Sn Solid Solution Research Articles

Anomalous magnetism and electron paramagnetic resonance spectroscopy of the ZrNi1−xCrxSn solid solution

Abstract The static magnetic properties and electron paramagnetic resonance (EPR) spectra of ZrNi 1− x Cr x Sn solid solution (0 x ≤0.4) have been investigated in the temperature range 140–300 K. Materials were prepared by arc-melting of the pure metals. It was found that ferromagnetic ordering occurs in the samples with small chromium concentration. EPR spectra of the materials with x =0.05, 0.1, 0.2 consist of three absorption lines. The I and II lines are characterised by g =1.99±0.01, Δ H pp =(120±5) G type and g =1.980±0.001, peak-to-peak width Δ H pp =(10±1) G, respectively. They have been attributed to Cr 3+ ions in Ni-sites of the lattice coupled by magnetic dipolar interaction (type I) and to exchange coupled Cr 3+ pairs or clusters of more than two Cr 3+ ions (type II). The third line detected in the samples with x =0.3, 0.4 characterised by g eff =2.0003±0.0001 and Δ H pp =(3.0±0.5) G has been interpreted as conduction electron spin resonance (CESR).

Thermal stabilization of impurity and superconducting phase in superconductor

Tin-doped samples were synthesized in sealed silica tubes by a solid-state reaction method. The dominant phase involved in the sample is a superconducting phase of (Hg(Sn)-1223), which is a solid solution of Sn in the compound . An impurity phase also exists together with the dominant phase. The results of thermogravity analysis and XRD analysis show that the impurity phase and superconducting phase Hg(Sn)-1223 have different decomposition temperatures in flowing He gas and in flowing gas atmosphere. The onset decomposition temperatures of these two phases measured in flowing He gas are 560 and respectively. They increase to 576 and respectively in flowing gas. Studies of the effect of annealing temperature on by resistance measurement for this sample show that the superconductivity is reversible in flowing gas below the decomposition temperature of the superconducting phase Hg(Sn)-1223, namely . The quality of the superconductor, including the critical temperature and the sharpness of the transition, can be improved by removing the impurity phase from the sample using a high-temperature annealing process under flowing gas.

Solid State Reactions in the Fe-Sn System under Mechanical Alloying and Grinding

Structure-phase transformations in the 68Fe-32Sn system by mechanical alloying from pure elements and mechanical grinding of a multi-phase alloy for different conditions of mechanical treatment in planetary ball mills were studied by X-ray diffraction, 57 Fe Mossbauer spectroscopy and magnetic measurements. The initial stages of structure-phase transformations by mechanical alloying and grinding were found to be different. However, the final product in all cases was nanocrystalline supersaturated solid solution of Sn in α-Fe with the bcc lattice parameter a= 0.2995 nm, the magnetic moment per Fe atom μ Fe =1.9 μ B and the Curie temperature T c =700 K.

Structural-phase transition and electrical conductivity in tin-modified zirconium titanate

The structural phase transition in tin-modified zirconium titanate was investigated using high-temperature X-ray, DTA, DSC and electrical conductivity. In a dilute solid solution of Sn ( x ⩽ 0.2) in Zr 1− x Sn x TiO 4, we ascribed to the successive phase transition from normal to incommensurate the break of electrical conductivity, thermal anomalies, and specific heat anomalies occurring at temperatures of 1121 °C, 1124 °C and 1125 °C on the heating run, and at temperatures of 1121 °C, 1116 °C and 1117 °C on the cooling run, respectively. Furthermore, the super-lattice reflection intensity was inversely proportional to the Sn content, cooling rate and electrical activation energy. With a composition of Zr 0.8Sn 0.2TiO 4, the phase transition from normal to incommensurate was completely inhibited.

Nanosized Metallic Sn Precipitates in Si, Formed Upon Ion Implantation

AbstractIn this work we firstly established the optimal conditions to preferentially form nanosized β-Sn inclusions from a supersaturated solid solution of Sn in Si, formed by a high dose ion implantation. Afterwards we tried to elucidate the origin of the strongly enhanced recoilless fraction of Sn nuclei inside these precipitates, thereby making a link to the observed shift in isomer shift value. This is tentatively interpreted in terms of a local compression of the inclusion to about 200 kbar.

A Mössbauer spectroscopy study of nanoscale Ge–Sn dispersions prepared by ball milling

Nanoscale mixtures of Ge/Sn, a nominally immiscible binary system, prepared by mechanical attrition have been studied by 119Sn Mössbauer spectroscopy. The Mössbauer measurements in general reveal two sites for the Sn atoms, a tetragonal β–Sn site and another site designated as “A”. The β-Sn integrated intensity decreases in magnitude with Ge concentration, 1 – x, in Ge1−xSnx as the second A-site intensity increases. The isomer shift and the small/negligible quadrupole splitting of site A suggests it represents Sn in solid solution in the Ge lattice. This in turn represents a large (12–24 at. %) nonequilibrium solid solubility of Sn in Ge prepared by mechanical milling, compared to the equilibrium value of <1.0 at. %. Oxidation of the Sn was detected by Mössbauer spectroscopy at Sn-poor concentrations (x ⋚ 0.10) when the milling vial was not totally free of oxygen (i.e., milling in impure argon). This may be due to rapid oxidation of finely divided Sn film particles possessing a large surface-to-volume ratio at these compositions.

純アルミニウムの電気化学的挙動に及ぼすＳｎの影響

The surface analyses and the anodic polarization measurements on Al-0.01%Sn alloys heated at 823K for 6h have been carried out to investigate the relations between the electrochemical properties and the morphology of Sn at the surface layer. After the heating the fine Sn particles were uniformly distributed at the metal-oxide film interface. The rapid current increase was observed at two different potentials in the polarization curves on the alloys. They are attributed to the formation of two different potential layer due to the segregation of Sn at the surface, that is, the potential of surface layer is less noble that of inner one because of more amount of solid solution Sn in the former. On the other hand, the densely distributed finer shallow pits occured in the anodic dissolution at lower current density, the distribution of which approximately corresponded with that of precipitated Sn particles.

Equation of state for α-phase GeSn solid solution

The equation of state of α-phase solid solution for the GeSn system is studied using the electronic theory based on pseudo-potentials and the virtual crystal approximation. The calculated results of the pressure-volume relation for the α-phase Ge 1− x Sn x solid solution are not monotonic as a function of atomic fraction x, and show a softening of the crystal under compression contrary to those for pure β-Sn. The influence of Sn solubility in Ge on the pressure-induced α− β phase transition i calculated. In the region of x<0.2, where the formation of an α-phase Ge 1− x Sn x solid solution was predicted under pressure, the volume discontinuity ΔΩ solid solution was predicted under pressure, the volume P t remains to be almost, constant, and the latent heat of transition ΔE increases slightly with Sn solubility in Ge.

Prediction of α-phase GeSn solid solution under pressure

The compression effect on the phase diagrams of the GeSn and SiSn systems is investigated using the electronic theory based on pseudopotentials and the virtual crystal approximation for the disordered alloy. The hypothetical solid solution for the GeSn and SiSn systems undergoes a pressure-induced phase transition from the α-phase of substitutional diamond-type to β-phase of disordered white-tin-type. The heat of solution ΔE( χ, P) for Ge 1− x Sn x and Si 1− x Sn x systems under pressure P is large for the Sn-rich region and decreases as the crystal is compressed. Consequently, we predict the appearance of an α-phase solid solution for the GeSn system under pressure. The phase diagrams under pressure are obtained quantitatively. Because of the large heat of solution, the solid solution for the SiSn system is not formed under pressure.

Cyclic deformation and fracture in Pb-Sn solid solution alloy

The cyclic deformation behavior of Pb-2 pct Sn solid solution alloy has been investigated. Results indicate that grain boundary migration and sliding occur in a systematic manner, giving rise to a series of migration markings on the surface of deformed specimens. Extensive cracking and cavitation takes place at migrating boundaries leaving an array of microcavities at high strain amplitudes. This feature was not observed at the low strain amplitudes investigated. Dynamic recrystallization and the evolution of a diamond grain configuration from an initial random distribution of grains were observed. These microstructural observations are discussed in relation to their influence on high temperature fatigue fracture.

Cavitation at migrating boundaries during high temperature fatigue

There is growing interest in the role of migrating boundaries during high temperature deformation. One area of current interest is the manner in which grain boundary migration can influence deformation and fracture at elevated temperatures. Much of the detailed treatments of intergranular cracking and cavitation during creep deformation have centered on effects occurring at stationary grain boundaries. The conventional idea represented in numerous publications is that grain boundary sliding plays an important role in intergranular fracture at elevated temperatures. The large stress concentrations developed at irregularities on grain boundaries are frequently cited as the principal reason for the easy generation of cracks and cavities. This article concludes that high temperature fatigue can cause significant migration and sliding in Al-3% Mg and Pb-2% Sn solid solution alloys, and that microcavitation and cracking takes place at the migrating boundaries in specimens tested at large strain amplitudes and low test frequencies. Cavities may be isolated within grains due to boundary migration.

Solid solubility limits in ion-implanted gallium arsenide

High dose (4 × 10 14−1 × 10 16ions cm −2) implantation into (100) GaAs wafers of Sn, Sb and Te was carried out at either liquid N 2 temperature or at elevated temperature. Selected samples were capped with sputter deposited SiO 2 and annealed in the solid phase using either a furnace or a rapid incoherent light source. Uncapped samples were annealed using a pulsed ruby laser. Ion channeling of 2 MeV He 2+ indicated that solid solutions of Sn, Sb and Te in the range 10 20−10 21 cm −3 were obtained following 600°C annealing. The maximum measured solubility appeared to be limited by the solute-defect interactions and thus the ability to achieve acceptable crystallinity during annealing. For higher temperature and longer time furnace annealing the maximum solubility can either increase or decrease with temperature and is controlled by both solute trapping at residual defects and precipitation processes.

X-ray scattering structural investigation of Pt and Pt–Sn catalysts supported on nylon

The physical properties of Pt and Pt–Sn/Nylon catalysts have been determined using X-ray scattering techniques (SAXS and WAXS). Two different structural conditions of Pt/Nylon were inferred from the characterization. A large amount of the supported metal phase, ca. 100 Å in size, retains the Pt crystalline structure and appears to be embedded in the Nylon. A second fraction with a strong metal–ligand interaction is also present. Addition of tin to the Pt/Nylon system does not change the observed structural framework, although a Pt–Sn solid solution appears with a decrease in the size of the metallic phase.

Decomposition of supersaturated solid solution in splat-cooled Sn- 10 at% Sb alloy

A supersaturated solid solution was obtained in an Sn-10 at. %Sb alloy rapidly quenched from the liquid state. Decomposition of this solution, taking place during isothermal annealing at 373 K, was investigated by transmission electron microscopy. In the first stage of decomposition, clustering of Sb atoms in definite planes of the tetragonal lattice of tin was observed. Subsequently, needle-like precipitates of the equilibrium compound SnSb were formed. The sequence of decomposition of the supersaturated solid solution Sn(Sb) and a model for the formation of the compound within the tetragonal lattice of tin are proposed.

Interaction of cold work, recovery, recrystallization, and precipitation in heat-treatable copper alloys

Inhibition of recrystallization in copper and its alloys can be caused by small quantities of foreign elements such as Ag, P, Cd, Mg, and Sn in solid solution in the copper. These elements segregate at dislocation and grain boundaries, thereby inhibiting migration. The effect of cold work is a simple function of the quantity of soluble addition and the degree of cold work. The situation is more complicated for precipitation-hardened alloys because cold work, precipitation, and softening interact. In starting with the supersaturated solid solution which has been severely cold worked, heat treatment will lead to both precipitation and recrystallization. However, by means of precipitation treatment before cold working, it is possible to slow down, and even halt, normal recrystallization; this treatment leads to the formation of a critical distribution of precipitates ('dispersoid') which effectively halts both dislocation and grain-boundary movement. Cu–Ti, Cu–Zr, Cu–Fe, and Cu–Co alloys were studied for different sequences of heat treatment and cold working and the following characteristics are described: (a) a very small residual quantity of soluble Zr suffices to maintain the softening temperature above 400°–500°C; (b) soluble Cr also inhibits the softening of Cu, although larger amounts are required than for Zr,’ (c) fine precipitates of Cr in the form of a critical dispersion are also effective for retaining cold working; (d) iron in solid solution has practically no effect on the softening temperature of copper.

Aligned composite materials obtained by solid state decomposition

Aligned lamellar structures can be obtained by unidirectional heat control of eutectoid disproportionation and discontinuous precipition. Experimental data are reported concerning the eutectoids in the systems CoSi, NiIn, CuIn, CuAl, AlZn and the supersaturated solid solution of Sn in Pb. All the systems discussed give structures parallel to the direction of growth. Under certain conditions, however, the system CuAl shows a deviation in the direction of the lamellae with respect to the growth direction. In fact lamellae are formed simultaneously in two directions, throughtout the grains, resulting in a zigzag lamellar pattern. The directions of the lamellae appear to be independent of the direction of growth and the angle between them is 30°. The crystallographic data are given. The experimental relationship between interlamellar period (λ) and pulling rate ( R) in the NiIn system is found to be λ 4 R = constant, as in the CoSi system previously reported. Some physical properties of the materials obtained are also reported.

The preparation of aligned composite materials by unidirectional solid-state decomposition

Analogous to the alignment of lamellar eutectic structures by means of unidirectional solidification, the discontinuous decomposition of eutectoids and supersaturated solid solutions appears to yield aligned lamellar specimens under unidirectional cooling conditions. Experiments are described'concerning the eutectoids in the systems Co-Si, Cu-Al, Cu-In and Ni-In and the supersaturated solid solution of Sn in Pb. The lamellae occurring upon decomposition are parallel to the temperature gradient throughout the samples and parallel to each other over lengths of mm (Co-Si, Ni-In, Cu-Al, Pb-Sn) or cm (Cu-In). For the eutectoid decomposition of Co 3Si the experimental relationship between the interlamellar spacing λ (varying between 0.1 and 1 μm) and the decomposition rate R appears to be λ 4 R = constant. At relatively high rates (depending on the system) the parallelism of the lamellae is lost.

蒼鉛-錫系平衡状態圖に就て

Some investigators assumed the formation of BiSn7, Bi2Sn or BiSn2 in the solid of the alloys of the Bi-Sn system. To verify the formation of the intermetallic compound and to clarify the nature of the change in the solid state of this alloy system, the present study was carried out by differential thermal analysis, volumetric dilatation method, electrical resistance method, X-ray analysis and microscopic examination. In the curves of differential thermal analysis no discontinuities were observed, while in electrical resistance and volumetric dilatation curves one or two were observed. From these results, the solubility curve of Bi in Sn-solid solution was determined (Fig. 10). X-ray analysis by Seemann-Bohlin's method denied the existence of any intermetallic compound in this system. So the discontinuity appeared at about 95° in the curves of electrical resistance and volumetric dilatation is due to the abrupt change in solubility of Bi in Sn-solid solution, and not to the formation of any compound.