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This paper delves into the transformative impact of varying titanium dioxide (TiO 2) content on the sinterability, physical, and mechanical properties, as well as scratch behavior, of zirconia-toughened alumina (ZTA) ceramic composites. By adjusting TiO 2 content from 0 wt% to 5 wt% and employing advanced microwave sintering at 1150 °C, the study aims to lower the sintering temperature of ZTA. Microwave sintering, known for its efficiency and rapid processing, enables significant enhancements in material properties at reduced temperatures. Notably, incorporating TiO 2 into ZTA yields remarkable improvements in physical and mechanical attributes, with the optimal TiO 2 content determined to be 3 wt%. At this concentration, the composite achieves exceptional properties: a relative density of ∼99 %, microhardness of ∼2002 HV, and an indentation fracture toughness of ∼6.13 MPa m0.5. These enhancements represent increases of over 120 % in hardness and 61 % in toughness compared to TiO 2 -free ZTA. Additionally, the highest scratch resistance is observed at 3 wt% TiO 2 , evidenced by a minimal scratch depth of ∼7.53 μm. However, exceeding the 3 wt% solubility limit results in the formation of secondary phases, such as tialite (Al 2 TiO 5) and zirconium titanate (ZrTiO 4), which degrade the composite's properties. This research underscores the potential of TiO 2 doping and microwave sintering to elevate the performance of ZTA ceramics, offering a pathway to superior materials for advanced applications. [ABSTRACT FROM AUTHOR]

Doped LaCrO 3 perovskites hold promise as robust materials for electrical interconnects and sensor applications in harsh environments. In this work, we investigated the high-temperature behavior of La 1–x Sr x CrO 3 , La 1–x Ca x CrO 3 and La 0.8 Sr 0.2 Cr 1-x Mn x O 3 (0.1 ≤ x ≤ 0.4) through a combination of computational modeling and physical characterization up to 1500 °C. Crystalline structural properties were determined and compared with ab-initio calculations, which demonstrated excellent agreement with experimental findings. High-temperature electrical conductivity measurements were performed under different atmospheres. Calcium and strontium/manganese co-doped lanthanum chromites exhibited typical semiconductor exponential trends and conductivity showed proportional correlation with substitutions levels up to 30%. The DFT modelling was completed up to 1500 °C, including low and high temperature chromite phases and oxygen vacancies insertion. Calculations were correlated with experimental electrical properties. This work expands the understanding of doped lanthanum chromites and paves the way for the development of materials suitable for demanding high-temperature applications. [ABSTRACT FROM AUTHOR]

We applied computing-as-a-service to the unattended system-agnostic miscibility prediction of the pharmaceutical surfactants, Vitamin E TPGS and Tween 80, with Copovidone VA64 polymer at temperature relevant for the pharmaceutical hot melt extrusion process. The computations were performed in lieu of running exhaustive hot melt extrusion experiments to identify surfactant-polymer miscibility limits. The computing scheme involved a massively parallelized architecture for molecular dynamics and free energy perturbation from which binodal, spinodal, and mechanical mixture critical points were detected on molar Gibbs free energy profiles at 180 °C. We established tight agreement between the computed stability (miscibility) limits of 9.0 and 10.0 wt% vs. the experimental 7 and 9 wt% for the Vitamin E TPGS and Tween 80 systems, respectively, and identified different destabilizing mechanisms applicable to each system. This paradigm supports that computational stability prediction may serve as a physically meaningful, resource-efficient, and operationally sensible digital twin to experimental screening tests of pharmaceutical systems. This approach is also relevant to amorphous solid dispersion drug delivery systems, as it can identify critical stability points of active pharmaceutical ingredient/excipient mixtures. [ABSTRACT FROM AUTHOR]

In recent years, there has been considerable interest in the potential of quinones as a promising category of electroactive species for use in aqueous organic redox flow batteries. These materials offer tunable properties and the ability to function as both positive and negative electrolytes, making them highly versatile and suitable for a range of applications. Ongoing research has focused on improving the stability, solubility, and performance of quinones, with a particular emphasis on the creation of stable negolytes. The pairing of these advancements with alternate chemistries has created new prospects for commercial applications. However, challenges persist regarding the stability of quinones in high‐potential electrolytes and the limited number of viable quinones available. Despite these obstacles, significant strides have been made, and the potential for quinones to revolutionize energy storage technology is vast. This review article provides a comprehensive overview of recent progress in this area, with a specific focus on redox potential, solubility, and stability, and offers valuable insights into the future of quinone‐based aqueous organic redox flow batteries. [ABSTRACT FROM AUTHOR]

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In this work, it was aimed to synthesize and characterize rare earth metal-free cerium-based electrolytes that might be used in solid oxide fuel cells (SOFCs) by doping calcium, strontium, or magnesium to CeO2. For this purpose, CeO2, CaxCe(1-x)O(2−δ) (0.16 ≤ x ≤ 0.24), SrxCe(1-x)O(2−δ) (0.02 ≤ x ≤ 0.08) and MgxCe(1-x)O(2−δ) (0.07 ≤ x ≤ 0.13) were prepared by using citrate-nitrate combustion method. The solubility limits, microstructural and physical properties of the samples were characterized with XRD, SEM, TG-DTA and impedance analysis. It was found that all samples were in fluorite structure similar to the undoped ceria. The solubility limits of Ca2+, Sr2+ and Mg2+ were 21%, 6% and 12% (by mole) respectively based on XRD analysis results. The relative densities of sintered pellets at 1400 °C were more than 90%. Electrochemical impedance spectroscopy analysis, in which the ionic conductivities of the samples were measured, revealed that the Ca0.2Ce0.8O2-δ (CCO20) sample sintered at 1400 °C showed the highest ionic conductivity value of 4.47 x10-2 S.cm−1 at 800 °C. It was determined that the O2- ion conductivity decreased with the order of Ca2+ ≈ Sr2+ >> Mg2+. Conductivities increased with increasing dopant ratio, reached a maximum below the ratios of solubility limits, and then decreased. The obtained results showed that Ca or Sr doped electrolytes prepared by the citrate-nitrate method can show ionic conductivities close to the state-of-the-art Sm doped Ceria electrolytes. It has been determined that Mg doping is quite ineffective. [ABSTRACT FROM AUTHOR]

Abstract In recent years, there has been considerable interest in the potential of quinones as a promising category of electroactive species for use in aqueous organic redox flow batteries. These materials offer tunable properties and the ability to function as both positive and negative electrolytes, making them highly versatile and suitable for a range of applications. Ongoing research has focused on improving the stability, solubility, and performance of quinones, with a particular emphasis on the creation of stable negolytes. The pairing of these advancements with alternate chemistries has created new prospects for commercial applications. However, challenges persist regarding the stability of quinones in high‐potential electrolytes and the limited number of viable quinones available. Despite these obstacles, significant strides have been made, and the potential for quinones to revolutionize energy storage technology is vast. This review article provides a comprehensive overview of recent progress in this area, with a specific focus on redox potential, solubility, and stability, and offers valuable insights into the future of quinone‐based aqueous organic redox flow batteries.

Redox flow batteries (RFBs) represent a promising approach to enabling the widespread integration of intermittent renewable energy. Rapid developments in RFB materials and electrolyte chemistries are needed to meet the cost and performance targets. In this review, special emphasis is given to the recent advances how electrolyte design could circumvent the main thermodynamic restrictions of aqueous electrolytes. The recent success of aqueous electrolyte chemistries has been demonstrated by extending the electrochemical stability window of water beyond the thermodynamic limit, the operating temperature window beyond the thermodynamic freezing temperature of water and crystallization of redox‐active materials, and the aqueous solubility beyond the thermodynamic solubility limit. They would open new avenues towards enhanced energy storage and all‐climate adaptability. Depending on the constituent, concentration and condition of electrolytes, the performance gain has been correlated to the specific solvation environment, interactions among species and ion association at a molecular level. [ABSTRACT FROM AUTHOR]

This work investigates the compatibility of ten commercially available accelerators and ten antioxidants with three types of rubber by using molecular dynamics simulation. By constructing fully atomistic models of rubber and small molecules, firstly, the length and number of polymer chains, as well as the number of small molecules are optimized by calculating the solubility parameter. All simulated systems are guaranteed to reach equilibrium by checking the change of the density and energy. Then this work shows that the simulated results match well with each other, which are obtained from the value and the difference of the binding energy of the rubber systems, fractional free volume of the rubber systems, and self‐diffusion coefficient of small molecules calculated from the mean square displacement–time curve. And some small molecules which are more compatible with rubbers are found. More importantly, this study can further determine their compatibility preference by calculating the partition coefficients of small molecules in the rubber blends. Meanwhile, the temperature effect on the change of the compatibility is as well examined. In general, this work provides some guidance for determining the compatibility between rubber and small‐molecule additives, enabling the design of high‐performance rubber materials. [ABSTRACT FROM AUTHOR]

Within a composition range that is of interest for future alloy developments and at a possible application temperature of 700 °C, phase equilibria between Fe3Al and the Nb(Fe,Al)2 Laves phase have been determined. It was found that the solid solubility for Nb in Fe-Al increases by five times, when the Al content increases from about 25 to 35 at.% Al. Besides, the compositions of the co-existing phases, their lattice constants, Curie temperatures, transition temperatures and the solidus and liquidus temperatures of the Fe-Al-Nb alloys, some additionally doped with boron, have been determined. [ABSTRACT FROM AUTHOR]

To ensure the long-term safety and performance efficiency of a deep geological repository for disposal of high-level radioactive waste, understanding and assessment of gas migration behaviour in its engineered barrier system are of significant importance. In this study, a coupled gas transport model is utilised to simulate and to analyse a series of gas injection/breakthrough experiments on saturated bentonite under rigid boundary or constant volume conditions. To explain the laboratory gas migration and breakthrough results, a diffusion and solubility-controlled gas transport mechanism, instead of controversial visco-capillary flow or dilatancy-controlled flow mechanisms, is implemented in the model. The aim is to examine the extent to which this mechanism can describe helium migration and breakthrough behaviours in rigidly confined, saturated bentonite specimens. The predicted results are found to be in good agreement, both qualitatively and quantitatively, with the observed experimental results indicating the adequacy of this mechanism to describe the transport processes. The model represents the gas breakthrough phenomenon as a function of gas solubility. When the dissolved concentration of the injected gas reaches the maximum soluble concentration in the entire porewater domain, gas breakthrough occurs. Since, the system reaches a steady state and no further gas can be dissolved in the rigidly confined specimens, any injected/dissolved gas must be equated by the amount dissipated to comply with the principle of mass conservation. The maximum solution concentrations of helium are predicted to be 2.01 × 10–5, 7.75 × 10–5, 1.07 × 10–4 mol/L for GMZ bentonite specimens with dry densities of 1.3, 1.5 and 1.7 g/cm3, respectively. The analysis of the injection pressure effects on gas migration behaviour revealed that, if sufficient time is permitted, gas breakthrough may occur at pressures lower than the laboratory observed injection pressures. [ABSTRACT FROM AUTHOR]

There is a major knowledge gap and a multifarious problem involving metal chemistry, physical interactions of metals, microbiology, aerobic and anaerobic processes in understanding the precipitation of heavy metals in sewage and polluted water bodies. This study focuses on determining the most feasible metalsalt that can be formed using standard Gibbs free energy change for each possible reaction of all the heavy metals in wastewater. Solubility limits of all possible metal salts are computed. It is shown that even in the short anaerobic stage, any heavy metal will have the propensity to precipitate as sulphides and form insoluble salts, thus rendering the wastewater free from heavy metals. The measured heavy metal concentration in treated wastewater from Bangalore's K-C Valley and Bellandur sewage treatment plants is presented as a validation of the theory. [ABSTRACT FROM AUTHOR]

Dopants and impurities can adsorb to surfaces and grain boundaries in ceramics, influencing the sintering kinetics and grain boundary mobility during processing. Ca is a common impurity in alumina that promotes grain growth at concentrations below the solubility limit, in contrast to the commonly observed solute-drag effect. Knowledge of the Ca solubility limit at temperatures relevant to processing is important to control microstructural evolution. Here we report on the experimentally measured solubility limit of Ca in α-alumina at 1400 °C and 1500 °C from equilibrated and quenched samples using standardized wavelength dispersive spectroscopy to be 32 ± 3 ppm and 45 ± 3 ppm, respectively. Together with the previously measured Ca solubility limit at 1600 °C, the enthalpy (0.95 eV per Ca) and vibrational entropy (-7.35 × 10−4 eV K-1 per Ca) of solution were determined. A negative vibrational entropy of solution indicates coulombic interactions between the Ca cations and charge compensating defects in α-alumina. [ABSTRACT FROM AUTHOR]

The amount of solid solution hardening by some elements was investigated using Fe-25 mass％Cr ferritic steel and Austenitic steels. It was revealed that the hardening amount by Austenite-former elements was considerably larger than that by ferrite-former elements in Ferritic steel. Meanwhile the hardening amount by Ferrite-former elements showed higher value in Austenitic steel, which was a reverse tendency to Ferritic steel. The mechanism was discussed from the point of solubility limit of elements. As a result, the good correlation between the hardening amount and solubility limit was found and the predictive expression of the hardening amount from solubility limit was suggested. [ABSTRACT FROM AUTHOR]

The effects of Cr2O3 substitution on DyBa2Cu3-xCrxO7-δ (x = 0 to 0.70) superconductor were investigated. The samples were characterized by using dc electrical resistance measurements, powder X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) observations. XRD patterns showed impurity peaks for x ≥ 0.2 samples SEM micrographs showed no change in the grain size for x ≤ 0.4. However, partial melting and increase in grain size was observed for higher Cr content (x > 0.4). The orthorhombicity, ε = b − a b + a of the unit cell initially increased with Cr substitution. The resistance-temperature curves showed metallic normal state behavior for x = 0 and semiconductor-like behavior for all Cr-added samples. A pronounced suppression of the transition temperature was observed as soon as Cr was substituted for 0 < x ≤ 0.2 followed by a lower suppression for 0.2 < x ≤ 0.7. Two distinct regions of superconductivity suppression were observed, and the different suppression mechanisms acting in those regions are discussed in this paper. [ABSTRACT FROM AUTHOR]

Investigation of the thermochemical stability of Mg 2 (Si,Sn) thermoelectric materials is crucial for further development of thermoelectric modules. There is a miscibility gap reported for the quasibinary Mg 2 Si–Mg 2 Sn series, though the exact compositions of its limits are disputed. Gaining a better understanding of intersolubility limits in Mg 2 (Si,Sn) is important for further optimization of material performance by exploiting the gap-induced phase segregation. For a better understanding on the boundaries of the miscibility gap below 700 °C, two approaches were taken to provide evidence of thermodynamic stable phases and, hereby, monitor the borders of the miscibility gap. The approaches cover the homogenization of Mg 2 Si x Sn 1- x at 700 °C and diffusion couple experiments at 600 °C, 525 °C, and 450 °C. For 600 °C we find two ranges where Mg 2 Si and Mg 2 Sn are not miscible, namely x = 0.35 ± 0.05 and x = 0.75 ± 0.05 for miscibility gap I and 0.85 ± 0.05 < x < 0.95 ± 0.05 for the second gap. The deduced complex temperature dependence of the mixing / demixing behavior helps to understand the previously observed, apparently contradicting experimental results. We also show that there is no demixing for the compositions with the best thermoelectric properties at temperatures above 700 °C. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The diffusivity of hydrogen is an important property of light water nuclear reactor (LWR) fuel cladding. LWR cladding absorbs hydrogen during normal operation, a contributing factor to embrittlement that decreases the lifetime of the fuel. Mass transport of hydrogen is dictated by an Arrhenius behavior typical of solid state diffusion and the associated activation energy is therefore a property relevant to LWR fuel performance. We have used incoherent quasi-elastic neutron scattering (QENS) to directly measure the diffusivity of hydrogen in recrystallized Zircaloy 2 with a hydrogen concentration of 170 μg/g. We rely upon the low-Q expansion for long-range diffusion to determine diffusivity as a function of temperature between 572 and 780 K. We find the diffusivity is given by D(T) = 0.0067 exp (-0.461 eV/kT) [cm2/s] below 670 K and by D(T) = 0.0012 exp (-0.36 eV/kT) [cm2/s] above 670 K. Our activation energy below 670 K agrees with the value typically used to assess hydrogen diffusivity in LWR cladding [Kearns, Journal of Nuclear Materials 43 (1972) 330], but is approximately 20% lower above 670 K. The two different activation barriers are attributed to impurity trapping of hydrogen solutes at lower temperature that ceases to influence diffusivity at higher temperature. The application of the Oriani model for diffusion with impurity trapping to our system demonstrates the plausibility of this hypothesis. We believe this mechanism may be responsible for historical discrepancies of measured hydrogen diffusivity in Zr-based alloys. The elastic intensity versus temperature in fixed window scans exhibit inflection points that are in good agreement with the published terminal solid solution solubility limits for hydrogen in Zircaloy 2. [ABSTRACT FROM AUTHOR]

Highlights • Development of Tb3+ doped ferrites for MLCI application. • Secondary phases induce lattice distortion and magnetic hardening. • Magnetic behavior of ferrites due to super-exchange interactions. Abstract We report the electric and magnetic properties of nanocrystalline Tb3+ substituted Ni 0.25 Cu 0.30 Zn 0.45 Tb x Fe 2−x O 4 , with x = 0.0–0.125 mol., step: 0.025 mol ferrites, synthesized by glycine assisted autocombustion route. The structural studies confirm the formation of spinel cubic structure for NiCuZn ferrites with the formation of agglomerated polydisperse grains. The presence of two intrinsic IR absorption bands of spinel lattice at ν 1 (760–768) cm−1 and ν 2 (650–665) cm−1 for NiCuZn ferrite system confirms the existence of tetrahedral-A and octahedral-B sites over which the cations are distributed in spinel lattice. Complex permeability measurements signified the decrease in the initial permeability due to spin canting and spin frustration by paramagnetic Tb3+ ions. The frequency dependent dielectric constant of NiCuZn ferrites revealed dielectric dispersion behavior in accordance with Maxwell–Wagner model. The incorporation of rare earth element (Tb3+) in NiCuZn ferrite at relatively lower sintering temperature (1173 K), significantly alters the structural and electromagnetic properties of the host material. Therefore, the present Tb3+ substituted NiCuZn ferrite system with moderate electrical resistivity and soft magnetic properties are potential candidate for multilayer chip inductor (MLCI) component applications. [ABSTRACT FROM AUTHOR]

Abstract It is challenging to conduct aquatic tests with highly hydrophobic and volatile chemicals while avoiding substantial sorptive and evaporative losses. A simple and versatile headspace passive dosing (HS-PD) method was thus developed for such chemicals: The pure liquid test chemical was added to a glass insert, which was then placed with the open end in the headspace of a closed test system containing aqueous test medium. The test chemical served as the dominating partitioning donor for establishing and maintaining maximum exposure levels in the headspace and aqueous solution, without direct contact between the donor and the test medium. The HS-PD method was cross validated against passive dosing with a saturated silicone elastomer, using headspace gas chromatography as analytical instrument and saturated vapors as reference. The HS-PD method was then applied to control the exposure in algal growth inhibition tests with the green algae Raphidocelis subcapitata. The model chemicals were C9-C14 n-alkanes and the cyclic volatile methyl siloxanes octamethyltetracyclosiloxane (D4) and decamethylpentacyclosiloxane (D5). Growth rate inhibition at the solubility limit was 100% for C9-C13 n-alkanes and 53 ± 31% (95% CI) for tetradecane. A moderate inhibition of 11 ± 4% (95% CI) was observed for D4, whereas no inhibition was observed for D5. The present study introduces an effective method for aquatic toxicity testing of a difficult-to-test group of chemicals and provides an improved experimental basis for investigating toxicity cut-offs. Graphical abstract Image 1 Highlights • Passive dosing via the headspace established and maintained constant exposure. • Headspace passive dosing was cross validated by silicone rod passive dosing. • Aquatic toxicity testing of volatile hydrophobic chemicals exactly at saturation. • Algal growth inhibition limit tests showed toxicity of alkanes and D4, but not D5. [ABSTRACT FROM AUTHOR]

In this study, it is examined the significant variations in the superconducting, electrical and structural belongings of Bi-site Gd nanoparticle substituted Bi-2223 crystal. The Bi2.0-xGdxSr2.0Ca2.1Cu3.2Oy (0≤x≤0.3) materials obtained with the standard solid state reaction technique are characterized by dc resistivity (ρ-T), X-ray diffraction (XRD) and transport critical current density (Jc) measurements. Moreover, all experimental findings as regards room temperature resistivity, residual resistivity, critical transition temperatures (Tconset-Tcoffset), crystallinity, lattice constant parameters, average crystallite size, phase fraction and strength quality of interaction between superconducting grains in the Bi-2223 ceramics declare that the structural, electrical and superconducting characteristics degrade systematically with the ascending of the Gd substitution level in the Bi-2223 samples. Furthermore, the major reason of the reduction trend observed especially in the electrical and superconducting features is in relation with the hole localization problem in the Cu-O2 layers. In this regard, grain boundary weak connections, dislocations and defects in the matrix considerably ascend with the enhancement of Gd nanoparticle substitution level. As seen from XRD measurements, it is clearly determined that there seems to be a decrement in the Bi- 2223 phase with the enhancement of Gd inclusions up to the substitution amount of x=0.1. After this critical point, new characteristics peaks of Gd2O3 appear and measurement findings rapidly diminish to the minimum values. This substitution level emphasizes that the solubility limit of Gd is noted to be x=0.1 for Bi-2223. Likewise, the regular decrement observed c-axis length, critical current density and grain size favors the regular retrogression of the superconducting characteristics. [ABSTRACT FROM AUTHOR]

Abstract: Atomistic computer simulation is used to calculate the Gibbs energy at 300 K in the α and γ modifications of Nb5Si3, which are reinforcing phases in in situ composite materials based on the Nb-Si system. The calculations are carried out for boron and carbon atoms at interstitial sites. The calculated change in the Gibbs energy ΔG300 K and crystal chemistry analysis are used to conclude about the referred localization and solubility of boron and carbon atoms in the structures of the α and γ modifications of Nb5Si3. [ABSTRACT FROM AUTHOR]

Understanding the evolution of nitrogen (N) across Earth's history requires a comprehensive understanding of N's behaviour in the Earth's mantle – a massive reservoir of this volatile element. Investigation of terrestrial N systematics also requires assessment of its evolution in the Earth's atmosphere, especially to constrain the N content of the Archaean atmosphere, which potentially impacted water retention on the post-accretion Earth, potentially causing enough warming of surface temperatures for liquid water to exist. We estimated the proportion of recycled N in the Earth's mantle today, the isotopic composition of the primitive mantle, and the N content of the Archaean atmosphere based on the recycling rates of N in modern-day subduction zones. We have constrained recycling rates in modern-day subduction zones by focusing on the mechanism and efficiency of N transfer from the subducting slab to the sub-arc mantle by both aqueous fluids and slab partial melts. We also address the transfer of N by aqueous fluids as per the model of Li and Keppler (2014) . For slab partial melts, we constrained the transfer of N in two ways – firstly, by an experimental study of the solubility limit of N in melt (which provides an upper estimate of N uptake by slab partial melts) and, secondly, by the partitioning of N between the slab and its partial melt. Globally, 45–74% of N introduced into the mantle by subduction enters the deep mantle past the arc magmatism filter, after taking into account the loss of N from the mantle by degassing at mid-ocean ridges, ocean islands and back-arcs. Although the majority of the N in the present-day mantle remains of primordial origin, our results point to a significant, albeit minor proportion of mantle N that is of recycled origin ( 17 ± 8 % or 12 ± 5 % of N in the present-day mantle has undergone recycling assuming that modern-style subduction was initiated 4 or 3 billion years ago, respectively). This proportion of recycled N is enough to cause a departure of N isotopic composition of the primitive mantle from today's δ 15 N of −5‰ to − 6.8 ± 0.9 ‰ or − 6.3 ± 1.2 ‰ . Future studies of Earth's parent bodies based on the bulk Earth N isotopic signature should take into account these revised values for the δ 15 N composition of the primitive mantle. Also, the Archaean atmosphere had a N partial pressure of 1.4–1.6 times higher than today, which may have warmed the Earth's surface above freezing despite a faint young Sun. [ABSTRACT FROM AUTHOR]

PbTiO 3 /PbFe 12 O 19 composites have been synthesized by keeping the Fe concentration ( x ) in PbFe x Ti 1−x O 3 beyond solubility limit, i.e., x > 0.1% and 5% Pb excess. Both these factors have been successfully utilized to extract Fe doped PbTiO 3 tetragonal phase which is composited with Magnetoplumbite (PbFe 12 O 19 ) phase. A systematic evolution of the tetragonality of the former and improved stoichiometry of the later constituent has been observed. As x increases, emergence of additional Raman mode around 650 cm −1 with Fe addition was observed. Systematic increase in the relative intensity of this mode with x , showed that this mode corresponds to the magnetoplumbite phase. In addition to that resultant composite exhibited noticeable systematic decrease in the value of the energy gap as a function of x . Increasing Fe concentration in PbTiO 3 constituent, led to monotonic decrease in c / a and in c re a se in strain experienced by PbTiO 3 . Increase in the value of the saturation polarization was observed up to x = 0.4, which is identified to be associated with the strain induced by the dopant. A comprehensive magnetic characterization revealed monotonic decrease in magnetization with temperature for all compositions. Finally, we found an anomalous temperature dependent trend in the magnetic coercivity which is explained in terms of low temperature decrease in effective magnetic anisotropy by including magneto-electric coupling. Both constituent phases in the composite being ferroelectric and ferromagnetic at room temperature led to formation of better multiferroic properties and exhibited tunable physical properties with x . [ABSTRACT FROM AUTHOR]

The cobalt silicide CoSi seems a suitable material for thermoelectricity: it is inexpensive and non-toxic, but its thermal conductivity is large. Forming CoSi-based alloys by replacing part of Co or Si with a heteroatom M can change electronic properties and improve thermoelectric performances. The insertion energy of different CoSi-based alloys containing abundant, inexpensive and non-toxic elements was estimated by using DFT calculations. Several alloys were synthesized using arc-melting or powder reaction and then characterized using X-Rays powder Diffraction (XRD) and Electron Micro Probe Analysis (EMPA) to determine the limit of solubility of these heteroatoms within CoSi. DFT predictions of solubility limit were in qualitative agreement with experimental results. Vibrational and thermoelectric properties were measured for alloys containing highly soluble elements (Mn and Cr) but also poorly soluble ones (Ti and V). These new CoSi-based alloys, studied for the first time for thermoelectric applications, do not exhibit a notable improvement of the performances. [ABSTRACT FROM AUTHOR]

(8YSZ) 1- x (FeO 1.5 ) x ( x =0, 0.02, 0.08, 0.14 and 0.16) was synthesized by co-precipitation. Crystalline structure, microstructure, electronic conductivity and total conductivity were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Hebb-Wagner method and DC van der Pauw method, respectively, and the effects of FeO 1.5 content on the above properties were investigated. XRD showed the solubility limit of FeO 1.5 in YSZ to be between 14 mol% and 16 mol%. SEM analysis showed FeO 1.5 dopant to promote YSZ sintering and densification. (8YSZ) 0.86 (FeO 1.5 ) 0.14 had the highest electronic conductivity compared to other samples which increased with the decrease of oxygen partial pressure. Total conductivity of samples increased to a maximum and then decreased slightly with the increase of FeO 1.5 content. [ABSTRACT FROM AUTHOR]

A series of oxides LaCaZrO ( x = 0.00, 0.05, 0.10, 0.15, 0.20) is synthesized. It is found that in samples with the calcium content x = 0.15, 0.20, the second phase CaLaZrO is present in the fraction increasing with the increase in x. The solubility limit of calcium to form solid solutions based on LaZrO corresponds to x = 0.1. By high-temperature gravimetry, the proton concentration in LaСаZrO is obtained as a function of temperature in the interval of 300-950°С in НО-О atmosphere. According to temperature programmed desorption studies, in the temperature range of 400-900°С at least two types of OH defects with different binding energies are present in the oxide lattice. The temperature dependences of conductivity are obtained for LaСаZrO in dry and humid air atmosphere in the temperature range of 350-800°С by the method of impedance spectroscopy. The electrolyte conductivity in humid air is shown to substantially exceed the corresponding values in dry air, which can be associated with manifestation of protonic conductivity in humid atmosphere. The dependences of oxide conductivity on the oxygen content in the gas phase are determined. The conductivity is divided into its ionic and hole components. [ABSTRACT FROM AUTHOR]

Reactive diffusion in the Cu-Sn binary system has been studied by using pure Cu /electrically plated Sn with 0.1-0.2 mm thicknesses diffusion couples (EP-couples) at 473 K. The interdiffusion coefficients, $$\tilde{D}$$ , of the CuSn and CuSn diffusion phase layers were determined at the center of these layers by supposing linear concentration ( $$C_{\text{i}}$$ )-distance ( X) curves in these layers and by neglecting the interdiffusion in the Sn terminal solution (IDS) as the previous researchers have neglected it. By using $$\tilde{D}$$ thus determined, the phase boundary concentrations for the layers obtained in this work and these parameters for the Cu terminal solution chosen appropriately, $$C_{\text{i}}$$ - X curves were determined numerically for various values of interdiffusion coefficient, $$\tilde{D}_{\text{in Sn}}$$ , and the solubility limit of Cu mole fractions, $$N_{\text{Cu}}^{\text{in Sn}}$$ , in the Sn terminal solution by our method reported previously taking the molar volume change effect into account. The $$C_{\text{i}}$$ - X curves obtained experimentally could be reproduced numerically well by neglecting IDS. This result, on the other hand, suggests a large influence of IDS in the semi-infinite diffusion couples (S-couples) or the diffusion couples used by the previous researchers. The quantitative evaluation of the influence in S-couples revealed that it makes the widths of the diffusion layers thinner than those in the present EP-couples in which the influence on the widths is negligibly small. The evaluation of the influence in the diffusion couples used by the previous researchers indicates larger values of $$N_{\text{Cu}}^{\text{in Sn}}$$ than those reported as the value of the equilibrium phase diagram. [ABSTRACT FROM AUTHOR]

The crystal structure modifications of BaTiO3induced by cobalt doping were studied. The polycrystalline (1 −x)BaTiO3+xCo2O3samples, withx≤ 10 wt.%, were prepared by high temperature sintering conventional method. According to X-ray phase and structural characterization, performed by full-profile Rietveld refinement technique, all synthesized samples showed tetragonal symmetry perovskite structure with minor amount of parasitic phases. Pure single-phase composition has been detected only in the low level of doping BaTiO3. It was indicated that substitution of Co for the Ti sites in the (1 −x)BaTiO3+xCo2O3series led to decrease of tetragonality (c/a) of the BaTiO3perovskite structure. This effect almost vanished in the (1 −x)BaTiO3+xCo2O3samples with nominal Co content higher than ∼1 wt.%, in which precipitation of parasitic Co-containing phases CoO and Co2TiO4has been observed. Based on the results, the solubility limit of Co in Ti sub-lattice in the (1 −x)BaTiO3+xCo2O3series is estimated asx= 0.75 wt.%. [ABSTRACT FROM AUTHOR]

Measurement of the solubility limit of Si in yttrium aluminum garnet (YAG-Y 3 Al 5 O 12 ) is crucial for understanding the mechanisms by which Si influences grain boundary mobility, and the mechanisms by which grain boundaries migrate. In the present work, the solubility limit of Si in YAG at 1700 °C in vacuum (5 × 10 −6 Torr), which are the most common sintering temperature and environment for YAG, was measured for the first time. Measurements were conducted by wavelength dispersive spectroscopy (WDS), using polished YAG specimens with 3700 ppm Si (0.8 wt% SiO 2 ). Si content to ensure saturation with Si. The accuracy of the WDS result was confirmed by using a series of doped specimens and by comparing to inductively coupled plasma mass spectrometry ICP-MS results. The results indicate that the solubility limit of Si in YAG at 1700 °C (5 × 10 −6 Torr), is 980 ± 60 ppm. The measured Si solubility was found to significantly depend on the cooling rate, where for furnace cooled specimens the measured Si solubility was 650 ± 60 ppm. A second phase in triple junction was repeatedly observed when higher content of Si was used, confirming this work results. [ABSTRACT FROM AUTHOR]

Present study is focused on the structural, electrical and magnetic properties of dilutely Y doped NiFe 2 O 4 nanoparticles. X-ray diffraction confirms the phase formation and shows that samples prepared using sol-gel method exhibit pure spinel phase except that of x = 0.05. Analysis of diffraction pattern and scanning electron microscopy images demonstrate that crystallite as well as particle sizes are increasing with concentration of Y. Presence of impurity phase is further confirmed by Raman measurement. There is no significant change in vibrational modes up to the solubility limit (x = 0.03), however, these modes are shifted towards higher wavenumber for 5% Y doped Ni ferrite due to impure phase. Incorporation of dilute amount of Y ions in host lattice results in an enhancement in the saturation magnetization, coercivity and resistivity. The enhanced saturation magnetization and resistivity is understood on the basis of exchange interactions induced by the substitution of Y 3+ ions for Fe 3+ ions at B-site. [ABSTRACT FROM AUTHOR]

Zr–2.5Nb and Excel pressure tubes, both containing α and β phases were submitted to different heat treatments. Then, hydrogen Terminal Solid Solubility for Dissolution (TSSD) and Precipitation (TSSP) curves were measured by Differential Scanning Calorimetry (DSC). The solvus of Excel heat treated at 380 °C–24 h or 750 °C–0.5 h exceeds the solvus of Zr–2.5Nb in standard conditions of CANDU pressure tubes. Aging at 500 °C–168 h decreases the limit of solubility. The lowest solubility was obtained in Excel aged at 500°C–168 h. In DSC measurements the effect of maximum temperature and hold time at such temperature on solubility curves were studied. The TSSD decreases when thermal cycle causes decomposition of the β phase, and is recuperated when α → α + β transformation temperature is exceeded. The TSSP is affected not only by βZr phase decomposition but also by the relief of defects produced during hydride precipitation. [ABSTRACT FROM AUTHOR]

Cerium substituted yttrium iron garnet films with a chemical formula Y 3− x Ce x Fe 5 O 12 ( x =0.0–0.3) have been successfully prepared by a sol–gel method. The microstructure analysis showed that all films exist in the cubic garnet structure. The lattice parameter and grain size increased with the increment of Ce concentrations up to 0.25, indicating the complete Ce substitution in yttrium site. For a film with x =0.3, the lattice parameter remained unchanged and grain size decreased. The film thickness increased and surface roughness varied with the increment of Ce content. All of the films have high optical transparency (above 80%). The Ce content reduced the saturation magnetization of the film up to a certain limit where above this limit the value increased. Overall, the findings showed that the films with x ≤0.25 exhibited very excellent properties, hence they are promising materials for magneto-optical devices. [ABSTRACT FROM AUTHOR]

In this work, the effect of ZnO precipitation on the electrochemical cycling stability of Zn-air batteries was systematically investigated. The results suggest that sustained electrical rechargeability can be achieved by simply appropriately choosing the amount of Zn metal anode, such that the amount of zincate ions released into the electrolyte upon full discharge of the anode is below the supersaturated solubility limit. For example, there was almost no capacity fading up to 50 cycles when the anode was designed such that the amount of zincate ions released into the electrolyte was a bit less than the chemical solubility limit of ZnO in KOH solution. Despite its limited energy density, the results presented in this study provide an important direction to the future work on electrically rechargeable Zn-air batteries. [ABSTRACT FROM AUTHOR]