Formation Of Ternary Compound Research Articles

Spin coated La2CuO4 thin film: An extensive study on optical dispersion parameters

In this paper, a layered perovskite-type La2CuO4 thin film was deposited on quartz substrate using sol-gel spin coating technique. Though it is a well-studied material, the novelty of the proposed work is the technology adopted for the preparation of this thin film and extensive studies on optical dispersion parameters. The structural characterizations revealed the formation of pure phase ternary La2CuO4 compound with orthorhombic structure. The chemical state analysis detects the valance state of the constituent elements, La, Cu, and O as + 3, (+2,+1) and − 2 respectively. The average grain size was found to be nearly 115 nm from the FESEM images. The surface topography was studied using Atomic Force Microscopy and the root mean square roughness of the film was estimated as 20 nm. The optical studies indicated the semiconducting nature of the compound with a bandgap of 1.6 eV. The refractive index and extinction coefficient have been evaluated from the reflectance data. The linear and non-linear optical dispersion parameters are thoroughly studied using the Wemple and DiDomenico (WDD) single oscillator model. The linear dispersion parameters like the effective single oscillator energy, zero frequency refractive index, optical oscillator strength, and zero frequency dielectric constant have been estimated. Moreover, the nonlinear refractive index, optical susceptibility and optical moments were evaluated. The refractive index and third-order nonlinear susceptibility of La2CuO4 thin film were observed to be higher than some other materials reported in the literature. Thus, this study may be useful in designing La2CuO4-based high-performance devices for optical communications and integrated circuits.

High thermal conductivity of highly alloyed Mg-Zn-Cu alloy and its mechanism

The content of alloying elements in most thermally conductive magnesium alloys is as low as possible, and this will lead to lack of alloying effect. In this paper, a Mg-xZn-xCu(x = 1,3,5, wt%) alloy was studied with comparatively high alloying element contents. The thermal conductivity of this alloy declines very slowly with the increment of element concentration. Even with the additive amount of 10 wt% of alloying elements, this alloy can attain a high thermal conductivity of 136.5 W/(m·K). After T6 treatment, the thermal conductivity of Mg-5Zn-5Cu alloy increases to 141.6 W/(m·K). The CuMgZn intermetallic compound are specially prepared to study the thermal conduction mechanism. The results show that the formation of CuMgZn ternary compound in Mg-Zn-Cu alloy consumes massive solute atoms, which makes the thermal conductivity of the alloy insensitive to alloy composition changes.

High temperature thermal stability study of SrUF6(s) in SrF2-UF4 system

Fission of U(233) leads to produce number of fission products and among them Sr is one of the high yield fission product which form stable fluoride, SrF2. High temperature interaction of SrF2 and UF4 leads to formation of single ternary compound, SrUF6(s). The Gibbs energy formation of SrUF6(s) has been experimentally measured using two different calcium fluoride solid electrolyte Galvanic cell setup with common sample electrode and different reference electrode:Cell 1: (−)Pt, U3O8(s) ​+ ​UO2F2(s) ​+ ​SrUF6(s) ​+ ​SrF2(s) = CaF2(s) = NiO(s) ​+ ​NiF2(s), Pt (+)Cell 2: (−)Pt, SrO(s) ​+ ​SrF2(s) = CaF2(s) = U3O8(s) ​+ ​UO2F2(s) ​+ ​SrUF6(s) ​+ ​SraF2(s), Pt (+)Heat capacity and enthalpy increment has been experimentally measured with Differential Scanning Calorimeter and high temperature Calvet type drop calorimeter, respectively. The pseudo-binary phase diagram of SrF2-UF4 system was calculated by minimization of Gibbs energies of the phases present in the system. Before phase diagram calculation the experimental thermodynamic data were optimized. The stability domain of SrUF6(s) has been calculated from the chemical potential diagram of Sr–U–F–O system at 873 ​K as oxygen is present as an impurity in molten fluoride salts. The isothermal ternary phase diagram of Sr–U–F2 system has also been calculated in order to determine the coexisting phases of SrUF6(s) at 873 ​K.

Formation of the α''-phase and study of the solubility of Mn in Cd3As2

We studied the effect of Mn on the structure and properties of Cd3−xMnxAs2 crystals with x = 0–0.24, synthesized by direct fusion of high-purity elements. Obtained X-ray diffraction patters suggest that the incorporation of Mn promotes a structural phase transition from primary α-Cd3As2 (x = 0) phase to the α''– Cd3As2 (x = 0.24) phase, while at intermediate compositions both phases can coexist. In addition, the increase of Mn content results in the decrease of lattice cell parameters, which effectively saturates for x > 0.13. Microstructural, calorimetric and magnetometry studies suggest that at high Mn content (x = 0.24) secondary MnAs phase appears. Using obtained results, we estimated the solubility limit of Mn in Cd3As2 as x~0.13, which corresponds to the formation of ternary Cd3−xMnxAs2 compound where Cd atoms are partially substituted by Mn. Formation of ternary compound was also suggested by the results for Cd3As2 + MnAs composite systems, where we also observed the presence of CdAs2 phase, which is a byproduct of corresponding reaction. Additional studies suggested that the CdAs2 phase formation in composite system can be prevented if one uses the Cd3−xMnxAs2 compound instead of pure Cd3As2 as a matrix material.

Microstructure and mechanical characterisation of ECAP-ed ZE41A alloy

The ZE41A magnesium alloy is used mainly for aerospace and automotive applications owing to its moderate strength up to 150 °C. However, it shows reduced strength and ductility at ambient temperature as a consequence of formation of stable ternary compound on grain boundaries. Therefore, obtaining improved mechanical properties by grain refinement and changing the distribution and size of ternary phase using equal-channel angular pressing constitute the objectives of the present work. The microstructure after four passes of ECAP is characterised by bimodal grain distribution, with parts of ultrafine grains or subgrains below 1 μm, and elongated larger ones, even above 20 μm. The significant change in distribution and size of ternary phase occurred after ECAP. In addition, the Zn22Zr particles of approximately 50 nm in diameter and less were determined. These precipitates were not previously identified in the EZ41A alloy. The grain refinement, as well as the redistribution and the fragmentation of the ternary phase particles through a ECAP process is accompanied by an increase in mechanical properties. The hardness is almost two times higher after 4 passes of ECAP compared to as-cast condition. The tensile strength, as well as the compression strength approximately doubles and the ductility is enhanced.

The effect of pH and annealing temperature on TeMo5O16 ternary compound: investigation of structural and optical properties

In this paper, the TeMo5O16 ternary and MoO3-TeO2 binary compounds were prepared by using the solid-state reaction method and with MoO3-TeO2 oxide precursor solutions. The effect of pH and annealing temperature on the structure especially formation of TeMo5O16 ternary phase and optical properties of nanoparticles have been investigated. Ammonia (NH3) and nitric acid were used to adjust low and high pH, respectively. Synthesis and the formation of TeMo5O16 ternary compound were carried out at two processes: (A) chemical reduction with NaBH4 under nitrogen atmosphere and (B) annealing at temperatures T = 350 °C and 400 °C in air. These two temperatures were chosen because of the proximity to Te’s melting point. The results of X-ray diffraction showed that with increasing the annealing temperature, the MoO3-TeO2 binary composition is increased and an additional Te2O5 phase is observed. Also, with decreasing pH, the TeMo5O16 ternary phase is increased. The field emission scanning electron microscope (FE-SEM) images showed that the morphology of the nanoparticles is sphere-like, polyhedral forms, which indicates the presence of particles in different phases. The UV–Vis spectroscopy results showed that the energy gap of nanoparticles is varied in the range of 2.83–2.94 eV. The bonding structure of nano-particle was also studied by FT-IR spectroscopy.

Study on charge transportation and scaling behavior of CsPbI3 microwires

Cesium lead iodide (CsPbI3) has been prepared by a new experimental hazard free precipitation technique. X-ray diffraction spectra have been interpreted with Rietveld refinement which assures the orthorhombic phase of CsPbI3. Energy dispersive X-ray fluorescence spectra confirms the formation of ternary compound. Orthorhombic to cubic phase transition has been studied by observing hysteresis loop in R(T)-T plot for forward-reverse temperature scan. The intra-grain and inter-grain contribution of CsPbI3 to dielectric relaxation has been accounted by fitting the complex impedance plot (Cole-Cole plot). The value of FWHM in Z″(ω)-lnf or M″(ω)-lnf plot is greater than 1.141 decades which reveals the non-Debye type relaxation within material. The broad relaxation peak signifies that there is a distribution of relaxation time over a mean value. Moreover, Z″ & M″ have been plotted in scaled coordinate to check whether the distribution of relaxation time is temperature dependent or not. The frequency dependent relative permittivity represents the decreases of polarizations with frequency which have been successfully analyzed by Koop's theory. Here, activation energies are equal for different formalism, suggests that the same type charge carriers involved in conduction as well as relaxation process. Ac conductivity has been interpreted by using Jonncher's power law and frequency exponent (n) increases with temperature which suggests the presence small polaron hopping mechanism.

Thio-olivine Mn2SiS4 thin films by reactive magnetron sputtering: Structural and optical properties with insights from first principles calculations

Thio-olivines such as (Fe,Mn)2(Si,Ge)S4 have been proposed as candidate earth-abundant materials for single and multi-junction solar cells. In this work we present the first investigation of Mn2SiS4thin films prepared by reactive magnetron sputtering deposition, using a composition grading approach. Precursor instability in ambient conditions is observed, revealing the oxidation/hydrolysis of SiS bonds from the as-deposited film as a blocking mechanism for the ternary compound formation. Structural, morphological and optical properties of the annealed Mn2SiS4 films are reported for the first time. Resulting Mn2SiS4 films have orthorhombic Pnma structure and are polycrystalline. Raman active modes at 325 nm excitation are observed at 262, 320, 400 and 464 cm−1. From room temperature photoluminescence at 532 nm excitation the band gap is estimated to be about 1.9 eV, but a high optical absorption coefficient of >104 cm−1 was only obtained at E > 2.8 eV. First principles calculations are used for better understanding of opto-electronic properties. From the calculations, Mn2SiS4 is suggested to have a band gap of about 1.73–1.86 eV depending on the magnetic configuration of Mn and slight indirect nature. The slow absorption onset is interpreted by strong anisotropy due to one of the components of the dielectric function.

Covalent binding and fluorimetric determination of dialdehydes using aminated silica nanoparticles and ethylenediamine fluorescein

The possibility of formation of a ternary (sandwich) compound of a dialdehyde (malondialdehyde, glutaraldehyde, or glyoxal) with ethylenediamine fluorescein thiocarbamyl (EDF) and silica nanoparticles noncovalently modified with polyethyleneimine (SiO2/PEI) with the subsequent fluorimetric determination of the dialdehyde was demonstrated. The mixed Schiff base SiO2/PEI–dialdehyde–EDF (sandwich) is formed in an acetic acid solution on heating in a water bath. The sandwich and the excess of SiO2/PEI were separated from the unreacted fluorophore by centrifugation; the precipitate was washed and resuspended in water, and the fluorescence of solution was measured (λex = 470 nm, λem = 520 nm). The duration of an analytical cycle was no longer than a half-hour. The limit of detection of dialdehydes in pure water is 1 × 10–5 M, and the analytical concentration range is 2 × 10–5–3 × 10–4 M (for malondialdehyde). The repeatability RSDs in this concentration range were 3–5% (n = 3). The comparable concentrations of sulfamethoxazole, sulfadiazine, pyracetam, and chloramphenicol and 1 × 10–5 M of ceftriaxone, ceftazidime, metamizole (analgin), isoniazid, and amikacin caused no interference with the determination of 3 × 10–4 M malondialdehyde; protein noticeably interfered. The determination of glyoxal and glutaraldehyde in disinfectants was carried out.

Influence of pulsed electron-beam alloying with tantalum on structural phase states in TiNi alloy

The XRD and TEM investigations of gradient nano-, submicron- and microstructural states in the surface TiNi layers alloying by tantalum after pulsed electron-beam treatment was carried out. It was experimentally found that the modified TiNi surface area takes on a layered structure consisting of phases based on TiNi (B2, R and B19') and tantalum based phases (α-Ta, Ta2Ni and Ta2O5). The liquid-phase mixing of «Ta(film)/TiNi(substrate)» system resulted in phase formation of ternary compound (Ti,Ta)Ni with B2 and B19' structures.

Experimental investigation and thermodynamic calculation of the phase equilibria in the Mg-rich region of Mg-Sn-Y alloys

Phase diagram of Mg-Sn-Y ternary alloy systems were constructed thermodynamically using calculation of phase diagram (CALPHAD) approach. The thermodynamically calculated isothermal section of Mg-Sn-Y ternary alloy at 400 °C was validated by comparing with results reported in the literature and few selected key experiments. The calculated results matched well with the experimental results. Vertical section phase diagram of Mg-1Sn-xY and Mg-3Sn-xY alloys were constructed on the basis of solidification analysis and compared with thermodynamically calculated phase diagram. The thermodynamically calculated liquidus temperature for Mg-1Sn-xY system matched well with the experimental results. However, significant differences in solidus temperature and solubility limit were observed for Mg-1Sn-xY alloys. This difference is attributed to the shift in composition and temperature for L→L+α-Mg + Sn3Y5 and L→α-Mg + Sn3Y5+Mg24Y5 phase transformations. In Mg-3Sn-xY phase diagram, a gradual decrease in liquidus temperature is experimentally observed up to 13 wt % Y and further addition of Y leads to increase in liquidus temperature. The increase in liquidus temperature is attributed to the formation of MgSnY intermetallic compound which is not predicted by thermodynamic model. The lack of experimental data on the enthalpy of formation of ternary MgSnY compound is one of the major reasons for the discrepancy between the thermodynamic calculation and experimental results.

Deposition and characterisation of spray-deposited nanocrystalline Cd1−XZnXS thin films for photovoltaic device applications

Nanocrystalline Cd1−XZnXS thin films (X = 0.2, 0.4, 0.6, 0.8) have been grown on glass substrate by spray pyrolysis technique using equimolar concentration aqueous solution of cadmium chloride, zinc acetate and thiourea. Prepared thin films have been characterised by UV–vis spectrophotometer, X-ray diffractometer, SEM/EDAX analysis and two-point probe set-up. The optical band gap of the films has been studied by transmission spectra in wavelength range 325–600 nm. It has been observed that optical band gap increases with increasing zinc concentration. The X-ray diffraction pattern of films indicated that the films are polycrystalline with hexagonal grain structure. The lattice parameters of prepared Cd1−XZnXS films decrease with increase in zinc content. SEM/ EDAX analysis consolidates the formation of ternary compound. The DC electrical conductivity and activation energy of the films has been measured in vacuum by a two-point probe set-up. It has been observed that the electrical conductivity decreases with increasing Zn concentration in films.

Combined effect of strontium modifier and antimony refiner on texture and growth mode of eutectic phase in an Al-11Si-2Cu-0.8Zn-0.6Fe cast alloy

Results of electron back-scattered diffraction and transmission electron microscopy studies reveal that the orientation of aluminium in the eutectic phase is different from the surrounding aluminium dendrites and that twin spacing of eutectic silicon increased significantly due to the interaction between strontium and antimony. In addition, the formation of ternary Mg2Sb2Sr intermetallic compound that precedes the eutectic reaction was proposed to be responsible for interaction.

Interface evolution analysis of graded thermoelectric materials joined by low temperature sintering of nano-silver paste

Lead free solder Sn96.5Ag3.0Cu0.5 (SAC305) and nano-silver paste were used to connect graded thermoelectric (TE) arms, respectively. A series of harsh aging tests were carried out on joints of both p-type and n-type graded TE arms. The results showed that nano-silver paste printed by low-temperature joining technique was much more suitable for the stable connection of TE materials working in medium temperature range. 316 stainless steel and nickel were proved effectively as diffusion barrier layers in p-type junctions. While for n-type TE junctions, when aging at 300 °C, (Fe, Cr, Te) ternary alloy could be detected at Bi2Te2.7Se0.3/316 stainless steel interface. The formation of ternary compound realized fine metallurgical interconnection which was benefit for the improvement of joint strength. The average joint strength for p-type and n-type junctions in graded TE arms were above 20 MPa and 30 MPa, respectively.

Combinatorial Development of Fe-Co-Nb Thin Film Magnetic Nanocomposites.

A Fe-Co-Nb thin film materials library was deposited by combinatorial magnetron sputtering and investigated by high-throughput methods to identify new noncubic ferromagnetic phases, indicating that combinatorial experimentation is an efficient method to discover new ferromagnetic phases adequate for permanent magnet applications. Structural analysis indicated the formation of a new magnetic ternary compound (Fe,Co)3Nb with a hexagonal crystal structure (C36) embedded in an FeCo-based matrix. This nanocomposite exhibits characteristics of a two-phase ferromagnetic system, the so-called hard-soft nanocomposites, indicating that the new phase (Fe,Co)3Nb is ferromagnetic. Magnetic hysteresis loops at various angles revealed that the magnetization reversal process is governed by a domain wall pinning mechanism.

Influence of the indium nominal concentration in the formation of CuInS2 films grown by CBD

Copper indium disulfide (CuInS2) thin films were prepared by chemical bath deposition in an acid medium on glass substrates. CuInS2 films were grown using CuSO4, InCl3 and C2H5NS as copper, indium and sulfur sources, respectively. The CuSO4 and C2H5NS concentrations remained constant, while the InCl3 concentration was varied from 0.002M to 0.025M. The structural analysis show that initially the films have a mixture of CuS and CuInS2 phases, when the indium nominal concentration increases the formation of CuInS2 ternary compound was promoted until the final formation of a CuInS2 film. The morphological study shows that the surface of CuInS2 films is constituted by nanotubes. The structural and compositional analysis show that for 0.025M InCl3 concentration CuInS2 films were obtained.

Subsolidus phase equilibria and magnetic characterization of the pyrochlore in the Bi2O3–Fe2O3–Sb2O system

The subsolidus phase equilibria of the Bi2O3–Fe2O3–Sb2Ox system have been investigated by X-ray powder diffraction. The isothermal section of the system at 775–800 °C has been constructed. It can be represented by 9 phase assemblage triangles. Ternary compound formation is limited to pyrochlore which forms a substantial solid solution region of Bi-deficient compositions relative to Bi2FeSbO7. As follows from the phase diagram, approximately 7–25% of Bi positions in pyrochlore may be occupied with Fe3+ ions that was confirmed by Mossbauer data. Magnetic measurements were carried out on the pyrochlore specimen of quasi-chemical formula (Bi1.8Fe0.2)(FeSb)O7. The existence of the strong short-range antiferromagnetic superexchange interactions and spin-glass magnetic transition at around 9 K were revealed.

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF SICP/AZ91 MAGNESIUM MATRIX COMPOSITES PROCESSED BY STIR CASTING

Magnesium alloy (AZ91) matrix composites reinforced with various volume fractions of SiC-particulates were processed. A Stir casting process has been employed under an inert atmosphere to produce magnesium matrix composites. This process leads to a complete wetting of SiC particles in the molten magnesium. Microstructural feature, such as SiC particles distribution, and the interface between the magnesium matrix and SiC was characterized by scanning electron microscopy (SEM) and energy dispersion X-ray analysis (EDX). The results show a refined matrix structure of the composite compared to the matrix alloy, a uniform SiC distribution in the matrix and that no reaction takes place during the synthesis of the magnesium alloy matrix composites between the oxidized SiC and the molten magnesium. However, AZ91 matrix composite showed a massive formation of ternary intermetallic compound of Mg17 (ZnAl)12 at the SiC interface. The mechanical properties of AZ91 and AZ91-SiC composites have been evaluated and the results are compared with the unreinforced AZ91 alloy. Results of the mechanical properties revealed an increase in hardness value, maximum tensile strength and 0.2 % yielding strength. It was proposed that the strength increase due to SiC addition to AZ91 alloy was a result of a change in the matrix strength, i.e. an increase in dislocation density and a reduction of matrix grain size. However, it is also evident that the strain to failure significantly decreased as the volume fraction of the particulate increased. Examinations of the fracture surface show good bonding between SiC/matrix, extent of fine dimples, matrix cracking and particle cracking.

Crystallographic, optical and electrical properties of low zinc content cadmium zinc sulphide composite thin films for photovoltaic applications

In this paper a screen-printing method has been employed for the deposition of low zinc content cadmium zinc sulphide (Cd0.9Zn0.1S) composite thin films on ultra clean glass substrate. Cadmium sulphide, zinc sulphide and cadmium chloride have been used as the basic source material. With these basic source materials, the optimum conditions for preparing good quality screen-printed films have been found. X-ray diffraction studies revealed that the films are polycrystalline in nature, single phase exhibiting wurtzite (hexagonal) structure with strong preferential orientation of grains along the (101) direction. SEM/EDAX analysis confirms the formation of ternary compound. The optical band gap (Eg) of the films has been studied by using reflection spectra in wavelength range 350–600nm. The DC conductivity of the films has been measured in vacuum by a two probe technique.

Isothermal section of the iron-molybdenum-samarium system at 773 K

Component interactions in the iron-molybdenum-samarium system at 773 K were studied by powder X-ray diffraction, microstructure observation, electron probe microanalysis, and hardness and microhardness testing. The formation of a ternary intermetallic compound π with a ThMn12 structural type was found in this system. Binary intermetallc compounds were found to interact not only with one another to form two-phase equilibria ( Fe2Mo + Fe7Mo6, Sm2Fe17 + SmFe3, SmFe3 + SmFe2, and Fe2Mo6 + SmFe2) but also with pure components (Fe + Fe2Mo, Fe + Sm2Fe17, Mo + Fe7Mo6, Sm + SmFe2, and Sm + Fe7Mo6). Three-phase regions were also detected in th e isothermal section of the diagram: Fe + Fe2Mo + Ψ, Fe7Mo6 + Fe2Mo + Ψ, Fe7Mo6 + SmFe2 + Ψ, and SmFe3 + SmFe2 + Ψ.