Sn Solid Solution Research Articles

Improved Ammonolytic Synthesis, Structure Determination, Electronic Structure, and Magnetic Properties of the Solid Solution Sn(x)Fe(4-x)N (0 ≤ x ≤ 0.9).

We report a synthetic and theoretical study of the solid solution Sn(x)Fe(4-x)N (0 ≤ x ≤ 0.9). A previously published ammonolytic synthesis was successfully modified to achieve the metastable nitrides in phase-pure quality out of many competing phases. As TG-DSC measurements show, the thermal stability of the nitrides increases with increasing tin content. The Sn(x)Fe(4-x)N series of compounds adopts an antiperovskite-like structure in space group Pm3̅m. Various experimental and theoretical methods provide evidence that the iron substitution by tin exclusively takes place at Wyckoff position 1a and leads to a Vegard-type behavior of the lattice parameter over the compositional range, with an expection for a small internal miscibility gap around Sn(0.33)Fe(3.67)N of unknown cause. For highly tin-substituted iron nitrides the composition was clarified by prompt gamma-ray activation analysis (PGAA) and determined as Sn(0.78(3))Fe(3.22(4))N(0.95(3)) evidencing a fully occupied nitrogen position. Magnetic measurements reveal a linear weakening of ferromagnetic interactions with increasing tin concentration.

In Situ Visualization of Metallurgical Reactions in Nanoscale Cu/Sn Diffusion Couples

The Cu–Sn metallurgical soldering reaction in two-segmented Cu–Sn nanowires is studied by in situ transmission electron microscopy. By varying the relative lengths of Cu and Sn segments, we show that the metallurgical reaction results in a Cu–Sn solid solution for small Sn/Cu length ratio while Cu–Sn intermetallic compounds (IMCs) for larger Sn/Cu length ratios. Upon heating the nanowires to ∼500 °C, two phase transformation pathways occur, η-Cu6Sn5 → e-Cu3Sn → δ-Cu41Sn11 for nanowires with a long Cu segment and η-Cu6Sn5 → e-Cu3Sn → γ-Cu3Sn with a short Cu segment. The evolution of Kirkendall voids in the nanowires demonstrates that Cu diffuses faster than Sn in IMCs. Void growth results in the nanowire breakage that shuts off the inter-diffusion of Cu and Sn and thus leads to changes in the phase transformation pathway in the IMCs.

Synthesis, Characterization, and Gas-Sensing Properties of Mesoporous Nanocrystalline Sn(x)Ti(1-x)O2.

A nanocomposite mesoporous material composed by SnO2 and TiO2 with the size of -5-9 nm were prepared via a facile wet-chemical approach combining with an annealing process. The microstructure of obtained Sn(x)Ti(1-x)O2 powders were characterized by X-ray diffraction, X-ray Photo-electronic Spectroscopy, scanning electron microscope, transmission electron microscope and nitrogen adsorption-desorption experiment. The gas sensing performances to several gases of the mesoporous material were studied. The sensors of Sn(x)Ti(1-x)O2 (ST10, with 9.1% Ti) exhibited very high responses to volatile organic compounds at 160 degrees C. The order of the responses to volatile gases based on ST10 was ethanol > formaldehyde > acetone > toluene > benzene > methane. Sensor based on ST10 displays a highest sensitivity to hydrogen at 200 degrees C. Sensor responses to H2 at 200 degrees C have been measured and analyzed in a wide concentration range from 5 to 2000 ppm. The solid solution Sn(x)Ti(1-x)O2 can be served as a potential gas-sensing material for a broad range of future sensor applications.

Microstructure and properties of joint for stirring brazing of dissimilar Al/Mg alloy during heating processes

In this paper, 2024 Al alloy and AZ31B Mg alloy were brazed with aid of stirring without flux in air. The effects of the brazing temperature on microstructure and shear strength of the joint were investigated. The diffusion zone is found at joint interface near Al base metal, which consists of Al–Zn–Sn solid solution. At the same time, continuous intermetallic compounds (IMCs) phase and broken ones are found at joint interface near Mg base metal, which mainly consists of the Mg2Sn phase. With the increase of the brazing temperature, the shear strength at the joint interface near Al base metal rises gradually. On the contrary, that of the joint interface near Mg base metal obviously decreases.

Thermal stability of barrierless Cu–Ni–Sn films

To increase the thermal stability against interface reaction, barrierless Cu–Ni–Sn seed layers, with compositions formulated according to the cluster-plus-glue-atom model for stable solid solutions, was investigated in this paper. In this model, Sn is dissolved in Cu via Ni which is soluble both with Cu and with Sn, and the stable solid solution is formulated as [Sn–Ni12]Cux, where the Sn-centered [Sn–Ni12] octahedral clusters are embedded in an FCC Cu matrix of x atoms. Cu–Ni–Sn films with various Ni/Sn ratios were deposited onto the Si(100) substrate by magnetron sputtering and were characterized for microstructure and for electrical resistivity. The (Sn1.1/13.1Ni12/13.1)0.3Cu99.7 (at.%) film, with its Ni/Sn composition ratio being close to the ideal 12/1 value of the model, showed the minimum electrical resistivity of 2.7μΩcm on 500°C/1h annealing among all the samples. The resistivity maintained as low as 2.8μΩcm even after 400°C/40h annealing. No Cu silicide was observed by XRD and TEM in this sample, though a minute amount of fine Cu–Sn compound precipitates was present. The superior diffusion inhibiting effect was attributed to Sn in solid solution via intermediate of Ni.

Interfacial structure and fracture behavior of 6061 Al and MAO-6061 Al direct active soldered with Sn–Ag–Ti active solder

Micro-arc oxidation (MAO), a novel coating method capable of depositing compact, ultra-hard ceramic composite coatings on Al and its alloys, is applied to heat sink surfaces. A micro-porous Al2O3 layer was synthesized on 6061 Al-Alloy (MAO–Al) using the MAO technique. The microstructure, shear strength and fracture of Al/Al, MAO–Al/MAO–Al, and Al/MAO–Al joints were determined after direct active soldering in air with the Sn3.5Ag4Ti(Ce) active solder at 250°C for 30s. During active soldering, Al dissolves into SAT solder to form a coarse Al–Ag–Sn solid solution around the solder. Also, the active element Ti concentrates to and reacts with the MAO–Al layer to form both Ti-oxidized (e.g., TiO and TiO2) or rich-Ti(Al,Sn)3, and subsequently Ag3Sn nanoparticles are adsorbed at the solder/MAO–Al interfaces. The shear-tested bonding strengths were 15.3±1.38MPa for Al/Al, 10.45±1.53MPa for MAO–Al/Al, and 8.25±1.53MPa for MAO–Al/MAO–Al joints. In the Al/Al specimen, the fracture occurred in Al–Ag–Sn compounds of the active matrix after shear testing. In the MAO–Al/MAO–Al and MAO–Al/Al specimens, the fracture occurred in the MAO–Al/active solder interface.

Precipitation of DO19 type metastable phase in Mg–Sn alloy

Formation of metastable precipitates in the binary Mg–Sn alloy has been investigated in the present study. The Mg–1.5at%Sn solid solution alloy exhibits two exothermic reactions during heating up to 673K, where lower temperature reaction with onset temperature of 364K corresponds to the formation of metastable DO19 type precipitates, while higher temperature reaction with onset temperature of 466K to the formation of stable Mg2Sn precipitates. The comparison of aging behavior at 423K and 473K indicates that lower temperature aging at 423K results in retardation of peak aging time, but higher peak hardness due to the precipitation of DO19 type phase.

Microwave dielectric properties of (Ca0.8Sr0.2)(SnxTi1−x)O3 ceramics

Abstract In this paper, we study the behavior of the B-site behavior with the incorporation of Sn 4+ ion in (Ca 0.8 Sr 0.2 )TiO 3 ceramics. An excess of Sn 4+ resulted in the formation of a secondary phase of CaSnO 3 and SrSnO 3 affecting the microwave dielectric properties of the (Ca 0.8 Sr 0.2 )(Sn x Ti 1− x )O 3 ceramics. The dielectric properties of the (Ca 0.8 Sr 0.2 )(Sn x Ti 1− x )O 3 ceramics were improved because of the solid solution of Sn 4+ substitution in the B-site. The temperature coefficient of resonant frequency ( τ f ) of the (Ca 0.8 Sr 0.2 )(Sn x Ti 1− x )O 3 ceramics also improved with increasing Sn content.

Mechanosynthesis of supersaturated solid solutions of Sn in near-equiatomic bcc FeCo

The mechanosynthesis of Fe–Co–Sn ternary alloys from initial powder mixtures of composition (Fe50−x/2Co50−x/2)Snx is studied for x≤33at.%. Disordered nanocrystalline bcc solid solutions are formed in that way up to Sn contents as large as ∼20at.%. The dissolution of Sn in near-equiatomic bcc Fe–Co is unambiguously proven by X-ray diffraction and 57Fe and 119Sn Mössbauer spectroscopy.

Interface between Sn–Sb–Cu solder and copper substrate

Influence of antimony and copper in Sn–Sb–Cu solder on the melting and solidification temperatures and on the microstructure of the interface between the solder and copper substrate after wetting the substrate at 623 K for 1800 s were studied. Microstructure of the interface between the solder and copper substrates in Cu–solder–Cu joints prepared at the same temperature for 1800 s was observed and shear strength of the joints was measured. Influence of the atmosphere – air with the flux and deoxidising N 2 + 10H 2 gas – was taken into account. Thermal stability and microstructure were studied by differential scanning calorimetry (DSC), light microscopy, scanning electron microscopy (SEM) with energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD). Melting and solidification temperatures of the solders were determined. An interfacial transition zone was formed by diffusion reaction between solid copper and liquid solder. At the interface Cu 3Sn and Cu 6Sn 5 phases arise. Cu 3Sn is adjacent to the Cu substrate and its thickness decreases with increasing the amount of copper in solder. Scallop Cu 6Sn 5 phase is formed also inside the solder drop. The solid solution Sn(Sb) and SbSn phase compose the interior of the solder drop. Shear strength of the joints measured by push-off method decreases with increasing Sb concentration. Copper in the solder shows even bigger negative effect on the strength.

Congenerous and heterogeneous brazing of porous FeAl intermetallics

Congenerous and heterogeneous brazing of porous FeAl intermetallics has been successfully realised using Cu–10Sn green compact as brazing filler. Cu–Sn intermetallic phases combined with (Cu,Sn) solid solution were formed in the brazing line for congenerous brazing, while (Cu,Sn) solid solution was the main phase formed for heterogeneous brazing. Maximum tensile strengths for congenerous and heterogeneous brazing are 75·0 and 83·9 MPa which are about 81·5 and 91·2% of that of porous FeAl alloy (∼92·0 Mpa) respectively. The interface structure of the stainless steel and porous FeAl joint brazed at 940°C for 15 min is S–S+(Cu,Sn)/(Cu,Sn)/Cu9Al4+(Cu,Fe)+(Cu,Sn)/AlFe3+Al4Cu9+(Cu,Sn). In the porous FeAl and porous FeAl joint brazed with Cu–10Sn filler at 940°C, Cu–Sn intermetallics and (Cu,Sn) solid solution were the main phases in the joint line.

Correlation between Structural and Semiconductor−Metal Changes and Extreme Conditions Materials Chemistry in Ge−Sn

High pressure and temperature experiments on Ge-Sn mixtures to 24 GPa and 2000 K reveal segregation of Sn from Ge below 10 GPa whereas Ge-Sn agglomerates persist above 10 GPa regardless of heat treatment. At 10 GPa Ge reacts with Sn to form a tetragonal P4(3)2(1)2 Ge(0.9)Sn(0.1) solid solution on recovery, of interest for optoelectronic applications. Using electron diffraction and scanning electron microscopy measurements in conjunction with a series of tailored experiments promoting equilibrium and kinetically hindered synthetic conditions, we provide a step by step correlation between the semiconductor-metal and structural changes of the solid and liquid states of the two elements, and whether they segregate, mix or react upon compression. We identify depletion zones as an effective monitor for whether the process is moving toward reaction or segregation. This work hence also serves as a reference for interpretation of complex agglomerates and for developing successful synthesis conditions for new materials using extremes of pressure and temperature.

Electrodeposition of Palladium–Tin Alloys from 1-Ethyl-3-methylimidazolium Chloride–Tetrafluoroborate Ionic Liquid for Ethanol Electro-Oxidation

Electrodeposition of palladium–tin alloys from 1-ethyl-3-ethylimidazolium chloride–tetrafluoroborate ionic liquid was studied at . Sn(II) chloride reacts spontaneously with Pd(II) chloride, producing Sn(IV) and Pd nanoparticles. Solutions containing Sn(IV) and Pd(II) were used for potentiostatic electrodeposition of Pd–Sn. The composition of the Pd–Sn electrodeposits varied with the solution composition and deposition potential. Different alloy phases were observed with X-ray diffraction measurements. Whereas the Pd-rich Pd–Sn solid solution deposits are composed of compact nodules, the Sn-rich intermetallic Pd–Sn deposits are composed of polyhedral crystals of various phases. Compared to Pd-coated electrodes, Pd–Sn solid-solution-coated electrodes show enhanced ethanol electro-oxidation efficiency and stability in alkaline aqueous solutions. As Sn content increased, new Pd/Sn intermetallic phases formed, resulting in reduced catalytic efficiency for ethanol oxidation.

Study of thermal stabilization of an intermetallic compound-α-Fe(Sn) solid solution layered system

Mossbauer spectroscopy at 119Sn and 57Fe nuclei was used to study thermally induced processes of phase formation in two-layered systems Sn(4 μm)-Fe(10 μm) obtained by ion-plasma deposition. The layered systems were subjected to sequential isothermal annealings at 550°C and 700°C to show the formation of intermetallic compounds FeSn and Fe3Sn2 and of an α-Fe(Sn) solid solution. It has also been shown that the nature of the phase transformations is determined by a change in the local concentration of tin in the sample in the process of diffusion of the atomic components. Thermally stable spatially inhomogeneous systems FeSn/α-Fe(Sn) and Fe3Sn2/α-Fe(Sn) have been obtained.

ON THE SKUTTERUDITE Pt4Sn4.4Sb7.6

Pt 4 Sn 4.4 Sb 7.6 ( a = 9.3304(2) Å, space group [Formula: see text] ) is an unfilled skutterudite member of the solid solution Sn x Pt 4 Sn y Sb 12- x . In contrast to Sn x Ni 4 Sn y Sb 12- y and Sn x Pt 4 Sn y Sb 12- x no Sn could be found in the 2 a sites of the Sn / Sb framework. Physical properties have been data for Ni 4 Sn 3 Sb 9 and Ni 4 Sn 3.5 Sb 8.5. Resistivity measurements for Pt 4 Sn 4.4 Sb 7.6 reveal a temperature dependent crossover from metallic to semiconducting behaviour connected with a corresponding change from negative to positive thermopower at 30 K. Vicker's hardness, thermal expansion and elastic moduli compare well with values of other Sb - investigated in the temperature range from 4.2 K to 800 K and have been compared with based skutterudites.

Anodic Activation of Aluminum by Trace Element Tin

Trace elements in Group IIIA-VA activate aluminum alloys anodically in chloride environment. The present focus is on trace element Sn. Surface segregation by heat treatment and resulting surface activation on model AlSn alloys, containing 30 to 1000 ppm of Sn, were characterized, respectively, by use of surface-analytical and electrochemical techniques. Tin segregated by annealing for 1 h annealing at 300ºC, thereby causing significant activation, as characterized by pitting potential depression and high anodic currents produced. Activation was attributed to the segregated submicron particles. By increasing the annealing temperature to 600ºC, tin was incorporated in solid solution. This reduced surface activation to an insignificant level for the AlSn alloy containing 30 ppm Sn. However, alloy containing 1000 ppm Sn remained active. Removal of the active surface layers resulting from the segregation of the activating metals passivated the surface. However, Sn in solid solution affected the entire material.

Tuning between Mixing and Reactivity in the Ge−Sn System Using Pressure and Temperature

No bulk GeSn crystal existed prior to this work. Near 10 GPa the two elements resemble each other both electronically and structurally. Synthesis experiments at 10 GPa and 1500 K followed by annealing at 770 K using Ge and Sn starting materials and ex-situ analysis using transmission electron microscopy, scanning electron microscopy, and X-ray diffraction document the recovery of a Ge(0.9)Sn(0.1) solid solution (space group P4(3)2(1)2, a = 6.014 (1) A, c = 7.057 (1) A, Z = 12).

Magnetic properties of (Mn1 − x Fe x )1.68Sn solid solutions

Solid solutions in the (Mn1 − x Fe x )1.68Sn system (x ≤ 0.5) with a Ni2In-type structure are synthesized by the solid-phase reaction method in a stepwise temperature regime. The unit cell parameters a and c decrease with an increase in the iron concentration in the alloys and become equal to a = 0.430 nm and c = 0.538 nm for the (Mn0.5Fe0.5)1.68Sn alloy. A superstructure with the unit cell parameters a ss = 3a and c ss = c is revealed in alloys of the system under investigation. The specific magnetization of the alloys increases nonlinearly from 53 G cm3 g−1 in the Mn1.68Sn alloy to 72 G cm3 g−1 in the (Mn0.5Fe0.5)1.68Sn solid solution. The Curie temperature changes from 270 K in the initial alloy of the composition Mn1.68Sn to 365 K in the alloy of the composition (Mn0.5Fe0.5)1.68Sn. All solid solutions in the (Mn1 − x Fe x )1.68Sn (x ≤ 0.5) system exhibit metallic conductivity in the temperature range from 77 to 450 K.

A contribution to the phase diagram of the system Ge–Sn–Te and the conditions of (Sn, Ge)Te crystal growth

Phase relations in the GeTe–Te–SnTe region of the Ge–Sn–Te system have been studied with DTA, XRD and EPMA. In addition, a static method based on determination of composition of the solid and liquid phases at equilibrium at a given temperature was applied. The positions of the liquidus isotherms, the iso-mole-fraction lines which show the liquid composition at equilibrium with solid solution Sn 1− x Ge x Te of given x, and the two-phase crystallization lines for Sn 1− x Ge x Te + Te were determined. Finally, the conditions of Sn 1− x Ge x Te crystal growth from the melt by means of normal freezing and vapour–liquid–solid (VLS) technique yielding crystals with uniform distribution of GeTe mole fraction are discussed.

Thin layer in situ XRD of electrodeposited Ag/Sn and Ag/In for low-temperature isothermal diffusion soldering

In situ X-ray diffraction of thin electroplated Ag/Sn and Ag/In sandwich layers on Ni-coated copper substrates has been used to monitor the phase evolution in these systems at various temperatures. Initially, the course of the reactions in both systems, which are used in isothermal diffusion soldering, follows the transitions in their binary alloy phase diagrams. At 320 °C the composition of the reaction zone in the Ag/Sn case changes straightforward from tin-rich to silver-rich phases. In the case of Ag/In the same trend is observed, but the homogenization of the layer system is more complicated due to peritectic and metatectic reactions during heating up. The electroplated Ag/Sn and Ag/In ratios corresponded to the compositions of the respective ζ-phases. As the homogenization of the solder layers at 320 °C progressed, Ni–Sn and Ni–In phases were detected by EDX. The depletion of the Ag phases from Sn and In and formation of the solid solutions of Sn and In, respectively, in Ag were followed by in situ XRD. This technique allows studying the transformation of phases in thin layer sT:/PGN/ELSEVIER/META/web/00003803/ystems at process temperatures.