Solid Solution Bi Research Articles

Mechanical property optimization of Sn-1.5Ag-0.5Cu solder alloys with additions of Bi, In, and Te

The mechanical characteristics of Sn-1.5Ag-0.5Cu (SAC155) alloy modified with In, Bi, and Te microalloying are investigated in relation to three strengthening mechanisms that withstand coarsening: (i) micron-scale Ag3Sn, Cu6Sn5, SnTe, Ag2In and InSn4 IMC precipitated phases, (ii) Bi in solid solution and (iii) Bi precipitated particles formed upon eutectic solidification. Compared to SAC155 alloy with a single strengthening mechanism, the combined effect of three deformation processes operating in SAC(155)-3Bi-2In with high In content and SAC(155)-3Bi-0.2Te (wt%) with low Te content alloys greatly improved the mechanical properties at high temperatures. It was found that, despite a discernible reduction in ductility, the high In content could refine the microstructure, enrich the elastic modulus (E), yield stress (YS), and ultimate tensile strength (UTS) of SAC(155)-3Bi-2In to almost 2.3 times that of SAC155 solder. On the other hand, a low Te content greatly increased SAC(155)-3Bi-0.2Te’s mechanical strength ∼2.3 times, while a large atomic size difference between Te and Sn atoms caused excessive misfit strain, which in turn increased Bi’s solubility in β-Sn grains, and improved ductility by approximately twice that of SAC(155)-3Bi-2In solder.

Challenging Fabrication and Characterization of a New Ferroelectric Solid-Solution Composition 0.30Bi(Cu1/2Ti1/2)O3 – 0.70PbTiO3

In this paper, an unexplored solid solution (1-x)Bi(Cu1/2Ti1/2)O3-(x)PbTiO3 has been synthesized and characterized for its crystal structure, dielectric and ferroelectric properties aimed at a selected composition, i.e., 0.30 Bi(Cu1/2Ti1/2)O3-0.70PbTiO3. The paper unveils the different synthesis approaches to achieve pure-phase in Pb-based perovskite-structured materials that are prone to produce impurities during synthesis. The Rietveld refinement of the XRD pattern confirms a tetragonal crystal structure (P4mm) of the composition. The ferroelectric properties of the as-prepared composition are also discussed using P-E hysteresis and PUND characteristics. The composition shows a high Tc (480 °C) and low dielectric losses, making it suitable for high-temperature applications.

Two Noncentrosymmetric Bismuth Phosphates: Rational Design Synthesis and Optical Properties.

Developing strategies to rational design noncentrosymmetric structure still attract much interest for their applications in nonlinear optical and piezoelectric materials. Two noncentrosymmetric (NCS) alkaline earth metal bismuth phosphates have been successfully achieved via partial replacement of Bi3+ with Ca2+ or Sr2+ ions. BiCa(H0.5PO4)2 (designated as CaBiPO) and BiSr(H0.5PO4)2 (designated as SrBiPO), together with their solid solution Bi(Sr1-xCax)(H0.5PO4)2 (0 < x ≤ 0.5), crystallize in the NCS space group C2. Both CaBiPO and SrBiPO exhibit ultraviolet nonlinear optical (NLO) properties, and their second-harmonic generation effects belong to type-II phase matching. Meanwhile, they could also act as photoluminescence hosts in which the Eu3+-doping samples SrBiPO:xEu3+ (x = 0.02-0.2) emit orange light. The effect of different radius ions on the derivative structures and the structure-NLO property relationship has also been discussed in detail.

Synthesis and Characterization of a New Ferroelectric with Low Lead Content, a High Curie Temperature, and a High Piezoelectric Response

AbstractA new solid solution (1−x)Bi(Fe2/8Ti3/8Mg3/8)O3–(x)PbTiO3 (BFTM‐PT) is synthesized and the electromechanical properties are measured. This system is defined as a low‐lead material with ferroelectric/piezoelectric behavior and a morphotropic phase boundary (MPB) that leads to enhanced properties. The MPB is located between x = 0.30 and 0.35 and coincides with a structural phase transition and a sharp increase in the piezoelectric response. The system demonstrates ferroelectric hysteresis where x = 0.325 displays the best properties with a maximum polarization of 39 µC cm−2 and a remnant polarization of 26 µC cm−2. The range of compositions has high Curie temperature (Tc), ranging from 625–650 °C. Materials with a Tc above 400 °C typically have a low d33 of &lt;50 pC N−1 at room temperature. However, BFTM‐PT has a higher d33 that most other compositions with a Tc in this range, with the highest being 145 pC N−1 for x = 0.375. The d33 drops off above 100 °C, but doping studies can be done in the future to stabilize the piezoelectric response at higher temperatures. These outstanding properties open the possibility of new transducer applications, in particular ones requiring high temperature and high power.

Reply to the 'Comment on "Structural, electrical and multiferroic characteristics of lead-free multiferroic: Bi(Co0.5Ti0.5)O3-BiFeO3 solid solution"' by P. E. Tomaszewski, RSC Adv., 2022, 12, DOI: 10.1039/D1RA08415A.

The cobalt and titanium modified BiFeO3 [i.e., Bi(Co0.40Ti0.40Fe0.20)O3; referred to as BCTF80/20] solid solution was synthesized via a simple and cost effective solid-state technique, and numerous sets of studies (structural, elemental, electrical, leakage current, multiferroic and other properties) were carried out and reported. The basic structural symmetry was investigated and phase identification of the prepared samples was carried out by analyzing powder X-ray diffraction data through the widely used "POWDMULT" software. From the XRD pattern [Fig. 2(a) of RSC Adv., 2018, 8, 36939], it is clear that almost all the reflection peaks (including those that appear to be split) have been indexed to a single phase (based on the best agreement between experimental and calculated interplanar distances and minimum standard deviation) system using the above software. The lattice parameters, average crystallite size, cell volume, and micro-strain value are strongly affected by the addition of Co and Ti into the bismuth ferrite. The significant enhancement of various parameter (i.e., electrical, multiferroic and so on) values of BCTF80/20 ceramics may make them promising candidates for the development of new generation electronic devices.

Solid Solution of Bi and Sb for Robust Lithium Storage Enabled by Consecutive Alloying Reaction.

Materials with alloying reactions have significant potential as electrodes for lithium-ion batteries (LIBs) due to its high theoretical capacity and appropriate lithiation potentials. Nonetheless, their cycling performance is inferior due to violent volume expansion and severe pulverization of active materials. Herein, solid solution of Bi0.5 Sb0.5 encapsulated with carbon is discovered to enable consecutive alloying reactions with manageable volume change, suitable for developing LIBs with high capacity and robust cyclability. A Sb-rich shell and Bi-rich core structure is formed in cycling since the alloying reaction between Sb and Li occurs first, followed by the alloying reaction between Bi and Li. Such a consecutive alloying reaction obeying the thermodynamic path is experimentally realized by the carbon capsulation, which acts as a protecting solid layer to avoid polarized reactions occurred when exposed directly to liquid electrolyte. The LIBs using Bi0.5 Sb0.5 @carbon run on the consecutive alloying reactions exhibits high capacity, prolonged lifespan (489.4 mAh g-1 after 2000 cycles at 1 A g-1 ) and fast kinetic, while those using bare Bi0.5 Sb0.5 suffer from worsened kinetic and thus a poor cycling performance owning to the polarized reactions. The work paves a way of developing alloy electrodes for alkaline-ion rechargeable batteries with potential industry applications.

Wettability, Interfacial Behavior and Joint Properties of Sn-15Bi Solder

Sn-15Bi solid solution solder provides a potential replacement for Sn-40Pb solder due to lower cost and similar melting point. Sn-15Bi solder was compared with Sn-40Pb solder to assess the microstructure, wettability, bulk tensile properties, interfacial microstructures in solder joints with a Cu substrate, the interfacial evolution in joints during isothermal aging, and the shear strength on ball solder joints with the effect of aging conditions. The microstructure of Sn-15Bi bulk solder was composed of the primary β-Sn phase with Bi in solid solution and with precipitated Bi phases along the grain boundaries. The wettability of solder alloys was evaluated with wetting balance testing, and the results showed that Sn-15Bi solder had a lower wetting force and longer wetting time than Sn-40Pb solder. The poorer wettability of Sn-15Bi solder was not influenced by different types of soldering flux, but improved with increasing temperature. Tensile tests on bulk solder alloys indicated that Sn-15Bi solder had a higher tensile strength but lower elongation than Sn-40Pb solder. Also, the tensile strength of Sn-Bi solder decreased with decreasing strain rate and with increasing temperature, while the elongation of Sn-Bi solder was independent of the temperature and strain rate. In as-soldered joints, Sn-15Bi solder produced a thicker Cu6Sn5 layer than Sn-40Pb solder. Following isothermal aging, the thickness of the interfacial Cu-Sn intermetallic compound (IMC) increased with the aging time, and the growth rate of the IMC layer in Sn-15Bi solder joints was slightly higher than that in Sn-40Pb solder joints during aging. Ball shear test on solder joints illustrated that Sn-15Bi solder joint had a higher shear strength than Sn-40Pb solder joint, and that with increased aging time, the solder became stronger due to precipitation of Bi, leading to a change in the fracture mode from ductile failure in the solder to brittle fracture at the IMC interface.

Structural Study and Electrical Properties of Bi1.5–xCaxSb1.5CuO7 Pyrochlore-Type Solid Solution Series

Abstract Pyrochlore solid solution Bi1.5−xCaxSb1.5CuO7 has been prepared by conventional ceramic solid state reaction with 0 ≤ x ≤ 0.4. The samples were characterized by X-ray powder diffraction (XRPD), scanning electron microscopy, and electrical conductivity measurements. The pyrochlore single phase formation was confirmed for all of the x-fractions. The variation of the electrical resistivity versus x of all samples measured by means of a four-probe device at room temperature indicates that these still remain insulators. High-temperature electrical conductivity measurements at various frequencies using a device with two electrodes allow us to note the maximum electrical conductivity of 4.7 × 10−3 S.cm−1, which has been reached at x = 0.2, generating an activation energy of 0.14 eV. For this fraction, Rietveld refinement of the corresponding XRPD pattern confirmed the typical cubic Fd-3m space group with a cell parameter of a = 10.4089(1) Å.

Криогенный термоэлектрический модуль для рабочего интервала температур ниже 90 K

It is considered the possibility of creating thermoelectric coolers for operating temperatures below 90 K. For these temperatures it is not possible to use a standard circuit of a thermoelement, consisting of two n- and p-semiconductor legs, connected in a series electrical circuit. In the area of cryogenic temperatures there is only an effective thermoelectric material of n-type conductivity, based on solid solutions Bi−Sb. In this case thermoelements composed of thermoelectric n-type leg and a passive leg, based on high temperature superconductor (HTSC) were studied. A thermoelectric cooler (module), consisting of six n-type legs (extruded crystals Bi0.91Sb0.09 ) and passive legs based on HTSC (YBa2Cu3O(7−x) ) films was designed. A magnetic field was used to increase thermoelectric figure of merit ZT of the cryogenic module. For created cryogenic module at hot side temperature Th = 80 K, a current I = 6.4 A and a voltage U = 0.10 V the maximum value of temperature drop &gt; 13.5 K and a maximum cooling capacity Qc &gt; 0.36 W were achieved.

Generation of near eutectic phase layer in Sn-15Bi solder joint during electro-migration

The electro-migration test of Sn-15Bi solder joint was conducted at 150°C with a current density of 160A/cm2. The near eutectic phase layer thickening as the extending of electro-migration time was observed on the anode side interface of Sn-15Bi solder joint. The Bi fraction of cathode side reduced as the increase of electro-migration time. The Bi atom of near eutectic phase layer was from solid solution Bi atom in β-Sn phase. The diffusion of Bi atom was up-hill diffusion under the effect of electron flow.

Bi(1-x)Ni(x)VO(4-y) Solid Solution with a High Visible-Light Photocatalytic Activity for Degradation Methyl Orange.

Particulate solid solutions Bi(1-x)Ni(x)VO(4-y) were synthesized by solid-state reaction at high temperature. The samples were characterized by X-ray Diffraction (XRD), Field-Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectrometer (EDS), Brunauer-Emmett-Teller (BET) surface area and Ultraviolet-Visible spectroscopy (UV-Vis). The photocatalytic activity of BiVO4 for photocatalytic degradation of organic contaminants ability in visible light region could be improved by doping of Ni(2+). The high visible light photocatalytic activity of Bi(1-x)Ni(x)VO(4-y) solid solution might be due to the generation of a new band gap and expanding the range of visible light response. It was suggested that the Ni(2+) doping was beneficial to effective charge separation of Bi(1-x)Ni(x)VO(4-y) solid solution, thus improved the photocatalytic activity.

Synthesis and characterization of new pyrochlore solid solution Bi1.5Sb1.5–xNbxCuO7

New pyrochlore solid solutions Bi 1.5 Sb 1.5– x Nb x CuO 7 have been synthesized (0 ≤ x ≤ 1.5) via the ceramic method in the air at 1000 °C. Rietveld refinement of the compounds Bi 1.5 Sb 1.5– x Nb x CuO 7 for x = 0, x = 0.75 and x = 1.5 by means of X-ray powder diffraction analysis confirmed an overall A 2 B 2 O 7 cubic pyrochlore structure according to (Bi 3+ 1.5 Cu 2+ 0.5 )(Sb 5+ 1.5– x Nb 5+ x Cu 2+ 0.5 )O 7 formula with 10.42009 (3) Å, 10.47193 (3) Å and 10.52679(4) Å, respectively, and F d 3 ¯ m space group. Composition dependencies of cell parameters show a linear increase with the niobium x fraction. The magnetic susceptibility measurements achieved between 4 and 400 K indicate a paramagnetic behavior with an oxidation state “+2” for the copper ion. The electric resistivity measured using complex impedance spectroscopy evidences an increase of the electric conductivity with temperature and niobium substitution.

Chemical Synthesis of Binary Solid Solution Bismuth–Antimony Nanoparticles with Control of Composition and Morphology

Abstract Three chemical synthesis approaches were developed to obtain binary solid solution Bi–Sb nanoparticles (NP) with controllable compositions and sizes. In each synthesis approach, an array of Bi100−xSbx NPs with x ranging from 25 to 90 was synthesized via careful control of feeding ratios and synthetic conditions. The NP sizes can be varied from 30 to 60 nm for single-crystal NPs, and from 350 to 500 nm for polycrystal NPs. The synthesized Bi100−xSbx NPs can be used as thermoelectric materials or as seeds for growth of ternary solid solution Bi–Sb–Te NPs with different compositions.

Morphotropic phase boundary and electrical properties of 1−x[Bi0.5Na0.5]TiO3 –xBa[Zr0.25Ti0.75]O3 lead-free piezoelectric ceramics

Abstract Lead-free solid solutions (1− x )Bi 0.5 Na 0.5 TiO 3 (BNT)– x BaZr 0.25 Ti 0.75 O 3 (BZT) ( x =0, 0.01, 0.03, 0.05, and 0.07) were prepared by the solid state reaction method. X-ray diffraction (XRD) and Rietveld refinement analyses of 1− x (BNT)– x (BZT) solid solution ceramic were employed to study the structure of these systems. A morphotropic phase boundary (MPB) between rhombohedral and cubic structures occured at the composition x =0.05. Raman spectroscopy exhibited a splitting of the (TO 3 ) mode at x =0.05 and confirmed the presence of MPB region. Scanning electron microcopy (SEM) images showed a change in the grain shape with the increase of BZT into the BNT matrix lattice. The temperature dependent dielectric study showed a gradual increase in dielectric constant up to x =0.05 and then decrease with further increase in BZT content. Maximum coercive field, remanent polarization and high piezoelectric constant were observed at x =0.05. Both the structural and electrical properties show that the solid solution has an MPB around x =0.05.

Bipolar piezoelectric fatigue of Bi(Zn0.5Ti0.5)O3-(Bi0.5K0.5)TiO3-(Bi0.5Na0.5)TiO3 Pb-free ceramics

The piezoelectric fatigue behavior of Pb-free ceramics based on solid solutions of Bi(Zn0.5Ti0.5)O3-(Bi0.5K0.5)TiO3-(Bi0.5Na0.5)TiO3 was characterized at 50 kV/cm after 106 bipolar cycles. Ferroelectric compositions containing 2.5% Bi(Zn0.5Ti0.5)O3 exhibited only minor losses in maximum strain (∼10%). In compositions with 5% Bi(Zn0.5Ti0.5)O3 that exhibit large electric field-induced strains, the electromechanical strain actually increased 4%, exhibiting essentially fatigue free behavior. This finding demonstrates that these materials have excellent potential for demanding high cycle applications such as microelectromechanical systems actuators.

ChemInform Abstract: Photocatalytic Water Splitting by Band‐Gap Engineering of Solid Solution Bi1‐xDyxVO4 and Bi0.5M0.5VO4 (M: La, Sm, Nd, Gd, Eu, Y).

AbstractTetragonal Bi1‐xDyxVO4 (0.3 ≤ x ≤ 1.0) solid solutions (prepared by solid state reaction at 1123 K for 12 h) split water into H2 and O2 simultaneously when loaded with 0.3 wt.% Pt or 1 wt.% Pt—Cr2O3 as cocatalyst.

Dielectric Properties of the Bismuth Neodymium Titanate Pyrochlore Solid Solution

The dielectric properties of a new, cubic, pyrochlore-type solid solution Bi(1.6−1.08x)NdxTi2O(6.4−0.11x) have been studied across the compositional range 0.35 < x < 0.86. The dielectric constant (ε) of the ceramics based on the pyrochlore-type solid solution within the experimental compositional range varied from 104 to 76 at 1 MHz, whereas the dielectric losses were well below tan δ = 8 × 10−3. The temperature coefficient of the dielectric constant τk for single-phase pyrochlore samples was found to be in the range between −20 and −40 ppm/K. Below room temperature dielectric relaxation phenomena were observed for all the compositions.

Mullite-derivative Bi2MnxAl7−xO14 (x∼ 1): structure determination by powder X-ray diffraction from a multi-phase sample

As a supplementary method to single crystal X-ray diffraction (XRD), nowadays crystal structure determination by powder XRD has become popular, especially for those areas with difficulties getting high quality single crystals. Here we observed an intermediate phase Bi(2)Mn(x)Al(7-x)O(14) (x~1) during the decomposition of mullite-Bi(2)Mn(x)Al(4-x)O(9+δ) (solid solution of Bi(2)Mn(4)O(10)-Bi(2)Al(4)O(9)). As a metastable phase, it started to decompose while forming, thus no single-phase sample can be obtained. We successfully determined its structure by powder XRD from a multi-phase sample. A modified Le Bail fitting using the atomic structure information of known impurities showed a more reliable intensity extraction from a multi-phase powder XRD than that without using atomic structures for the known impurities. The charge-flipping algorithm and Monte-Carlo based simulated annealing technique were then applied to obtain the full structural model. In principle, this strategy is applicable to more complex problems, and not limited to the oxide materials. Bi(2)Mn(x)Al(7-x)O(14) possesses a mullite-related structure. There are one tetrahedral and two octahedral sites for Mn and Al, where disordering with substantial site preferences is observed. Specifically, M1O(6) and M3O(6) octahedra share edges along the c-direction with the periodicity of 1 : 2. These octahedral chains are further connected into a 3D structure through M2O(4) dimmers and Bi.

Specific features in the synthesis, crystal structure and electrical conductivity of BICUTIVOX

The formation of solid solutions Bi 4V 2 − x Cu x/2 Ti x/2 O 11 − x (0.025 ≤ x ≤ 0.5) known as BICUTIVOX, synthesized by three different methods (a conventional solid-state synthesis, solid-state synthesis enhanced by mechanical activation, and through liquid precursors), has been studied. Based on crystal structure investigations carried out at different temperatures, ranges of stability and temperatures of phase transitions for different polymorphous modifications have been defined. The morphology and the local chemical composition of the ceramic samples obtained have been studied. Thermal expansion coefficients have been measured. The electrical conductivity of ceramic samples has been investigated in a wide range of temperatures and partial oxygen pressures.

New anion-conducting solid solutions Bi 1− xTe x(O,F) 2+ δ ( x > 0.5) and glass–ceramic material on their base

The anion-excess fluorite-like solid solutions with general composition Bi 1− x Te x (O,F) 2+ δ ( x > 0.5) have been synthesized by a solid state reaction of TeO 2, BiF 3 and Bi 2O 3 at 873 K with following quenching. The homogeneity areas and polymorphism of the I ↔ IV Bi 1− x Te x (O,F) 2+ δ phases were investigated. The crystal structure of the low temperature IV-Bi 1− x Te x (O,F) 2+ δ phase has been solved using electron diffraction and X-ray powder diffraction ( a = 11.53051(9) Å, S.G. Ia-3, R I = 0.046, R P = 0.041). Glass formation area in the Bi 2O 3–BiF 3–TeO 2 (10% TiO 2) system was investigated. IVBi 1− x Te x (O,F) 2+ δ phase starts to crystallize at short-time (0.5–3 h) annealing of oxyfluoride glasses at temperatures above T g (600–615 K). The ionic conductivity of the crystalline Bi 1− x Te x (O,F) 2+ δ phase and corresponding glass-ceramics was investigated. Activation energy of conductivity E a = 0.41(2) eV for the IV-Bi 1− x Te x (O,F) 2+ δ crystalline samples and E a = 0.73 eV for the glass-ceramic samples were obtained. Investigation of the oxyfluoride samples with a constant cation ratio demonstrates essential influence of excess fluorine anions on the ionic conductivity.