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Dual-cathode dc unbalanced magnetron sputtering for the deposition of ternary compound films with a high deposition rate was designed and constructed. It consists of two magnetrons of opposite magnetic polarities. Each magnetron consists of central and outer ring magnets with the residual inductions of 500 and 600 mT, respectively. The testing results of the system showed that high plasma volume could be created at a long substrate distance of about 15 cm from the targets. In addition, by using this sputtering system for coating TiAlN film, the result showed that at a target to substrate distance of 13 cm the film growth rate was 7.3 nm/min. It indicates that the sputtering system developed in this study is suitable for large substrate area coating due to the long distance of target to substrate.

The new ternary compound Y4Be33Pt16 was prepared from elements by arc melting, and its crystal structure was determined from single-crystal X-ray diffraction data (space group I4[combining macron]3d, a = 13.4849(3) A). The material is the first representative of a new structure type of complex intermetallic compounds and reveals a cage-like crystal structure. Analysis of chemical bonding by means of the electron localizabilty approach indicates ionic interaction of yttrium with the rest of the crystal structure, characteristic for cage compounds, in particular for clathrates. In contrast to the mostly two-centre bonding in the framework of clathrates, the new compound is characterized by a multi-centre interaction within the framework, caused by the demand of the valence electrons in the system. The non-centrosymmetric material enters the superconducting state at TC = 0.9 K.

The influence of Al on the thermoelectric properties of the half-Heusler (HH) TiNiSn compound is reported. The research combined ab initio Density Functional Theory (DFT) calculations with experimental microstructure evaluation and measurements of the transport properties up to 750 K. It is shown that Al addition to the Ti sub-lattice results in an increase of the absolute value of the Seebeck coefficient and electrical resistivity in polycrystalline TiNiSn, while preserving the n-type behavior of the ternary compound, in addition to a significant reduction of the thermal conductivity. In (Ti0.99Al0.01)NiSn, upon 1% Al substitution of Ti, an improvement of 17% in the thermoelectric figure of merit (0.42 at 723 K) compared to pure TiNiSn was observed. Theoretical lattice thermal conductivity calculations are applied to shed light on the different scattering mechanisms in this class of materials. It is shown that the major contribution to the lattice thermal conductivity reduction is stimulated by the presence of Sn-rich inclusions, in addition to an influence of mass fluctuation scattering due to substitution of Ti by Al. Although it is shown that in the widely applied polycrystalline TiNiSn, an addition of the acceptor Al dopant could not fully compensate n-type electronic active defects (e.g. grain boundaries) for obtaining p-type materials, the currently reported results pave a route for thermoelectric optimization of MNiSn (M = Ti, Ni, Sn) n-type half-Heusler compounds.

Cu1.45Ni1.45Te2 ternary compound was synthesized by solid-state ball-milling method and densified via spark plasma sintering (SPS) and cold-pressing with annealing (CPA) techniques. The effect of densification techniques on the thermoelectric properties was studied. SPS sample showed negative Seebeck coefficient values for the entire temperature range, while CPA sample changed the sign of the Seebeck coefficient above 573 K from n-type to p-type. The electrical conductivity was higher for SPS sample than for CPA sample for the entire temperature range. Hence, SPS sample exhibited 167% increased zT when compared to CPA sample. It is confirmed that the SPS technique is more suitable to obtain a high zT value than the CPA technique for n-type Cu1.45Ni1.45Te2 sample. Also, the effect of carrier concentration was studied and the change in the carrier concentration was done by Se-doping. From a series of thermoelectric measurements, it was found that the undoped sample exhibited a high zT of about 0.004 at 400 K and the Se-doped sample exhibited a zT of 0.001 at 750 K. It means that Se-doping mainly influences the shifting of the operating temperature of TE performance from room temperature range to mid-temperature range. The formation of n-type TE material was realized due to the delocalization of electron density on Te-ions, which compensate the Cu-vacancies resulting in the n-type conduction behaviour. Se-doping modifies the reaction of Te-ions with cations affecting the delocalization of electron density, which shifts the conduction type from n-type to p-type behaviour.

Pressure has become a useful parameter to prepare novel functional materials. Considering the excellent performance of ZnO and Zn3N2 and the formation of strong Zn–O, Zn–N, and N–O bonds in the known compounds, we explored potential Zn–N–O ternary compounds with interesting properties. With the aid of first-principles swarm-intelligence search calculations, we identified a hitherto unknown ZnN2O3 ternary compound with a symmetry of P21. Its remarkable feature is that N pairs interconnect the distorted Zn-centered decahedrons, in which the Zn atom forms bonds with one N and six O atoms. The compression of ZnO + NO2 + N2 might be an easy way to synthesize ZnN2O3. Electronic property calculations disclose that ZnN2O3 is a wide band gap semiconductor with a gap value of 3.48 eV, which is larger than those of ZnO and Zn3N2. Moreover, the high-pressure phase diagram of Zn–N binary compounds was explored with a wide range of chemical compositions. Two metallic N-rich zinc nitrides (e.g., ZnN2 and ZnN4) are proposed, containing intriguing N2 dimers and zigzag N chains. ZnN2 exhibits superconducting properties, and becomes the first example of superconductor in zinc nitrides. Our current results unravel the unusual stoichiometry of Zn–N–O compounds and provide further insight into the diverse electronic properties of zinc nitrides under high pressure.

The development of insensitive energetic composite materials is a research topic of growing interest. Nanothermites, which are described as a highly reactive mixture of metal and metal oxide, are the focus of this challenge. In this work, the conductive polymer polyaniline (PAni) was introduced into an Al/SnO2 energetic nanocomposite either via the preparation of a SnO2-PAni composite or as a powdered ternary compound. Both PAni-enriched Al/SnO2 nanothermites were characterized in terms of sensitivity (impact, friction, electrostatic discharge (ESD)) and reactive properties (combustion velocity). The two methods were compared to evaluate which one achieved the best compromise for the nanothermite in terms of performance (sensitivity/combustion properties). When the polymer is intimately structured with the oxide, it is possible to reduce the sensitivity of the energetic composition as a function of the additive amount. The polymer easily conducts the electrostatic charges through the energetic matter until the nanothermite presents no handling danger: ESD varied from 0.42 to 246.1 mJ for the safer composition (4.80 wt% of PAni). On the other hand, when PAni powder was added to the nanothermite, the ESD threshold did not vary because no continuous conductive phase was created within the material. Concerning the reactive properties of the Al/SnO2 energetic system, with the addition of PAni (2.04 wt%) as an SnO2-PAni hybrid matrix, the combustion velocity decreased from 800 to 500 m/s combined with a lower luminous signature. The use of a structured conductive polymer as a desensitizer within nanothermites, represents a significant step forward in the development of safer and reactive energetic compositions.

U3Si2C2 is expected to be a new nuclear fuel as a ternary compound of uranium, silicon and carbon. However, the relevant research on U3Si2C2 under accident conditions is rarely reported. Hence it is necessary to explore the service behavior of the potential U-Si-C ternary nuclear fuel in extreme environments. In this work, the structural characteristics, electronic behaviors and mechanical properties of U3Si2C2, such as stable crystalline structures, density of states, charge distributions, electron localization function, electronic thermal conductivity and elastic modulus under extreme high pressure are calculated by density functional theory. The calculation results show that the lattice volume sharply increases when the external stress reached 9.8 GPa. Ionic and metallic nature coexist as to the bonding characteristics of U3Si2C2, and the ionic takes the dominant position in bonding. The toughness of U3Si2C2 is predicted to be better compared to U3Si2. Our theoretical investigation may help with the application of U3Si2C2-based fuel and the design of ternary uranium fuels.

It is known that Ti 3 SiC 2 is the only stable ternary compound in the Ti-Si-C system that demonstrates a good microstructure-properties relationship. The production of Ti-C-Si by detonation spraying technique results in the formation of multilayer Ti 3 SiC 2 /TiC coating. This transformation is due to the deintercalation of Si from Ti 3 SiC 2 that enlarges after heat treatment. This article provides investigations on the effect of middle-temperature annealing on the structural-phase state, mechanical and tribological properties of Ti 3 SiC 2 /TiC coatings obtained by the detonation spraying method. After annealing, the formation of [110], [211] and [301] reflections of TiO 2 phases and an increase in the intensity of [103] and [108] reflections of Ti 3 SiC 2 phases are observed. The maximum hardness of 1400 HV obtained for the coating annealed to 800° C. A similar tendency observed during adhesion tests. An increase in annealing temperature to 800° C, improves the adhesion strength of the coating to 13.2 N. Meanwhile the value of COF remains stable for as-deposited and annealed coating. The property improvements are due to the formation of denser structure and oxideTiO 2 films.

This study investigated the photochemical changes of cerium oxide (CeO2) with the contribution of rare earth ions. Lanthanum (La) and Dysprosium (Dy) were added to the CeO2 crystal structure simultaneously via citric acid sol-gel synthesis. Following synthesis, the sintering temperatures were chosen as 800 and 1000 degrees C. Results of X-ray diffraction (XRD) analysis showed that the doped and undoped CeO2 compounds exhibited a cubic phase. The surface morphology of the samples was examined by scanning electron microscopy (SEM). The particle sizes varied in the range of 90-150 nm and the composite elements were observed to maintain the stoichiometric ratio. Compound impurity control was performed using energy dispersive X-ray (EDX). Lattice changes in the compounds were revealed via Raman spectroscopy, which indicated that the La and Dy had caused changes in the CeO2 symmetry. The photocatalytic behavior of the compounds was investigated using methylene blue degradation. Optical band gaps were calculated and the La and Dy were found to have narrow band spacing. The band gap of the Ce0.85La0.10Dy0.05O2 compound sintered at 1000 degrees C was 1.63 eV, the rate constant was 9.4 * 10(-3) min(,)(-1) and the degradation efficiency at 100 min was calculated as 60 %. The photoluminescence spectra exhibited four bands centered at 435, 532, 565, and 610 nm. The emission band at 565 nm was attributed to the transition from the F-4(9/2) to the (6)H(13/2)state, whereas the emission bands peaking at 435 nm, 532 nm, and 610 nm can be explained by the intrinsic luminescence of the host lattice.

Synthesis of the tricyclic 1,3-dithiole-2-thione-derived 1,4-dihydro-1,4-diphosphinine is presented using a base-induced ring formation protocol and chloro(diethylamino)(1,3-dithiole-2-thion-4-yl)phosphane as the starting point. P-oxidation reactions of dihydrodiphosphinine by chalcogens led to bis(P-oxide), bis(P-sulfide), or bis(P-selenide), respectively; all tricyclic compounds were obtained as cis/trans mixtures. 1,4-Dihydro-1,4-diphosphinine was converted into 1,4-dichloro-1,4-dihydro-1,4-diphosphinine. This compound is almost insoluble in organic solvents, furnished selectively the trans-bis(amino) derivative upon a 2-fold P-substitution reaction with the weak nucleophile potassium bis(trimethylsilyl)amide, and reacted also with alcohols ROH (R = nBu, iPr, tBu) to give cis/trans mixtures of the corresponding bis(alkoxy) derivatives. Furthermore, the dichloro derivative could be reduced to a 1,4-diphosphinine using PnBu3, but, unfortunately, the stubbornly insoluble product could be neither purified nor crystallized. Despite this, we achieved a thermal [4 + 2] cycloaddition reaction of this first CPS-ternary compound with diethylacetylene dicarboxylate to obtain the corresponding diphosphabarrelene, thus providing indirect evidence for the aromatic tricyclic diphosphinine. Detailed density functional theory studies on the formation of 1,4-diphosphinine provided insights into formation pathways as well as NMR, IR, and UV/vis data.

Zinc magnesium oxide is a ternary compound wide bandgap semiconductor. Incorporation of Mg into ZnO helps in increasing the of p-type conductivity by affecting the background n-type nature of ZnO. This is possible because Mg incorporation in ZnO elevates the conduction band edge which in turn increases the distance between the shallow donor level and conduction band minima, resulting increase of activation energy for background donor. In this work, we report Spin-on Dopant technique to dope phosphorus in Zn0.85Mg0.15O lattice. The undoped ZnMgO thin film (sample A) was deposited using RF sputtering. The SOD sample (sample B) was prepared using P509 spin on dopant and kept approximate 1cm above ZnMgO film at 600°C for four hours. The doped sample was annealed at temperature 700°C (sample C) in oxygen ambient to see the high temperature annealing effect on doping. In studies of high-resolution x-ray diffraction, a dominant (002) peak was observed in sample A, B, and C at 34.173°, 34.624°, and 34.638° respectively. The shifting of (002) peak at higher angle for doped samples indicates the phosphorus doping in film. The XPS spectra of phosphorus 2p peak are appears at ~134 eV indicates the presence of P atoms as P-O bonds in ZnMgO lattice. The Donor-Acceptor pair (DAP) transition peak around 3.473eV and free Acceptor (AX°) peak around 3.588eV were found in photoluminescence spectra of sample B revels the phosphorus doping in ZnMgO.

Langasite crystals (LGS) are known for their exceptional piezoelectric properties at high temperatures up to 1000 °C and more. In this respect, many studies have been conducted in order to achieve surface acoustic wave (SAW) sensors based on LGS crystals dedicated to high-temperature operations. Operating temperatures of more than 1000 °C and 600 °C for wired and wireless sensors, respectively, have been reached. These outstanding performances have been obtained under an air atmosphere since LGS crystals are not stable in high-temperature conditions under a low-oxygen atmosphere due to their oxide nature. However, if the stability of bulk LGS crystals under a high-temperature air atmosphere is well established, the surface deterioration under such conditions has been hardly investigated, as most of the papers dedicated to LGS-based SAW sensors are essentially focused on the development of thin film electrodes that are able to withstand very elevated temperatures to be combined with LGS crystals. Yet, any surface modification of the substrate can dramatically change the performance of SAW sensors. Consequently, the aim of this paper is to study the stability of the LGS surface under a high-temperature air environment. To do so, LGS substrates have been annealed in an air atmosphere at temperatures between 800 and 1200 °C and for durations between one week and one month. The morphology, microstructure, and chemical composition of the LGS surface was examined before and after annealing treatments by numerous and complementary methods, while the surface acoustic properties have been probed by SAW measurements. These investigations reveal that depending on both the temperature and the annealing duration, many defects with a corolla-like shape appear at the surface of LGS crystals in high-temperature prolonged exposure in an air atmosphere. These defects are related to the formation of a new phase, likely an oxiapatite ternary compound, the chemical formula of which is La14GaxSi9−xO39−x/2. These defects are located on the surface and penetrate into the depth of the sample by no more than 1–2 microns. However, SAW measurements show that the surface acoustic properties are modified by the high-temperature exposure at a larger deepness of at least several tens of microns. These perturbations of the LGS surface acoustic properties could induce, in the case of LGS-based SAW sensors operating in the 434 MHz ISM band, temperature measurement errors around 10 °C.

This work focuses on the preparation and structural characterization of the semiconductor Cu3In5Se9, an important member of ordered vacancy compounds family, belonging to the semiconductor system I3-III5--VI9, where denotes the cation vacancy which is included in the formula to maintain the same number of cations and anions sites. This material was synthesized by the Bridgman-Stockbarger technique, and its structure was refined from powder X-ray diffraction data using the Rietveld method. Cu3In5Se9 crystallizes with tetragonal symmetry in the space group P2c (Nº 112), with a = 5.7657(1) Å, c = 11.5353(4) Å, V = 383.47(2) Å3. This ternary compound consists of a three-dimensional arrangement of distorted CuSe4 and InSe4 tetrahedral connected by common faces. In this structure, each Se atom is coordinated by four cations located at the corners of a slightly distorted tetrahedron, and each cation is tetrahedrally bonded to four anions. Cu3In5Se9 is related to the p-type CuInSe2 and n-type CuIn3Se5 semiconductor compounds, which are being used in the preparation of high-efficiency solar cells. DO: http://dx.doi.org/10.17807/orbital.v13i3.1560

CuSbSe2 is emerging as an alternative absorber for thin-film photovoltaics owing to its intrinsic p-type conductivity, proper band gap (~ 1.1 eV), high-absorption coefficient (> 104 cm−1) and low cost. Moreover, it is nontoxic and its compositional elements (Cu, Se and Sb) are abundant in the crust of earth. In the present work, Sb2Se3/Cu multilayers were deposited by pulsed laser deposition (PLD) followed by magnetron sputtering (MS). After that, the as-prepared multilayers were annealed in-suit in the MS chamber at different temperatures and times to obtain high-quality CuSbSe2 ternary compound. Five intermetallic compounds were generated in this process, including CuSbSe2, Sb2Se3, CuSe2, Cu2Se and Cu3SbSe3. Besides, it was found out that most CuSbSe2 ternary compound was generated when the as-prepared multilayers were annealed at 420 °C for 10 min. The crystallite size of CuSbSe2 phase increased with elevating annealing temperature, while more holes and gaps occurred when the annealing temperature exceeded 420 °C. The results of energy-dispersive spectrometer indicated the film was highly developed with nearly stoichiometric atomic ratio of 27.91:22.72:49.37 (Cu:Sb:Se). The electrical measurement results revealed the semiconducting nature of the film and gave the conductivity activation energy of 0.26 eV, 0.08 eV and 0.13 eV, respectively. The direct band gap of the annealed film was revealed as 1.13 eV, which fulfilled the Shockley–Queisser requirements for the efficient harvesting of the solar spectrum.

Due to the resource shortage of indium, the application of 10 wt%- tin doped indium oxide (10 wt%- ITO) with 74.4 wt% of indium is restricted in the field of flat panel display. A new ternary compound TCO material with 53.8 wt% of indium (35 wt%- ITO) was prepared by In2O3-35 wt% SnO2 powders, whose microstructure and properties were studied in comparison to 10 wt%- ITO. The research findings show that: (1) The phase composition of 35 wt%- ITO target is mainly In4Sn3O12 and In2SnO5, without In2O3: Sn phase for 10 wt%- ITO; (2) When films possess the strong crystalline structure, the photoelectric properties of 35 wt%- ITO films are superior to 10 wt%- ITO. In addition, the crystalline structure of 35 wt%- ITO films could be changed from In4Sn3O12 + amorphous to In4Sn3O12 + In2O3 by annealing, but for 10 wt%- ITO, only the crystallinity is changed.

In this study, we present a quantitative analysis of the electrical properties of a series of bottom- gate top-contact n-channel transparent thin film transistors (TFTs) based on zinc indium tin oxide (Zn-In-SnO) ternary compound with various ZnO content. In addition, the effect of annealing on the TFTs electrical properties was examined theoretically and experimentally. The obtained results revealed that the thermal annealing of fabricated devices in air atmosphere at 300 °C has enhanced their performances; this behavior is well observed for all devices fabricated with different composition of Zn-In-SnO. TFTs having the lowest Zn content of 17.1% and annealed 300°C showed the high electrical performances in term of drain current, saturation mobility, threshold voltage. For the total resistance modeling of the fabricated devices with various content of ZnO and that annealed 300 °C, grain boundary model based on Meyer–Neldel rule was applied. The obtained results revealed that the total resistance was increased with increasing ZnO content. Furthermore, an analytical model has been refined in order to reproduce the current-voltage relationships of the fabricated TFTs using the overall resistance obtained from the NMR–GBT model. The calculated results are in good agreement with the experimental measurements of all fabricated devices. The obtained performance of TFTs based on zinc indium tin oxide with low content of ZnO and annealed will be promising for application in the future backplane of flat panel displays.

The isothermal section of the Al-Si-Ti ternary system at 550 °C has been determined using scanning electron microscopy, energy dispersive spectroscopy, and x-ray diffraction. Results show that there are 12 three-phase equilibrium regions in the isothermal section of the system. The maximum solubility of Si in Al3Ti is 16.4%, and the solubility of Al and Ti in Si is small. There exists only one ternary compound in the isothermal section with a composition of Al7.1-13.9Ti33.5-34.2Si51.9-59.1.

The influences of Nb-containing oxides and ternary compound in hydrogen sorption performance were investigated. As faster desorption kinetic and lower activation energy were reported by addition of a ternary compound catalyst such as K2NiF6, the influence of KNbO3 on hydrogen storage properties of MgH2 has been investigated for the first time. The MgH2 - KNbO3 composite desorbed 3.9 wt% of hydrogen within 10 min, while MgH2 and MgH2-Nb₂O₅ composites desorbed 0.66 wt% and 3.2 wt% respectively under similar condition. For MgH2 with other Nb-contained catalysts such as Nb, NbO and Nb₂O3, the desorption rate was almost the same as the one registered for as-milled MgH2. The analysis of differential scanning calorimetry (DSC) showed that MgH2-KNbO3 composite started to release hydrogen at ∼335 °C which is 50 °C lower compared to as-milled MgH2 without any additives. The activation energy for the hydrogen desorption was estimated to be about 104 ± 6.8 kJ mol−1 for this material, while for the as-milled MgH2 was about 165 ± 2.0 kJ mol−1. It is believed that Nb-ternary oxide catalyst (KNbO3) showed a good catalytic effect and enhance the sorption kinetics of MgH2.

The fission product strontium (Sr), after generation in the reactor due to fission of 233U, might exist as SrF2 in the molten fluoride medium of molten salt reactor (MSR) using fluoride carrier salts. The high temperature interactions between the strontium fluoride (SrF2) with the fertile fuel component and thorium fluoride (ThF4) leads to form single ternary compound SrThF6(s). The Gibbs energy of formation is the driving force for formation of any compound. In the present study, standard molar Gibbs energy of formation SrThF6(s) has been determined using an e.m.f. technique using CaF2(s) as solid electrolyte. Using the experimental thermodynamic data, to study the stability domain of SrThF6(s), the chemical potential diagram of Sr-Th-F-O system and ternary phase diagram of Sr-Th-F2 system have been calculated.

We report here on the discovery of the superconductivity of a new ternary compound LaRh2Ga2, which possesses a CaBe2Ge2-type structure. Electrical resistivity and magnetic susceptibility measurements reveal that LaRh2Ga2 undergoes a superconducting transition at 3.7 K and exhibits type-II superconductivity. The T-linear behavior of the upper critical field is likely induced by the two-gap superconducting state because of its structural features (i.e., its noncentrosymmetric structure). A transition at Tc of specific heat suggested that the LaRh2Ga2 is a weak electron-phonon-mediated superconductor. Comparison with a related superconductor demonstrates that there is an important factor other than electron-phonon coupling strength that induces higher Tc in the LaTM2Ga2 system with a noncentrosymmetric CaBe2Ge2-type structure.

Single crystals of a novel Na-Pt-Si ternary compound, Na3Pt10Si5, were synthesized by heating the constituent elements at 1423 K. It crystallizes in a non-centrosymmetric trigonal structure of space group R32 (Z = 3) with lattice constants of a = 10.1536(3) A and c = 10.1539(3) A at 300 K. The structure consists of a three-dimensional framework made of Pt and Si atoms, and the Na atoms are contained in the tunnels of the framework. The large magnitude and the temperature dependence of the atomic displacement parameter of the Na site reveal a large thermal vibration indicative of a "rattling" motion of Na atoms in the oversized tunnel. The electronic structure calculations explain the observed metallic properties on the basis of the covalent bonds between the Pt and Si atoms in the framework and the ionic bonding of the Na atoms to the framework. A type II superconductivity with a transition temperature of 2.9 K and an upper critical field of 2.5 kOe are observed for a polycrystalline sintered bulk sample of Na3Pt10Si5 prepared by heating at 1353 K in Na vapor. Heat capacity measurements reveal a strong coupling superconductivity that is probably caused by an electron-phonon interaction enhanced by the rattling motion of the Na atoms.

The new ordered vacancy compound Ag 3 In 5 Te 9 was synthesized by the melt and annealing technique and its structure was refined from X-ray powder diffraction pattern using the Rietveld method. The title compound crystallizes in the tetragonal space group P 2 c (No 112), with a = 6.3453(2) A, c = 12.5754(7) A, V = 506.32(4) A 3 . The refinement of 23 instrumental and structural parameters led to R p = 5.4%, R wp = 5.8%, R exp = 5.1 %, S = 1.1. This ternary compound is isostructural with Cu 3 In 5 Te 9 and have a defect adamantane structure.

The single crystals of BaIn2Te4 have been synthesized at 1173 K using the sealed tube solid-state method. The polycrystalline sample of the compound was also synthesized by stoichiometric reaction of elements with intermittent grinding and annealing at 1123 K. The crystal structure of BaIn2Te4 has been established by single crystal X-ray diffraction study at 298(2) K. It crystallizes in space group D 2 h 20 −Cccm of the orthorhombic crystal system with unit cell dimensions of a = 7.1417(14) A, b = 12.034(2) A, and c = 12.107(2) A with four formula units. The structure of BaIn2Te4 is related to the tetragonal binary TlSe structure (space group: I4/mcm). The crystal structure of BaIn2Te4 features one-dimensional chains of 1 ∞ [In2Te42−] that are separated by filling of Ba atoms. Indium atoms in these chains are surrounded by four Te atoms that form distorted tetrahedron geometry around In atoms. This compound does not show any homoatomic bonding and is having a closed shell electronic configuration. Thus, it can be easily charge balanced as Ba2+(In3+)2(Te2−)4. The phase purity of the polycrystalline BaIn2Te4 sample was established by the powder X-ray diffraction study. The direct band gap of 1.36(2) eV was estimated from the optical absorption study at room temperature. This ternary compound is an n-type semiconductor as suggested by the negative sign of the Seebeck coefficients (S). The absolute value of S was found to be decreasing on heating the polycrystalline BaIn2Te4 sample. The temperature-dependent resistivity study confirmed the semiconducting nature of the BaIn2Te4 sample. The thermal conductivity (κtot) values of polycrystalline BaIn2Te4 were found to be extremely low and were decreasing with raising the temperature with the lowest value of 0.30 Wm−1K−1 at 965 K. Hence, BaIn2Te4 and its analogs with related structures could be promising materials for thermoelectric applications by further optimization of carrier concentrations to improve electrical transport properties.

With assistance of Mo interlayer, joining of Cf/SiC composite to GH783 superalloy was carried out using NiPdPtAu-Cr filler alloy. Under the brazing condition of 1200 °C for 10 min, the maximum joint strength of 98.5 MPa at room temperature was achieved when the thickness of Mo interlayer was 0.5 mm. Furthermore, the corresponding joint strength tested at 800 °C and 900 °C was even elevated to 123.8 MPa and 133.0 MPa, respectively. On one hand, the good high-temperature joint strength was mainly attributed to the formation of the refractory Mo-Ni-Si ternary compound within the joint. On the other hand, the residual Mo interlayer as a hard buffer, can release the residual thermal stresses within the dissimilar joint. The Cf/SiC-Mo bonding interface was still the weak link over the whole joint, and the cracks propagated throughout the whole reaction zone between the Cf/SiC composite and the Mo interlayer.

International audience; The structure, the chemistry, and the magnetic properties of MnCoGe thin films elaborated by reactive diffusion were investigated. In situ X-ray diffraction (XRD) was used to study phase formation during thin film reaction. MnCo, MnGe, and CoGe binary systems were studied before investigating phase formation during Mn-Ge-Co ternary system reaction. Three pure layers of Mn, Ge, and Co were successively deposited by magnetron sputtering on SiO2 to form a 200 nm-thick Co/Ge/Mn stack, and annealed. Six phases were observed during reaction, first following the sequential phase formation observed for the binary systems at the two Mn/Ge and Ge/Co interfaces, and ending with the formation of a single ternary compound MnCoGe at 673 K. The structure and the composition of the MnCoGe films were characterized using XRD, atomic force microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy. The magnetic properties of the films were studied using superconducting quantum interference device (SQUID) and ferromagnetic resonance (FMR) measurements. The obtained MnCoGe thin films are polycrystalline with the stoichiometric composition Mn:Co:Ge(1/3:1/3:1/3), and show high porosity. They are made of grains exhibiting both the Ni2In-type hexagonal structure and the TiNiSi-type orthorhombic structure.

The effect of calcium content on the microstructure and subsequent mechanical properties of ZK60 magnesium alloy in the cast and extruded conditions were precisely studied. Alloys containing 0, 0.1, 0.5, 1, and 2% (wt%) Ca were cast, were homogenized, and then were extruded by an extrusion ratio of 12:1. The base alloy (free of Ca) exhibited partially divorced-eutectic morphology, whereas the Ca containing alloys displayed lamellar or rod-like shaped morphologies. Along with the totally different morphology, the addition of Ca to the base alloy also gave rise to a gradual replacement of the Mg–Zn binary compound with the Ca2Mg6Zn3 ternary compound. It is realized that the Ca-containing intermetallic compound considerably restricted the grain growth during solidification, and the cast structure was efficaciously refined. Applying the hot extrusion procedure, as an effective thermomechanical processing route, not only modified the cast microstructure by decreasing grain size, breaking the eutectic network and changing the size and morphology of Ca-rich intermetallic phases, but also significantly mitigated the population of casting defects. The higher capability of Ca-containing Mg alloys in grain refinement in extruded samples was attributed to the activation of the particle-stimulated nucleation mechanism, especially adjacent to the large ternary Mg–Zn–Ca phases. Additionally, the room temperature tensile properties and corresponding fracture surfaces were also assessed and correlated with the microstructural evolutions.

The 600 and 800 °C isothermal sections of the Al-Sb-Cr ternary system were studied by scanning electron microscopy, energy dispersive x-ray spectroscopy, and x-ray diffraction. No ternary compound was found in this system at either 600 or 800 °C. AlSb can equilibrate with all phases in both the 600 and 800 °C isothermal sections except Cr. Ten three-phase regions were clearly identified in the Al-Sb-Cr ternary system at 600 °C and seven three-phase regions were confirmed in the 800 °C isothermal section.

The Al–Cr–Dy system has been investigated over the whole composition by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), scanning electron microscope and energy dispersion spectroscopy (SEM-EDS). The existence of known compounds Al8Cr4Dy and Al43Cr4Dy6 has been confirmed at 773 K. Binary compounds Al11Cr2 and Al17Dy2 do not exist in this isothermal section. The structure of the CeCr2Al20-type ternary compound Al20Cr2Dy has been determined with Rietveld refinement. This compound belongs to space group Fd 3 ¯ m and lattice parameter a = 1.44524 nm. The results shows that there are 16 single-phase regions, 31 two-phase regions and 16 three-phase regions in the studied isothermal section. The maximum solubility of Cr in AlDy2 and Al2Dy are confirmed to be 1.8 and 2.1 at. %, respectively. No significant solid solubility can be found in the other binary compounds of the Al–Cr–Dy ternary system at 773 K.

The isothermal section of the Gd-Ni-In system at T = 870 K was constructed by means of X-ray powder diffraction and EDX analyses. Thirteen ternary compounds, namely GdNi9In2 (YNi9In2 type), Gd1−1.22Ni4In1-0.78 (MgCu4Sn type), GdNiIn2 (MgCuAl2 type), Gd4Ni11In20 (U4Ni11Ga20 type), GdNi1.0-0.7In1.0-1.3 (ZrNiAl type), Gd2Ni2In (Mn2AlB2 type), Gd2Ni1.78In (Mo2FeB2 type), Gd11Ni4In9 (Nd11Pd4In9 type), Gd12Ni6In (Sm12Ni6In type), Gd6Ni2.39In0.61 (Ho6Co2Ga type), Gd14Ni3.29In2.71 (Lu14Co3In3 type), Gd3Ni0.05In0.95 (AuCu3 type) and ~Gd6Ni2In exist in the Gd-Ni-In system at this temperature. The substitution of Ni for In was observed for GdNi1.0-0.7In1.0-1.3 and of In for Gd for Gd1-1.22Ni4In1-0.78. Besides, Gd can enter the structure of NiIn (CoSn type) leading to a solid solution Gd0-0.14NiIn1-0.98.

The phase equilibria of the Co-Ti-Ru ternary system at 1000, 1100, and 1200 °C were studied using the electron probe microanalyzer and x-ray diffraction. The results show that: (1) no ternary compound exists in the isothermal sections from 1000 to 1200 °C; (2) the phases of CoTi and TiRu form the continuous solid solution phase (Co,Ru)Ti; (3) the solubility of Ru in the Co3Ti phase is less than 5 at.% at isothermal sections 1000-1100 °C. These experimental results will provide useful information for the foundation for alloy design and the supplement for thermodynamic databases.

The phase equilibria of Gd-Fe-Cr system were investigated at 800 °C by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The isothermal section of the phase diagram consisted of eight single-phase regions, eight two-phase regions and seven three-phase regions. The binary compounds GdFe2, GdFe3, Gd2Fe17, σ(FeCr) and the ternary compound GdFe10Cr2 were confirmed. Conversely, the binary compound Gd6Fe23 was unstable at the level of 800 °C. The maximum solid solubilities of Cr in GdFe2 and Gd2Fe17 were about 11.7 and 13.2 at. % Cr respectively. The compound GdFe12−xCrx with the ThMn12-type structure (space group I 4 / m m m ) has a broad solubility ranging from 15.4 to 23.1 at. % Cr.

Despite the improvements seen in efficiency of GaAs cells over the years, there remains room for improvement for it to approach the theoretical single junction limit posited by Shockley and Quiesser decades ago. One of the more pursued options is the growth of quantum wells within the structure of GaAs to enhance its photon absorption below its bandgap. Multiple Quantum Wells (MQW) have been an ongoing topic of research and discussion for the scientific community with structures like InGaAs/GaAs and InGaP/GaAs quantum wells producing promising results that could potentially improve overall energy conversion. Here, we used WEIN2K, a commercial density functional theory package, to study the ternary compound Ga1-xTlxAs and determine its electronic properties. Using these results combined with experimental confirmation we extend these properties to simulate its application to form a MQW GaAs/ Ga1-xTlxAs solar cell. Ga1-xTlxAs is a tunable ternary compound, with its bandgap being strongly dependent on the concentration of Tl present. Concentrations of Tl as low as 7% can reduce the bandgap of Ga1-xTlxAs to roughly 1.30 eV from GaAs’s 1.45 eV at room temperature with as little as a 1.7% increase in lattice constant. The change in bandgap, accompanied by the relatively small change in lattice constant makes Ga1-xTlxAs a strong candidate for a MQW cell with little to no strain balancing required within the structure to minimize unwanted defects that impede charge collection within the device. Our GaAs photodiode with TlGaAs MQWs shows an expanded absorption band and improved conversion efficiency over the standard GaAs photovoltaic cell with dilute concentrations of Tl incorporated into the compound.