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Herein, we explore a general Cu2-x S nanocube template-assisted and reverse cation exchange-mediated growth strategy for fabricating hollow multinary metal sulfide. Unlike the traditional cation exchange method controlled by the metal sulfide constant, the introduction of tri-n-butylphosphine (TBP) can reverse cation exchange to give a series of hollow metal sulfides. A variety of hollow multinary metal sulfide cubic nanostructures has been demonstrated while preserving anisotropic shapes to the as-synthesized templates, including binary compounds (CdS, ZnS, Ag2 S, PbS, SnS), ternary compound (CuInS2 , Znx Cd1-x S), and quaternary compound (single-atom platinum anchored Znx Cd1-x S; Znx Cd1-x S-Pt1 ). Experimental and density functional theory (DFT) calculations show that the hollow metal sulfide semiconductors obtained could significantly improve the separation and migration of photogenerated electron-hole pairs. Owing to the efficient charge transfer, the Znx Cd1-x S-Pt1 exhibited outstanding photocatalytic performance of CO2 to CO, with the highest CO generation rate of 75.31 μmol h-1 .

Simultaneously improving energy efficiency (EE) and material stability in electrochemical CO2 conversion remains an unsolved challenge. Among a series of ternary Sn-Ti-O electrocatalysts, 3D ordered mesoporous (3DOM) Sn0.3 Ti0.7 O2 achieves a trade-off between active-site exposure and structural stability, demonstrating up to 71.5 % half-cell EE over 200 hours, and a 94.5 % Faradaic efficiency for CO at an overpotential as low as 430 mV. DFT and X-ray absorption fine structure analyses reveal an electron density reconfiguration in the Sn-Ti-O system. A downshift of the orbital band center of Sn and a charge depletion of Ti collectively facilitate the dissociative adsorption of the desired intermediate COOH* for CO formation. It is also beneficial in maintaining a local alkaline environment to suppress H2 and formate formation, and in stabilizing oxygen atoms to prolong durability. These findings provide a new strategy in materials design for efficient CO2 conversion and beyond.

First principles calculations by using of projected augmented plane-wave method have been performed to investigate the structural, elastic and electronic properties of MgB2C2 under different pressures. The results indicate that the ternary compound of MgB2C2 remains mechanically stable under pressure ranging from 0 to 50 GPa. Elastic analysis is performed and it is found that MgB2C2 always shows obvious intrinsic brittleness under pressure, although an increasing trend of the ductility both from BH/GH and vH with increasing pressure. (100), (010) and (1-10) planes show strong anisotropy and the degree of anisotropy decreases with increasing pressure, in the meantime, it is interesting to find that the degree of anisotropy is reduced in order of planes (1-10)-(100)-(010) under the same pressure.

In this study, Bi2O3-based (Er2O3)x(Gd2O3)y(Bi2O3)1-x-y ternary compound powders were synthesized with different stoichiometric ratios by the solid-state reaction method at different annealing treatment. Crystal structure characterization was investigated via X-ray powder diffraction method in order to determine the fcc-cubic phases powders. Microstructure properties of pellet samples obtained from scanning electron microscopy. Also, thermal properties and porosity were investigated via differential thermal analysis and Brunauer-Emmett-Teller analysis. δ-Phase structure was provided at all ternary samples at 800°C heat treatment temperature. The relationship between lattice parameters and total dopant rate was analyzed. As the amount of dopant rate increased, lattice parameters were increased. In conclusion, a correlation between the ionic radius of the dopant cations and lattice parameters was revealed.

We report the first solvate structure of the silicide anion Si44–, which provides circumstantial evidence of the stability of the highly charged anion in liquid ammonia solutions. The solvate Rb1.2K2.8Si4·7NH3 crystallized from a mixture of the ternary compound K6Rb6Si17 with the transition metal complex [(C6H5)3P]2Ni(CO)2 [bis(triphenylphosphine)dicarbonylnickel] in the presence of the chelating agents 18-crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane) and [2.2.2]cryptand (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane) in liquid ammonia. Single X-ray diffraction analysis confirms the presence of the Si44– anion in the crystal structure of Rb1.2K2.8Si4·7NH3, which represents the first solvate compound of the naked tetrasilicide tetraanion. All five crystallographically independent cation positions show mixed occupancy by Rb+ and K+.

Nowadays, the attention of researchers is focused on the large family of chalcogenides that poses very unique and interesting properties. One of them is the teallite – PbSnS2, almost unrevealed ternary compound, promising thermoelectric material. In this work, we present first detailed Raman studies of PbSnS2, including the polarization-dependent and temperature-dependent measurements (80–400 K range). The strong effect of polarization angle and temperature on the Raman spectra was observed. The polarization studies allowed to assign symmetry of observed modes. The temperature evolutions of the Raman spectra were explained by optical phonon decay into two or three acoustic phonons with equal energies. The extracted first-order temperature coefficients are among the largest reported so far for layered materials. Our results might be helpful in understanding the anisotropic optical, thermal and electrical properties of PbSnS2. Copyright © 2016 John Wiley & Sons, Ltd.

Single crystals of Ta7Cu10Ga34 were grown from the elements in a Cu/Ga melt. Ta7Cu10Ga34 represents the first ternary compound of the system Ta/Cu/Ga. The crystal structure (Cmmm, oC102, Z = 2, a = 23.803(1), b = 12.2087(4), c = 5.7487(2) A, 1291 refl. 78 parameters, R1 = 0.037, wR2 = 0.070). The crystal structure is characterized by rods of pentagonal prisms MGa10, which are alternatingly occupied by Ta and Cu. Four of these rods are connected to columns running in direction (001). These columns are linked by cubic units TaGa8, CuGa8, and GaGa8. According to the characteristic structural elements and the size of the unit cell Ta7Cu10Ga34 represents a 8 × 4 × 2 super structure of CsCl or bcc. With respect to the underlying CsCl structure the formula can be written as [Ta7Cu10Ga2□13]Ga32, i.e. a cubic primitive packing of 32 Ga atoms with Ta, Cu, and Ga in cubic voids and 13 vacancies. The pentagonal-prismatic coordination of Ta and Cu can formally be obtained from the cubic primitive packing of Ga atoms by a 45° rotation of a part of the Ga8 cubes. There is a close similarity to the binary compounds Ta8Ga41 and Ta2–xGa5+x. The first one is also related to a CsCl-like structure, the latter one contains rods of pentagonal prisms, which form the same columns. There are also relations to the ternaries V2Cu3Ga8 and V11Cu9Ga46, whose cubic structures are more or less complex variants of CsCl.

Pressureless sintering is a well-established powder metallurgical route for processing and consolidation of mixed materials. Especially materials exhibiting a high melting point could be densified without tool abrasion by this sintering technique. As the sintering temperatures are often higher compared to pressure-assisted techniques care must be taken by means of grain growth. In our studies we used a ternary compound mixture to obtain Mo-based alloys. Consolidation applying pressure-assisted methods (hot pressing, spark plasma sintering) and pressureless sintering were used, respectively. The densities reached and the microstructures obtained were compared. These Mo-Si-B alloys were processed using a nitride-powder-based route offering lower impurity contents due to short processing times by avoiding time consuming mixing / milling steps. The sintering conditions depending on the powder particle size as well as the sample shape will be presented in detail. The composition investigated in this article offered a continuous a-Mo matrix with intermetallic islands consisting of Mo3Si and Mo5SiB2 (T2) phases. The combination of a ductile a-Mo matrix and intermetallic phases embedded within offered an enhanced mechanical behavior at room temperature compared to MoSi2 or other intermetallic alloys. Moreover, the intermetallic compounds as well as Mo are candidates for high-temperature applications. As the high-temperature behavior could be strongly influenced by the respective microstructure we present here the processing and the microstructure obtained.

Alx Ga1-x N thin-film-based piezotronic strain sensors with ultrahigh strain sensitivity are fabricated through alloying of AlN with GaN. The strain sensitivity of the ternary compound Alx Ga1-x N is higher than those of the individual binary compounds GaN and AlN. Such a high performance can be attributed to the piezoelectric constant enhancement via intercalation of Al atoms into the GaN matrix, the effect of residual strain, and a suppressed screening effect.

Presented in this work are the results concerning formation of nano-scale patterns on the surface of a ternary compound Hg1–xCdxTe (x ∼ 0.223). Modification of this ternary chalcogenide semiconductor compound was performed using the method of oblique-incidence ion bombardment with silver ions, which was followed by low-temperature treatment. The energy and dose of implanted ions were 140 keV and 4.8×1013 cm-2, respectively. Atomic force microscopy methods were used for the surface topography characterization. The structural properties of MCT-based structure was analyzed using double and triple crystal X-ray diffraction to monitor the disorder and strain of the implanted region as a function of processing conditions. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

By ab initio calculation using the ABCAP code, energy shifts of core levels and optical properties of B-incorporated AlN (AlBN) were examined through comparison with experimental spectra measured from the thin film. Good agreements of complex refractive indices, n and k, with experiment were obtained for pure AlN and pure BN. However, when B content is increased in AlBN, substantial disagreement is found between experiment and calculation that assumed either wurtzite or graphite-like structure for clarity. These results suggest that AlBN with ca. 30% is neither complete solid solution nor grain-level mixture of graphite like BN and AlN. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The ternary compound Cu2SnS3 (CTS) is composed of elements that are low in cost, non-toxic, and abundant in the Earth's crust. In addition, CTS is a p-type semiconductor with a high reported absorption coefficient of more than 104 cm−1 and a band gap energy of 0.92–1.77 eV. It is, therefore, considered to be a suitable candidate for the absorber layer in thin film solar cells. In the present study, CTS thin films were produced by first depositing precursor films by co-evaporation of Cu, Sn, and S, and then annealing them. Solar cells were then fabricated using the CTS films as absorber layers, and the dependence of their photovoltaic properties on the annealing temperature was investigated. The solar cell using the CTS thin film annealed at 570 °C exhibited an open-circuit voltage of 248 mV, a short-circuit current density of 33.5 mA/cm2, a fill factor of 0.439, and a conversion efficiency of 3.66%.

Device applications involving topological insulators (TIs) will require the development of scalable methods for fabricating TI samples with sub-micron dimensions, high quality surfaces, and controlled compositions. Here we use Bi-, Se-, and Te-bearing metalorganic precursors to synthesize TIs in the form of nanowires. Single crystal nanowires can be grown with compositions ranging from Bi2Se3 to Bi2Te3, including the ternary compound Bi2Te2Se. These high quality nanostructured TI compounds are suitable platforms for on-going searches for Majorana Fermions.

Using X-ray diffraction it was established that the actual composition of the ternary compound reported as “TbAl2Ge” is close to Tb2Al3Ge3 (refined Tb2Al3.039(1)Ge3). Differential thermal analysis showed that the compound exists in a narrow temperature range from 618 to 748 °C. The crystal structure was determined from X-ray powder and single-crystal diffraction data. An initial model was constructed from CaAl2Si2- and AlB2- (or LiBaSi-) type slabs. A more detailed investigation revealed that, instead of LiBaSi-type slabs(where the small atoms form planar nets), the structure contains ScAuSi-type slabs (corrugated nets), where 1/6 of the Tb atoms have been removed in an ordered way, leading to a rhombohedral superlattice. The final structure represents a new structure type: Pearson symbol hR234–41.06, space group R3¯c, a = 7.2432(3), c = 87.998(8) A. Part of the Al atoms in the Tb-deficient ScAuSi-type slabs occupy a site that forms Al3 triangles. The structure of Tb2Al3Ge3 is thus closely related to the rhombohedral ErNi3Al9 and orthorhombic Y2Co3Ga9 structure types, which contain one-atom thick Er2Al3 (Y2Ga3) layers formed by rare-earth metal atoms and Al3 (Ga3) triangles. Compounds isotypic with Tb2Al3Ge3 were found in the systems Y-Al-Ge and Gd- Al-Ge.

A second type of cation (Mg2+, Ca2+) was introduced into BaF2 by low-temperature atomic beam deposition. The structure evolution from low-temperature (–150 °C) amorphous deposits to high-temperature (< 1000 °C) annealed crystalline phases was studied by in-situ transmission electron microscopy and X-ray diffraction. Amorphous (Ba0.5, Ca0.5)F2 crystallizes in a first step to metastable solid solution phase (fluorite-type), which then decomposes into the pure phases of CaF2 and BaF2 at higher temperature. The crystallization behavior of amorphous (BaxMg1–x)F2 is completely different. When the Mg/Ba atomic ratio is around 1:1, the mixture transforms to the ternary compound BaMgF4 at annealing, and no decomposition occurs by further heating up to 1000 °C. When the Ba concentration is below 15 % in atomic ratio (x < 0.15), the mixture forms a solid solution phase (rutile type) with the lattice expanded by +1 % compared to rutile type MgF2. The difference between the phase evolutions of the two mixture systems is discussed.

Powder samples and single crystals of the new ternary compound NbRuB were synthesized by arc-melting of the elements in a water-cooled crucible under an argon atmosphere. The samples have been characterized by X-ray diffraction and energy-dispersive X-ray spectroscopy (EDX) measurements. Furthermore, the crystallographic, electronic, and bonding characteristics have been studied by density functional theory. The title compound crystallizes with a new orthorhombic structure type in the space group Pmma (no. 51) with the lattice parameters a = 10.870(2) A, b = 3.173(1) A, and c = 6.350(2) A. The structure consists of two kinds of atomic layers: the first layer (at y = 0) contains niobium atoms and isolated boron atoms, and the second (at y = 0.5) contains ruthenium atoms and boron dumbbells. Electronic structure relaxation has confirmed the crystallographic parameters, and crystal orbital Hamilton population (COHP) bonding analysis indicates that the B–B bond is the strongest bond, but the numerous and relatively strong metal–boron and Nb–Ru bonds are responsible for the overall stability and indicate a three-dimensional bonding character in the new compound.

The function of nanometer-size quantum dots (QDs) of ternary compound semiconductors, such as InxGa1−xAs and ZnSe1−xTex, used in the fabrication of optoelectronic and photovoltaic devices can be optimized by precise tuning of their electronic band gap through control of the QD composition (x) and diameter. Results on compositional distributions in ternary QDs and how they affect the QDs' electronic band gap are reported. A hierarchical modeling approach is followed that combines first-principles density functional theory calculations and classical Monte Carlo simulations with a continuum model of species transport in spherical nanocrystals. In certain cases, the model predicts the formation of core/shell-like structures with shell regions rich in the surface segregating species. A systematic parametric analysis generates a database of transport properties, which can be used to design post-growth thermal annealing processes that enable the development of thermodynamically stable QDs with optimal electronic properties grown through simple one-step colloidal synthesis techniques. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3223–3236, 2013

The ternary compound semiconductor Cu2SnS3 (CTS) is formed from non-toxic materials that are abundant in Earth's crust and other low-cost elements. CTS has also been reported to a band gap energy range of 0.93–1.77 eV and an absorption coefficient of 1.0×104 cm–1. Consequently, CTS is a potential material for the p-type absorber layer of thin film solar cells. In this study, we examined the dependence of the optical, electrical and photovoltaic properties of CTS thin films on the Cu/Sn composition ratio. CTS thin films were fabricated by sulfurizing evaporated Cu-Sn precursors with different Cu/Sn composition ratios at 560 °C for 2 h in a N2 atmosphere and sulfur vapor. The Cu/Sn composition ratios of the sulfurized films were determined to be 1.6–2.5 by X-ray fluorescence. The solar cell comprising a CTS thin film with a Cu/Sn composition ratio of 1.77 exhibited the best performance among the cells examined, an open-circuit voltage of 242 mV, a short-circuit current density of 28.9 mA/cm2, a fill factor of 41.7% and a conversion efficiency of 2.92% were obtained. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The isothermal section of the Fe-Pd-Nd ternary system at 773 K was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and energy dispersion spectroscopy (EDS) techniques. It is found that the isothermal section consists of 15 single-phase regions, 28 two-phase regions and 14 three-phase regions. The highest solubilities of Nd in FePd and FePd3, Pd in Fe17Nd2 and Fe17Nd5 and Fe in Pd5Nd, Pd2Nd, Pd3Nd2, Pd4Nd3 and PdNd are all less than 1 at.%. Whereas the maximum solubilities of Fe in Pd3Nd and Pd3Nd7 are approximately confirmed to be 1.0 and 4.1 at.% Fe, respectively. In the present work, a new ternary compound Nd6Fe13Pd with Pr6Fe13Ag structure, space group I4/mcm and lattice parameters a = 0.8076(2) and c = 2.2373(7) nm is observed.

A new ternary compound with composition Cu5Sn2Te7 has been synthesized using the stoichiometric reaction of Cu, Sn, and Te. The compound crystallizes in C2 space group with unit cell parameters of a = 13.549(2) A, b = 6.0521(11) A, c = 9.568(2) A, and β = 98.121(2)°. Cu5Sn2Te7 is a superstructure of sphalerite and exhibits tetrahedral coordination of Cu, Sn, and Te atoms, containing a unique adamantane-like arrangement. The compound is formally mixed valent with a high electrical conductivity of 9.8 × 105 S m–1 at 300 K and exhibits metallic behavior having p-type charge carriers as indicated from the positive Seebeck coefficient. Hall effect measurements further confirm holes as charge carriers with a carrier density of 1.39 × 1021 cm–3 and Hall mobility of 4.5 cm2 V–1 s–1 at 300 K. The electronic band structure calculations indicate the presence of a finite density of states around the Fermi level and agree well with the p-type metallic conductivity. Band structure analysis suggests that the effective m...

The subsolidus phase relations of the BaO–Y2O3–MnO2 system have been investigated in air. There are eight binary compounds, a new ternary compound and 11 three-phase regions in this system. The ternary compound with the BaO:YO1.5:MnO2 molar ratio of 8:2:5 was indexed by a rhombohedral lattice with a = 5.7929 (6) and c = 28.586 (4) A. The synthesized compounds were determined to be stoichiometric except for the Ba1−xYxMnO3 phase (x ≤ 0.01).

The melt-quenching method was used to prepare two groups of samples using CdO and V2O5 as starting materials. Taking into account that a crystalline-amorphous phase transition would be expected for the CdO–V2O5 system, a first batch was prepared varying the proportions of CdO and V2O5 in the intervals 60–95 and 40–5 wt%, respectively. With the aim of investigating the effect of erbium in the phase transition and crystalline quality of the first group of samples, a second batch was fabricated with the same proportions of CdO and V2O5, with the addition of 5 wt% of Er(NO3)5H2O as source of Er3+ ions. It was found that crystalline or amorphous samples could be obtained depending on the relative concentrations of CdO and V2O5, and that the borderline between amorphous and crystalline samples was affected by the incorporation of Er. From X-ray diffraction, it was possible to identify the formation of the ternary compound Cd2V2O7 in the crystalline cases. The Raman and infrared bands in these samples were in agreement with the lattice modes of Cd2V2O7. Additionally, an improvement in the crystalline quality of Cd2V2O7 was obtained for the Er-doped samples. The effect of the local environment around the Er3+ ions on the room temperature photoluminescence was also investigated for the amorphous and crystalline samples.

Ternary perovskite compound films of Pb(Mn,Nb)O3-PbZrO3-PbTiO3 (PMnN/PZ/PT) with different doping ratios of PMnN into PZT(52/48) matrix are deposited on SrRuO3 buffered Si substrates by a radio frequency magnetron sputtering system. It is found that the crystal structures, orientations, lattice constants of the ternary compound films are strongly dependent on the doping ratios of PMnN as the doping ratios are changed from 6 to 30%. These sputtered films showed polycrystal structures with mixed crystal orientations of (001)/(100), (101), (111) perovskite phases. As the doping ratio of the PMnN is in the range of (5–20)%PMnN-(95–80)%PZT, the doping greatly improves the ferroelectricity and piezoelectricity. The highest values of the effective transversal piezoelective coefficient, e31,f = −16.94 C/m2, for the thin films is obtained at the doping ratio of 20%PMnN, which is much larger than that of the similar PZT-based materials and benefit to make piezoelectric devices.

AlGaN/GaN heterostructure field-effect transistors were grown by metalorganic vapor phase epitaxy on Fe-doped GaN substrates with a preflow of the Mg source. We realized a low drain leakage current, 1.05 μA/mm, at V DS = 20 V and V GS = ―5 V with L GD = 3 μm. This leakage current was one order of magnitude lower than that obtained without a preflow of the Mg source. The breakdown voltage was over 250 V with L GD = 10 μm. The on resistance was estimated to be 3.6 mΩ cm 2 . No significant redistribution or memory effect of Mg was observed by secondary ion mass spectroscopy measurement.

We report on the design and fabrication of interband cascade light emitting diode (LED) device with InAs/Ga 1-x In x Sb/InAs quantum well (QW) active region. We have varied indium (In) contents in the QW region between 18 and 30% from x = 0.18 to 0.3 and found that light emission power increases with decrease of In percentage value. We observed a 200% increase in light emission power by decreasing the In content from 30 to 18%. By cooling the LED device, we observed a higher increase in light output power for higher In content devices compared to that of lower In content devices.

Four tunnel junction (TJ) designs for multijunction (MJ) solar cells under high concentration are studied to determine the peak tunnelling current and resistance change as a function of the doping concentration. These four TJ designs are: AlGaAs/AlGaAs, GaAs/GaAs, AlGaAs/InGaP and AlGaAs/GaAs. Time-dependent and time-average methods are used to experimentally characterize the entire current–voltage profile of TJ mesa structures. Experimentally calibrated numerical models are used to determine the minimum doping concentration required for each TJ design to operate within a MJ solar cell up to 2000-suns concentration. The AlGaAs/GaAs TJ design is found to require the least doping concentration to reach a resistance of

Optical properties of strain-compensated InGaN/InGaN quantum well (QW) structures using a InGaN substrate are investigated using the multiband effective mass theory. These results are compared with those of conventional InGaN/GaN QW structures using a GaN substrate. The strain-compensated QW structure shows that a smaller well thickness is needed to obtain the transition wavelength of 530 nm than the InGaN/ GaN QW structure. The spontaneous emission peak of a strain-compensated QW structure is shown to be much larger than that of a conventional QW structure. This is mainly attributed to the fact that the internal field is reduced due to the decrease in the lattice mismatch with a substrate.

We demonstrated activation annealing of Mg-doped p-type Al 0.17 Ga 0.83 N in different gases. The hole concentration of Al 0.17 Ga 0.83 N annealed in oxygen is higher than that annealed in nitrogen or air. A hole concentration of 1.3 × 10 16 cm -3 at room temperature was achieved by annealing in oxygen flow at 900 °C. Secondary ion mass spectroscopy shows that hydrogen dissociation from Mg-doped Al 0.17 Ga 0.83 N is found to be enhanced by annealing in a flow of oxygen, compared with annealing in a flow of nitrogen. We confirmed the effect of activation annealing in oxygen flow on the performance of UV light-emitting diode (LED). At a DC current of 100 mA, the output power of the LED annealed in oxygen flow at 900 °C is four times higher than that of the LED annealed in nitrogen flow at 800 °C.

Summary Transmission and scanning electron microscopic investigations were carried out to characterize Cr-35Re alloy. A continuous film of precipitates at the grain boundaries and precipitates inside the grains were observed. Identification of the phases was based on the analysis of the chemical composition and the diffraction patterns. It has been found that the matrix is a solid solution of Re in Cr and sigma phase CrRe2 was one of the phases present at the grain boundaries. In the majority of the precipitates chromium, rhenium and nitrogen were detected, which indicates the existence of a ternary compound.

High quality semiconducting ternary compound ZnGeP2 was synthesized by a modified two-temperature technique using high purity elemental zinc, germanium and phosphorus as the starting materials. Transport phenomena of zinc and phosphorus vapors and the major reaction intermediates, taking place in ZnGeP2 formation, were studied by interrupting the synthesis process using quenching technique as well as by adjusting the temperatures of cold and hot zones. The powder X-ray diffraction analysis showed that the major reaction intermediates were ZnP2, Zn3P2, and GeP, which proportions were changed at the different temperature stages. ZnP2 was formed in the temperature gradient region and ZnGeP2 was formed in the hot zone when the temperature of the hot zone was higher than 900 °C. The 520-1040 °C temperature profile was chosen for the ZnGeP2 synthesis and charge amount per run reached 200 g. The powder X-ray diffraction pattern of the synthesized ZnGeP2 compound was in agreement with the standard pattern of ZnGeP2. These results demonstrated that the synthesized ZnGeP2 compound was a single phase. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Highly concentrated slurry preparation and low-temperature pressureless sintering of SiC using a novel Al3BC3 additive were investigated. Al+B4C+C powder mixture, which is a conventional sintering additive system of SiC, could not be dispersed in ethyl alcohol above 10 vol%. In contrast, Al3BC3 slurry (average particle size: 0.5 μm) could be prepared up to 50 vol% solid loading and SiC slurry containing 10 wt% Al3BC3 was successfully fabricated up to 45 vol%. The relative density of SiC was 97.9% after pressureless sintering at 1850°C. Young's modulus and hardness of a sintered SiC were 411 and 22.5 GPa, respectively. The present report proposes a method for the low-temperature pressureless sintering of SiC specimens having complex shape and fair mechanical properties by the application of a ternary compound (Al3BC3) as a novel-sintering additive.

Single crystals of CuIn7Se11 ternary compound have been grown by directional crystallization of the melt at first time. The composition of the obtained single crystals was determined by electron probe X-ray microanalysis, X-ray method was used to determine their structure. It was established that the grown crystals are crystallized in hexagonal structure. H2O/CuIn7Se11 photoelectrochemical cells have been created on the given crystals at first time. The photosensitivity spectra from which the character of interband transitions and band gap values have been determined have been investigated. The created photoelectrochemical cells can be utilized as wide-band photoconvertors of an optical radiation. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Alloys of the (CuBiSe2)1–x(CuInSe2)x system with molar part of CuInSe2 (x) equal to 0.05, 0.15, 0.25, 0.375, 0.50, 0.625, 0.75, 0.85, and 0.95 were prepared and the phase relations in this system above 600 K were investigated by using of X-ray powder diffraction, microstructure studies, and differential thermal analysis. It was established, that the T–x phase diagram of the CuInSe2–CuBiSe2 system has a peritectic character with the peritectics temperature of 837 K. The limits of solubility from both sides of the system do not exceed 0.05 molar parts of the corresponding ternary compound. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The measurements of the real part of the dielectric constant and X-ray diffraction studies of different polytypes of TlInS2 crystals are presented in the temperature range T = 160–250 K. Substantial influence polytypism on the occurrence of a polarized state in TlInS2 crystals has been revealed. It is shown that phase transition in 2C-polytype, unlike C-polytype, is not accompanied by a quadrupling of elementary cell along C axes, it is characterized by the other order parameter and occurs at higher temperatures.(© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Evaporated CuInS2 films using a single-source were annealed in H2S atmosphere from 250 to 500 °C for 60 min. after the evaporation. Polycrystalline CuInS2 powder grown by a hot-press method was employed as a source material. Cu/In ratios of the source were 1.0, 1.2 and 1.5. All the films annealed above 350 °C were of CuInS2 single phase regardless of the Cu/In ratio of the source material. The films prepared from the source material of the Cu/In ratio of 1.5 became Cu-rich films, which had the Cu/In ratio of 1.37. Carrier concentrations, resistivities and mobilities of the films annealed above 350 °C prepared from the source material of the Cu/In ratio of 1.5 were approximately 1×1021 cm–3, 0.1 Ωcm and 0.1 cm2/Vs, respectively, at room temperature. The activation energy of the film annealed at 400 °C was evaluated to be 6.5 meV. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Mixed Alkaline Earth Aluminides “AIIAl2” Mixed alkaline earth aluminides near the composition A1IIxA2II1–xAl2 (AII = Ca, Sr, Ba) were synthesized from stoichiometric ratios of the elements in tantalum crucibles; their crystal structures were determined using single-crystal X-ray data. Starting from the binary cubic Laves phase CaAl2 (|:ABC:| stacking of aluminium Kagome nets) up to 73 % of calcium can be replaced by strontium (Ca0.27Sr0.73Al2, cubic, space group , a = 821.2(2) pm; Z = 8, R1 = 0.0083). The new ternary compound Ca1.1Sr5.9Al13 (trigonal, space group , a = 582.35(3), c = 1655.2(2) pm, Z = 1, R1 = 0.0387) forms the structure type originally reported for ‘Ba7Al13’, which exhibits blocks of three Kagome nets ABC as a section of the MgCu2 structure. Blocks of two connected Kagome nets (Sr5Al9 structure type: trigonal, space group , Z = 3) are stable from a Sr proportion of approx. 90 % (Ca0.5Sr4.5Al9: a = 582.61(5), c = 3549.0(6) pm, R1 = 0.0512) through the binary Sr phase up to the barium substituted compound Sr3.9Ba1.1Al9 (a = 590.88(2), c = 3585.2(2) pm, R1 = 0.0212). This structure type is also observed on the Ca–Ba section i.e. at a comparable merged cation radius, between Ca3.3Ba1.7Al9 (a = 578.91(14), c = 3537.7(13) pm, R1 = 0.0462) and Ca2.6Ba2.4Al9 (a = 582.23(6), c = 3570.2(7) pm, R1 = 0.0309). Starting from the binary Ba compound Ba21Al40 (trigonal, space group P31m, Z = 1), only a small Ca (Ca1.9Ba19.1Al40: a = 1048.5(2), c = 1718.3(4) pm, R1 = 0.0624) and Sr substitution (Sr4.3Ba16.7Al40 (a = 1048.64(11), c = 1713.1(2) pm, R1 = 0.0242) is possible without a structure change. Also only a small amount of aluminium can be substituted by Ge (Ba21Al39.2Ge0.8: a = 1053.10(13), c = 1718.4(2) pm, R1 = 0.0576) or In (Ba21Al35.3In4.7: a = 1061.10(9), c = 1738.1(2) pm, R1 = 0.0569) in the latter structure. In this series of compounds near the composition AAl2, the radii of the cations appears to be the decisive element, that governs structure and to some extent even the composition. The available tolerances and the individual site distributions are discussed. For an electronic comparison, FP-LAPW band structure calculations are performed for binary aluminides of all observed structure types and the results are compared to those of the simple electron counting methods.

A platinum-free H(2)/O(2) recombination catalyst, Ti(0.99)Pd(0.01)O(2-delta), is synthesized by a solution combustion method where Pd(2+) ions adsorb protonic H(2)(delta+) ion and oxygen on the oxide ion vacancy sites (see picture). The rate of H(2) + O(2) recombination at 50 degrees C is 15 micromoles g(-1) s(-1), which is much higher than that of Pt-containing catalysts.

A comparative study of chemical bath deposition (CBD) of ZnS, CdS, and a mixture of (Cd,Zn)S buffer layers has been carried out on electrodeposited CuIn(S,Se)2 (CISSe) and coevaporated Cu(In,Ga)Se2 (CIGS) absorbers. For an optimal bath composition with the ratio of [Zn]/[Cd] = 25, efficiencies higher than those obtained with CdS and ZnS recipes, both on co-evaporated CIGS and electrodeposited CISSe, have been obtained independent of the absorber used. In order to better understand the (Cd,Zn)S system and its impact on the increased efficiency of cells, predictions from the solubility diagrams of CdS and ZnS in aqueous medium were made. This analysis was completed by in situ growth studies with varying bath composition by quartz crystal microbalance (QCM). The morphology and composition of the films were studied using scanning electron microscopy (SEM) and X-ray photoelectron spectra (XPS) techniques. Preliminary XPS studies showed that films are composed of a mixture of CdS and Zn(O,OH) phases and not a pure ternary Cd1 − xZnxS compound. The effect of the [Zn]/[Cd] molar ratio on properties of the corresponding CISSe and CIGS solar cells was investigated by current voltage [J(V)] and capacitance voltage [C(V)] characterizations. The origin of optimal results is discussed. Copyright © 2008 John Wiley & Sons, Ltd.

Self-organizing structures of nanometer size are observed on the surface of CdZnTe crystal irradiated by strongly absorbed Nd:YAG laser radiation (LR) at intensities within 4–12 MW/cm2. The effect of exciton quantum confinement manifested by a shift to higher energies of the A0,X exciton band of the photo-luminescent spectrum is present in structures of 10–15 nm in diameter at the top of nano-hills. A graded band gap structure with optical window is formed at the top of nano-hills. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We have applied the full potential linearized augmented plane wave method (FP-LAPW) within the density functional theory to investigate the structural and electronic properties of the Sc 0.5 In 0.5 N compound in the wurtzite and sodium chloride structures. We have analyzed the relative stability of this ternary compound in the two studied phases. We found that the wurtzite structure is the most stable phase, with the minimum ∼0.14 eV/(unit cell) lower than in the sodium chloride phase. A phase transition from wurtzite to sodium chloride structure was observed, with transition pressure ∼ 1.9 GPa. Our results predict a direct semiconductor in wurtzite structure and an indirect semiconductor in sodium chloride phase. We investigate the pressure effect on the electronic properties of this ternary compound in the two phases studied.

We report on our efforts to cultivate the ternary compound ZnCdO as a semiconductor laser material. Molecular beam epitaxy far from thermal equilibrium allows us to overcome the standard solubility limit and to fabricate alloys with band gaps ranging from 3.4 down to 2.1 eV. Optimized structures containing well-defined quantum wells as active zones are capable of low-threshold lasing under optical pumping up to room temperature. The longest lasing wavelength achieved so far is 510 nm.

The structural and electronic properties of Li(4+) (x)Ti(5)O(12) compounds (with 0

We present the synthesis, crystal structure, hardness, IR/Raman and UV/Vis spectra, and FP-LAPW calculations of the electronic structure of Li(2)B(12)Si(2), the first ternary compound in the system Li/B/Si. Yellow, transparent single crystals were synthesized from the elements in tin as solvent at 1500 degrees C in h-BN crucibles in arc-welded Ta ampoules. Li(2)B(12)Si(2) crystallizes orthorhombic in the space group Cmce (no. 64) with a=6.1060(6), b=10.9794(14), c=8.4050(8) A, and Z=4. The crystal structure is characterized by a covalent network of B(12) icosahedra connected by Si atoms and Li atoms located in interstitial spaces. The structure is closely related to that of MgB(12)Si(2) and fulfils the electron-counting rules of Wade and Longuet-Higgins. Measurements of Vickers (H(V)=20.3 GPa) and Knoop microhardness (H(K)=20.4 GPa) revealed that Li(2)B(12)Si(2) is a hard material. The band gap was determined experimentally and calculated by theoretical means. UV/Vis spectra revealed a band gap of 2.27 eV, with which the calculated value of 2.1 eV agrees well. The IR and Raman spectra show the expected oscillations of icosahedral networks. Theoretical investigations of bonding in this structure were carried out with the FP-LAPW method. The results confirm the applicability of simple electron-counting rules and enable some structural specialties to be explained in more detail.

Photocatalytic reduction of Ag 1 2 SO 4 from aqueous solutions is observed in the presence of Dawson-derived sandwich type polyoxometalates (POMs) [M 4 (P 2 W 15 O 56 ) 2 ] 16- , M=Co 2+ , Ni 2+ and Zn 2+ as photocatalyst and an organic substrate (propan-2-ol) as sacrificial electron donor. The direct photochemical excitation of the Dawson-derived sandwich type polyoxometalates in the presence of propan-2-ol leads to its reduction. That first reduction step induces electron transfer to Ag + ions to give Ag° metal atoms which then form by aggregation colloidal metal nanoparticles stabilized by POM. In the case of [Co 4 (P 2 W 15 O 56 )] 16- , TEM experiments reveal that the Ag n particles obtained with a slight excess of Ag+ are almost spherical with size in the range 20 - 50 nm. However, in a large excess of Ag + , the obtained colloids are more oblate and assembled together to give larger aggregates.

A new compound, Na2Zn5(PO4)(4), was identified in the system ZnO-Na2O-P2O5 and high-quality crystal was obtained by the melt method. The crystal structure of this compound was solved by direct method from single crystal X-ray diffraction data. The structure was then refined anisotropically using a full-matrix least square refinement on F-2 and the refinement converged to R-1 = 0.0233 and wR(2) = 0.0544. This compound crystallizes in the orthorhombic system with space group Pbcn, lattice parameters a=10.381(2) angstrom, b=8.507(1) angstrom, c = 16.568(3) angstrom and Z = 4. The structure is made up of 3D [Zn5P4O16](n)(2n-) covalent framework consisting of [Zn4P4O16](n)(4n-) layers. The powder diffraction pattern of Na9Zn21(PO4)(17) is explained by simulating a theoretical pattern with NaZnPO4 and Na2Zn5(PO4)(4) in the molar ratio of 1:4 and then by Rietveld refinement of experimental pattern. Na2Zn5(PO4)(4) melts congruently at 855 degrees C and its conductivity is 5.63 x 10(-9) S/cm. (C) 2007 Elsevier Inc. All rights reserved.

Semiconductor particles composed of CdS and mixed CdS—ZnS were incorporated into the interlayers of layered compounds such as H4Nb6O17, H2Ti4O9, montmorillonite and layered double hydroxides, [M(II)1-xM(III)x(OH)2](CO3)x/2.nH2O(M(II) = Mg2+, Zn2+, M(III) = Al3+, x = 0.33), by the chemical reactions between S2- and Cd2+—Zn2+ and/or Cd(edta)2-—Zn(edta)2- in the interlayers. The incorporated particles seemed to be very small, less than 1 nm thick. The band gap energies of CdS and CdS-ZnS mixtures in the interlayer were significantly larger than those of normal-crystalline ones. The CdS-ZnS mixtures incorporated into the interlayers were capable of efficient hydrogen evolution following irradiation with visible light in the presence of Na2S, Na2SO3 and/or 2-aminoethanol as a sacrificial donor. The hydrogen production activities of the CdS—ZnS mixtures incorporated into the interlayers were superior to those of unsupported CdS—ZnS. The incorporation of the CdS—ZnS mixtures in the interlayer of a semiconductor such as H2Ti4O9 and H4Nb6O17 was much more efficient in enhancing the hydrogen production activity than when an insulator such as montmorillonite and layered double hydroxide was used.

Deformation and cracking behavior of Ge–Sb–Se binary and ternary chalcogenide glasses of varying average covalent coordination number, 〈r〉, was studied by indenting with Vickers and Brinell microindenters using static and recording machines, and subsequent analysis using a non-contact profilometer. Vickers-produced cracks were the smallest around the GeSe4 composition (〈r〉=2.4) after unloading, hence the indentation toughness was a maximum and the brittleness a minimum at 〈r〉=2.4. Brinell-created pond (crater) depth, the mound (pile-up) height, and the radial fractures originating from the mounds displayed minima in the binaries, presumably due to maximized elastic recovery around 〈r〉=2.4. Consequently, Brinell hardness computed from the unloaded depth (HBD) showed a maximum around GeSe4. The maximized elastic recovery around GeSe4 is consistent with Phillips' optimized connectivity arguments. GeSe4 resembles the “anomalous” SiO2 glass for deformation and cracking behavior. Surprisingly, many of the extrema were nearly non-existent in the ternary glasses. The apparent contrast to the binary glasses is not understood.

The solid-state phase equilibria in the Fe–Pd–Pr ternary system at 773 K were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), differential scanning calorimetry (DSC) and energy dispersion spectroscopy (EDS) techniques. It is found that the 773 K isothermal section consists of 14 single-phase regions, 26 two-phase regions, 13 three-phase regions. At 773 K, it is observed that the highest solubility of Pr in FePd and FePd 3 are 1.4 and 1.3 at.% Pr, respectively. The solid solubility of Fe in Pd 5 Pr, Pd 3 Pr, Pd 2 Pr, Pd 3 Pr 2 , Pd 4 Pr 3 , PdPr, Pd 3 Pr 7 , and that of Pd in Fe 17 Pr 2 are very little and less than 1 at.%. In this work, at 773 K, the homogeneity ranges of phases FePd and FePd 3 in the Fe–Pd binary system have been determined to be 49.6–61.1 at.% Pd for FePd and 62.54–80.55 at.% Pd for FePd 3 , respectively. A new ternary compound Pr 6 Fe 13 Pd with space group I 4/ mcm , a = 0.80900 (7) and c = 2.24401 (4) nm was discovered.

Powder and single crystal XRD measurements show that the actual composition of the ternary compound reported as “TbAl2Ge” is close to Tb2Al3Ge3 (refined Tb2Al3.039Ge3).

A new ternary compound NaCu6Se4 was synthesized from the reaction of Cu in a molten sodium polyselenide flux. The compound crystallizes in trigonal space group R3m with a = 4.0465(3) A and c = 41.493(5) A. The crystal structure contains flat two-dimensional slabs of (1)/∞[Cu6Se4] with a unique structural arrangement, separated by Na cations. The compound contains mixed valency and has a high conductivity of ∼3 × 10(3) S cm(-1) at room temperature, and exhibits increasing conductivity with decreasing temperature, indicating metallic behavior. A small positive thermopower (4-11 μV K(-1) from 300 to 500 K) and Hall effect measurements indicate p-type transport with a carrier concentration of ∼2.8(3) × 10(21) cm(-3) and a hole mobility of ∼8.75 cm(2) V(-1) s(-1) at 300 K. NaCu6Se4 exhibits temperature-independent Pauli paramagnetism.