TiСo 1- x Mn x Sb indicate that more complicated structural changes occur in the crystal than the linear substitution of Co atoms by Mn ones. At low concentrations of Mn atoms ( x = 0.01 and 0.02), the temperature dependence of resistivity has an activating character, at x = 0.03 and 0.04 it has metallic type and at concentrations x = 0.07 and 0.10 again activations take place. In turn, negative values of the thermopower coefficient of TiСo 1- x Mn x Sb for all investigated samples indicate that electrons are the majority charge carriers. Thus, based on the study of electronic structure, electrokinetic and energetic characteristics of TiСo 1- x Mn x Sb, it was established that both structural defects of acceptor and donor nature (the effective charge of which is opposite) are generated, the concentration of which increases with increasing Mn atoms. Keywords: electrical conductivity, thermopower coefficient, Fermi level, structural defect.

Nanostructured SiGe:Sb solid solutions with improved thermoelectric figure of merit

Nanostructured SiGe:Sb solid solutions with improved thermoelectric figure of merit

Cryogenic Thermoelectric Cooler for Operating Temperatures below 90 K

The possibility of fabricating thermoelectric coolers for operating temperatures below 90 K is considered. It is impossible to use the standard thermoelectric-cell scheme consisting of two semiconductor legs of n-type and p-type conductivity connected into an in-series electrical circuit for these temperatures. There is only one effective n-type thermoelectric material based on Bi–Sb solid solutions for the region of cryogenic temperatures. For this case, thermoelectric cells with a thermoelectric n-type leg and passive leg based on a high-temperature superconductor (HTSC) are investigated. The design of a thermoelectric cooler (module) consisting of thermoelectric n-type legs (extruded Bi0.91Sb0.09 crystals) and passive HTSC-based legs (YBa2Cu3O7 –x) is proposed. A magnetic field is used to increase the thermoelectric figure of merit ZT of the module. The maximal temperature drop between the hot and cold sides ΔT > 13.5 K and maximal cooling capacity Qc > 0.36 W are attained for the cryogenic module at a hot side temperature of Th = 80 K, current consumption of I = 6.4 A, and voltage of U = 0.10 V.

Effect of Cu, Ag on the microstructure and IMC evolution of Sn5Sb–CuAgNi/Cu solder joints

In this paper, three new type Sn5Sb-based solders were used to the study. The three sets of solders are Sn–5Sb–0.5Cu–0.1Ni–0.5Ag, Sn–5Sb–0.5Cu–0.1Ni–0.1Ag and Sn–5Sb–1Cu–0.1Ni–0.1Ag. Experimental results indicated that with the increase of Cu and Ag, the solidus temperature reduced due to the increase of the eutectic phase of low melting point Ag3Sn+β-Sn and Cu6Sn5+β-Sn in the solder. The adding elements of Cu, Ni, Ag can improve the wettability of Sn5Sb while excessive Cu, Ag content inhibit the wettability. The Similar microstructures exist in the three groups of solders, which consist of β-Sn–Sb solid solutions, (Cu1−xNix)6Sn5, Ag3Sn and a small amout of β-Sn. The interfacial intermetallic compound (IMC) is composed of (Cu1−xNix)6Sn5. The lower Cu content suppresses the IMC growth by increasing the dissolution of interfacial IMCs into bulk solder but it also increase the IMC growth by elevating the diffusion speed. The thickness of the IMC layer of Sn–5Sb–0.5Cu–0.1Ni–0.1Ag/Cu grow faster than that of Sn–5Sb–1Cu–0.1Ni–0.1Ag/Cu, Which illustrates the Cu atoms affect the IMC mainly through inhibiting the reaction diffusion. The addition of Ag in the solder significantly suppressed the IMC layer in Sn–5Sb–0.5Cu–0.1Ni–0.5Ag/Cu, Which is attributes to the concentration of Ag3Sn near the IMC layer. The increase of Cu, Ag content in the solder will increase the ductility of the solder. The toughness decrease when the liquid keeping time over 30 s and the shear strength decrease correspondingly. The fracture mechanism changed from ductile fracture to tough and brittle hybrid fracture when the liquid keeping time from 10 s to 90 s.

Structural Destruction of As–Sb Solid Solution through a Selective Oxidation Process in the Presence of CaO and Its Effect on As Removal from the As–Sb Dust

As–Sb dust from metallurgical processes causes serious environmental issues due to the presence of the toxic element As. In this study, a facile method for removing As through the destruction of the As–Sb solid solution structure from the dust using CaO under an oxidizing atmosphere was processed. The effects of the variables, including the amount of CaO added, roasting temperature and time, and oxygen partial pressure, on the volatilization of As and Sb were investigated. Under an oxidizing atmosphere in the presence of CaO, the formation of the vitreous material (As–Sb–O) was hindered through the transformation of Sb2O3 and (As, Sb)2O3 in the untreated dust into Sb2O4, Sb2O5, Sb6O13, and Ca2Sb2O7, and the volatilization of arsenic was promoted, as a result. The volatilization attained for As was 91.53% whereas that for Sb was only 4.30% under the following optimum conditions: 5 mass % CaO, a roasting temperature of 550 °C, an O2 partial pressure of 21 vol % (air), and a roasting time of 80 min.

Results of the Experiments on the Crystallization of a Ge–Si–Sb Solid Solution under the Conditions of Microgravity on the Soyuz–Apollo Spacecraft

Objective factors that allow the experiment on growing crystals of a Ge–Si–Sb solid solution on the Soyuz–Apollo spacecraft to take a special place among many experiments on growing single crystals aboard spacecrafts are analyzed. In the study of crystals grown on board a spacecraft, anomalous and unexpectedly high segregation of the solid solution components in the direction transverse to the direction of crystallization is found. An analysis of the obtained results allowed us, for the first time, to establish a causal relationship between anomalous segregation and microgravity features on board a spacecraft. Determining the physical nature of anomalous segregation have affected the direction of further research and give rise to an in-depth study of specific features of the new technological environment, the rapid development of numerical methods for studying heat and mass transfer processes in melts, and the expanding of the range of studied crystals and methods for studying them. A great contribution to the development of this area was made by Professor V.S. Zemskov.

Результаты экспериментов по кристаллизации твердого раствора Ge-Si-Sb на космическом комплексе "Союз--Аполлон" в условиях микрогравитации

AbstractObjective factors that allow the experiment on growing crystals of a Ge–Si–Sb solid solution on the Soyuz–Apollo spacecraft to take a special place among many experiments on growing single crystals aboard spacecrafts are analyzed. In the study of crystals grown on board a spacecraft, anomalous and unexpectedly high segregation of the solid solution components in the direction transverse to the direction of crystallization is found. An analysis of the obtained results allowed us, for the first time, to establish a causal relationship between anomalous segregation and microgravity features on board a spacecraft. Determining the physical nature of anomalous segregation have affected the direction of further research and give rise to an in-depth study of specific features of the new technological environment, the rapid development of numerical methods for studying heat and mass transfer processes in melts, and the expanding of the range of studied crystals and methods for studying them. A great contribution to the development of this area was made by Professor V.S. Zemskov.

Thermoelectric performance of In0.8+yGa0.2Sb (0 ≤ y ≤ 0.06) ternary solid solutions with In excess

N-type In0.8+yGa0.2Sb(y = 0, 0.02, 0.04, 0.06) ternary solid solutions were prepared by B2O3 flux method followed by spark plasma sintering (SPS) technique. X-ray diffraction analysis and scanning electron microscopy observations show that all samples are composites containing both major InSb-rich solution phase and minor GaSb-rich solution phase. We found that increasing In excess content markedly increased the Seebeck coefficient while had a weak influence on the electrical conductivity of In0.8Ga0.2Sb. As a result, a maximum power factor of 5.2 mWm−1 K−2 was obtained for y = 0.06 at 680 K, two times that of the y = 0 sample. Ga alloying obviously reduces the lattice thermal conductivity. The lowest lattice thermal conductivity of 1.98 Wm−1 K−1 was obtained in the sample with y = 0 at 776 K. The phonon scattering mechanism was discussed. Due to the highest Seebeck coefficient, the maximum ZT value of 0.9 was obtained at 770 K for y = 0.06, which is one of the best results for (In, Ga)Sb based TE materials, suggesting application perspectives at intermediate temperatures. These results also demonstrate the crucial importance of controlling the In stoichiometry in the (In, Ga)Sb solid solutions to obtain high TE performance.

Comparison of Sn-Sb and Sn-Ag-Cu-Ni-Ge Alloys Using Tensile Properties of Miniature Size Specimens

Tensile properties of Sn-5Sb (mass%) and Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge (mass%) were investigated using miniature size specimens and obtained results were compared. Tensile strength of both alloys increase with increasing the strain rate and decrease with increasing the temperature. Although similar dependency to the temperature is observed in 0.1% proof stress, the effect of the strain rate on it is obscure. The tensile strength and the 0.1% proof stress of Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge are higher than those of Sn-5Sb. The elongation of Sn-5Sb is relatively stable at the range from 0.4 to 0.6. The elongation of Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge which is approximately 0.3, is inferior to that of Sn-5Sb. On the basis of investigation of stress exponent, n, it was clarified that dispersion strengthening by Ag3Sn particulates in Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge is effective to prevent the degradation of creep resistance compared with Sn-5Sb that is strengthened by solid-solution of Sb in β-Sn phases and dispersion of SbSn compounds.

ВЛИЯНИЕ СВЕТА НА ПРОВОДИМОСТЬ И ПРОЦЕССЫ АДСОРБЦИИ–ДЕСОРБЦИИ АКЦЕПТОРОВ НА ПОВЕРХНОСТИ ТОНКИХ ПЛЕНОК СdTe:Sb

Изучено влияние внешних факторов (атмосфера, освещение) на проводимость тонких пленок CdTe:Sb. Обнаружено, что на зависимости действительной части комплексной электрической проводимости σ*=σ'+jσ''от времени под действием света с энергией кванта больше Eg наблюдается две области: резкий рост на начальном этапе и последующий спад. Показано, что наблюдаемый эффект снижения проводимости под действием света обусловлен фотодесорбцией молекул кислорода и/или воды с поверхности образца. Предложена модель «двуслойной» проводимости, представляющей собой цепь с «параллельно» соединёнными поверхностной и объемной проводимостью.&#x0D; Авторы выражают признательность к. х. н. Гапановичу М. В. за помощь в приготовлении образцов.&#x0D; Работа выполнена при финансовой поддержке проекта РФФИ № 16-08-01234 и госзадания № 01201361850.

The Influence of Processing on Strengthening Mechanisms in Pb-Free Solder Joints

The number, and the spacing, of Ag3Sn precipitates in Sn-Ag-Cu/Cu solder joints were related to separate processing parameters. The mechanical properties of an individual solder joint were directly related to the resulting distribution of different dispersoids in the joint. As the number of Ag3Sn precipitates increased, so did solder joint strength and shear fatigue lifetime. The room-temperature shear fatigue lifetime was inversely correlated with the separation between Ag3Sn precipitates. Bi and Sb solid solution strengthening was found to result in significantly larger values of shear strength and shear fatigue lifetime for one Pb-free solder. Room-temperature shear fatigue lifetime tests were identified as a relatively straightforward, yet sensitive means to gain insight into the reliability of Sn-Ag-Cu (SAC) solder joints.

Устройство для бесконтактного экспресс-измерения параметров термоэлектрических материалов

The paper presents an original method for contactless express measurement of parameters of thermoelectric materials. The presence of a combination of AC and DC magnetic fields in the gap of the oscillating circuit, where the monitored sample of the thermoelectric material is located, leads — due to Ampère force — to delamination of geometric regions of the occurrence of half-cycles of Foucault current. This in turn causes the appearance of additional heat losses in the oscillating circuit caused by Peltier effect. Computer modeling of these processes with the use of the software package ComsolFenlab 3.3 allowed determining the nature and magnitude of the electric currents in oscillating circuit, the range of operating frequencies, and the ratio of amplitudes of the variable and fixed components of the magnetic field. These components eventually cause a certain temperature difference along the controlled sample, which difference is proportional to the thermoelectric figure of merit Z of the material. The basic expressions are obtained for determining the value of the Seebeck coefficient a, thermal conductivity χ, electrical conductivity σ and thermoelectric figure of merit Z. A description is given to the design of the device for contactless express measurement of parameters of thermoelectric materials based on Bi—Te—Se—Sb solid solutions. Its distinctive feature is the ability to determine the symmetric and asymmetric components of the electric conductivity of the material values. The actual error in parameter measurement in this case is 2%.

Thermoelectric properties of the Ca(5)Al(2-x)In(x)Sb(6) solid solution.

Zintl phases are attractive for thermoelectric applications due to their complex structures and bonding environments. The Zintl compounds Ca(5)Al(2)In(x)Sb(6)and Ca(5)Al(2)In(x)Sb(6) have both been shown to have promising thermoelectric properties, with zT values of 0.6 and 0.7, respectively, when doped to control the carrier concentration. Alloying can often be used to further improve thermoelectric materials in cases when the decrease in lattice thermal conductivity outweighs reductions to the electronic mobility. Here we present the high temperature thermoelectric properties of the Ca(5)Al(2-x)In(x)Sb(6)solid solution. Undoped and optimally Zn-doped samples were investigated. X-ray diffraction confirms that a full solid solution exists between the Al and In end-members. We find that the Al : In ratio does not greatly influence the carrier concentration or Seebeck effect. The primary effect of alloying is thus increased scattering of both charge carriers and phonons, leading to significantly reduced electronic mobility and lattice thermal conductivity at room temperature. Ultimately, the figure of merit is unaffected by alloying in this system, due to the competing effects of reduced mobility and lattice thermal conductivity.

Preparation and characterization of (MnZn)1 − x Fe x Sb solid solutions with the Cu2Sb structure

(MnZn)1 − x Fe x Sb solid solutions with the Cu2Sb structure have been prepared through heterophase reactions. Their stability range is 0 < x ≤ 0.2. The magnetic interaction in the solid solutions has a ferromagnetic character. The Curie temperature and mass magnetization of the solid solutions have been determined, and the iron dopant has been shown not to participate in magnetic interaction.

X-ray diffraction determination of the composition of In x Ga1 − x Sb solid solution

A procedure to determine the composition of InxGa1 − xSb solid solution by X-ray diffraction is described. In order to calculate the indium content in a solid solution, an expression is proposed which relates the cell size of an undeformed layer with the dimensions of a tetragonally distorted unit cell of the layer under strain caused by a discrepancy in the dimensions of the layer and substrate lattices. The procedure yields results that well agree with measurements of the solid solution composition in a layer by energy dispersive spectroscopic control performed using an electron microscope.