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Crystal structure, bandgap, and the changes in the charge conduction mechanisms in ceramics are interrelated, and the underlying physics unifies all these different phenomena. The experimental and theoretical evaluation of the electronic properties of the solid solution of (1 − x)BaTiO3–(x)LaFeO3 (x = 0, 0.015, 0.031, 0.062) is attempted in this work. Bandgap was observed to be tunable with La/Fe doping from 3.2 eV (x = 0) to 2.6 eV (x = 0.06), while the lattice disorder was found to increase. A theoretical assessment confirms a considerable shift of valence band maxima and conduction band minima with an introduction of additional defect states within the bandgap. Electron localization was also confirmed theoretically with doping. Such changes in the electronic properties were experimentally confirmed from dielectric/AC - conductivity/impedance spectroscopy studies. From different transportation models, hopping is a preferred mechanism in the less distorted BaTiO3. However, a large polaron tunneling process can be justified for the doped samples at lower temperatures. Only at higher temperatures, a small polaron tunneling can be justified for the doped samples. The transportation is affected by the grain boundaries as much as the grains themselves. A complete analysis using Nyquist plots reveals the competing contributions of these regions to the transportation mechanism and is correlated to the disorder/distortions in the lattice in terms of the formation of oxygen vacancies. [ABSTRACT FROM AUTHOR]

Interdiffusion experiments are usually time-consuming and tedious since diffusion couples must be annealed at several temperatures for a long time. The efforts required to study interdiffusion in multicomponent alloys increase dramatically as multiple diffusion couples are required to cover broad composition ranges and determine the diffusivities of individual elements in different chemical environments. To circumvent this challenge, we present a high-throughput approach applicable to single-phase and compositionally complex alloys, which are assumed to approximate ideal solid solutions. Here, a simple diffusion-multiple experiment combined with a physically based kinetic model is proposed to efficiently determine the diffusion coefficients of the constituent elements in quaternary CrFeCoNi alloys. Compared with tracer diffusivities reported in the literature, the results, thus, obtained do not differ by more than a factor of 2 and were obtained from a single interdiffusion experiment. In contrast, the diffusivities simulated with commercial mobility and thermodynamic databases are strongly overestimated by a factor ranging from 1 to 16. Therefore, our approach enables high-throughput determination of diffusivities and can help in the design of alloys for high-temperature applications where diffusion plays a key role. [ABSTRACT FROM AUTHOR]

Terminal solid solutions in the Zn O 1 − x S e x system (0 ≤ x ≤ 0.15 , 0.95 ≤ x ≤ 1) exhibit extreme bandgap reduction attributable to band anti-crossing (BAC). In this work, we perform a theoretical investigation of alloying in this system (0 ≤ x ≤ 1). The temperature-composition phase diagram of Zn O 1 − x S e x is obtained via first principles and cluster expansion-based Monte–Carlo simulations. For 0 ≤ x ≤ 0.05 , a solid solution in the wurtzite structure and for 0.5 ≤ x ≤ 1 , a solid solution in the sphalerite structure is obtained. The alloy system exhibits a miscibility gap in the range of 0.05 ≤ x ≤ 0.5. Only the solid solutions are seen to obey bandgap reduction predicted by BAC. The bandgap of the alloys, calculated using the Δ -sol method, shows a bowing behavior as predicted by the BAC model. Difference in the electronegativities of O and Se atoms in the lattice leads to hybridization of O-2p and Se-4p electronic states. Interaction between these electronic states also leads to a split in the valence band edge at the O-rich end and a split in the conduction band edge at the Se-rich end. The effective mass, estimated from the density of states, of holes at the O-rich end and that of electrons at the Se-rich end, increases with alloying. These fundamental insights should help in choosing suitable alloy compositions for optimal photocurrent density when these materials are used as photoanodes. [ABSTRACT FROM AUTHOR]

The combination of optical and mechanical properties of calcium lanthanum sulfide (CLS) makes it an attractive material for optical applications. CLS is a γ -phase La2S3/CaS solid solution above 50:50 La2S3/CaS. Experiments have characterized the effect of composition on the structural, thermal, and optical properties. However, the effect of impurities and other defects, such as porosity, on resulting properties is difficult to deconvolute. We used the density functional theory (DFT) simulations to characterize the effect of La2S3/CaS relative fractions on structural, electronic, mechanical, and vibrational properties of single crystalline CLS solid solutions. We find a decrease in the stiffness with CaS fraction and confirm the experimentally observed increase in the lattice parameter with La2S3 fraction. We also characterized the point defects, including sulfur vacancies, oxygen substituting sulfur, oxygen, and sulfur impurities on lanthanum sublattice vacant sites, and sulfur substituting calcium (vS, OS, OLa, and SLa, respectively). Our defect studies in 90:10 CLS find the neutral charge state configuration to be energetically favorable for all tested configurations except for the sulfur vacancies (vS). [ABSTRACT FROM AUTHOR]

Dielectric energy storage capacitors offer great potential in pulsed power devices due to the high power density and fast charging-discharging rate. Designing a host material with high field-induced polarization is of importance for developing dielectric energy storage materials via further composition modulation. In this paper, we compare the microstructure, dielectric, and ferroelectric properties as well as the energy storage performance of samples K1/2Bi1/2TiO3(KBT), 75KBT-25BiFeO3 (KBTF25), and 88KBT-12Bi0.85Nd0.15FeO3 (KBNTF12) in detail. It is found that, among three samples, sample KBNTF12 possesses the most complex local structure coexisting of a four-distortions with different polarities; meanwhile, sample KBNTF12 behaves as a strong relaxor, thus giving a high field-induced polarization. Besides, sample KBNTF12 realizes the highest electric breakdown strength Eb among three samples, which is resorted to the highest resistivity of grain boundary. Highest ΔP and Eb of sample KBNTF12 among three samples render it achieve ultrahigh stored energy density Ws of 6.94 J/cm3, high recoverable energy density Wr of 5.23 J/cm3, and high efficiency η of 75.4%. Our work suggests that 88KBT-12BNF binary composition be an optimal candidate for dielectric energy storage ceramics. [ABSTRACT FROM AUTHOR]

Morphotropic phase boundary of ferroelectric solid solutions attracts interest with respect to not only improved piezoelectric properties but also the electrocaloric effect, which is attractive to build new-generation cooling devices. In the present study, the electrocaloric effect in (1 − x − y)Na0.5Bi0.5TiO3–xBaTiO3–yNaNbO3 near its morphotropic phase boundary is studied by direct measurements of temperature change ΔT. ΔT maximum is observed in the region of depolarization temperature, where the major contribution comes from an entropy jump at the electric field-induced phase transition. Differences between ΔT values measured when an electric field pulse is applied and removed are explained by slow domain rearrangement in the ferroelectric phase and metastability of phases close to the depolarization temperature. Among studied compositions, the highest value of ΔT is obtained for the compositions 0.94Na0.5Bi0.5TiO3–0.06BaTiO3 and 0.93Na0.5Bi0.5TiO3–0.06BaTiO3–0.01NaNbO3 in the region of depolarization temperature. Examples of the comparison of the directly measured values of ΔT and the values calculated using the Maxwell relation revealing inconsistency between the two methods in the ferroelectric and the nonferroelectric phase are presented. [ABSTRACT FROM AUTHOR]

The solid solution Ba 1 − x Sr x TiO 3 (BSTO) displays dielectric response that is highly tunable, while also exhibiting low losses in a broad frequency regime, including the microwave band. Therefore, there is a need for a better understanding of the influence of the BSTO microstructure on its relaxor properties and performance in a variety of technological applications. Since the local polarization in BSTO is strongly dependent on composition, so is its response to an applied AC field. In this work, we have adopted a phase field method to study the frequency-dependent dielectric response of this system while accounting for the local fluctuations in the solid-solution composition. By utilizing a thermodynamic potential that includes spatial dependence on the averaged Sr content, we connected relaxor-like features in the dielectric dispersion to local spatial inhomogeneities, such as average size of Sr- or Ba-rich regions, across a wide range of temperatures. These results show that the adopted simple coarse-grained approach to the relaxor problem is sensitive enough to reveal correlations between the frequency and temperature dependence of the dielectric response and modulations in the material morphology and microstructure. [ABSTRACT FROM AUTHOR]

Much effort has been expended to obtain thin films of metastable solid solutions of germanium (Ge) that contain as high tin (Sn) content as possible because of their excellent electronic and optoelectronic properties. On the basis of our previous study on amorphous Ge, we demonstrated in this study that irradiation of substrate-free films of amorphous Ge100−xSnx (x = 8, 11, and 19 at. %) with a low-energy electron beam of 3 keV at ambient temperature can induce instantaneous wide-area crystallization (explosive crystallization). Characteristic spiral crystal growth associated with explosive crystallization occurred with areas exceeding 50 μm in diameter around a scanned area of the electron beam of 8 × 8 μm2. As a result, solid solutions of GeSn with Sn concentration up to 19 at. % were obtained with the suppression of precipitation of β-Sn. The region of explosive crystallization reduced in size with increasing Sn content. In addition, thermal analyses revealed that the heat released during crystallization of amorphous GeSn films decreased with increasing Sn content. This relationship indicates that the heat release at the growth front plays a key role in the propagation of explosive crystallization of a-GeSn. [ABSTRACT FROM AUTHOR]

The initial stages of contact melting and eutectic crystallization in sharp concentration gradients between two crystalline components are studied and simulated analytically and numerically. Contact melting is shown to become possible only after the formation of some critical width of solid solutions. Crystallization in the sharp concentration gradient may lead to the formation of periodic structures in the interface vicinity. In addition, at least for the eutectic systems of Ag–Cu type, the threshold temperature should exist, under which the "precipitation + growth" mechanism of crystallization may be changed to "polymorphic crystallization with eutectic composition + subsequent spinodal decomposition." [ABSTRACT FROM AUTHOR]

Fully compensated ferrimagnetic half metals have attracted great attention in spintronics. Unlike many previous calculations based on hypothetical ordered alloys, here we look for existing solid solution series taking as an example Co1−xCrxS2. Calculations find that a low-spin state for Cr that matches early experiments and a fully compensated ferrimagnetic half metal with Curie temperature above room temperature is found at x ≈ 0.33. Our study demonstrates the method of combining two half metals with light and heavy 3d metals in a solid solution to achieve compensation, where atomic disorder does not destroy the desired properties. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (AZIBs) have emerged as competitive alternatives for energy storage systems. By comparison with traditional cathode materials, the unique combination advantages of improved specific capacity, high electrical conductivity and tunable structures exhibited by chalcogenides contribute to receiving increasing attention. However, it should be noted that chalcogenides still show unsatisfactory electrochemical performance in aqueous batteries, because of their inferior chemical stability and sensitivity to pH value in aqueous media. Consequently, the application of chalcogenides in AZIBs still requires further investigation and optimization. This review offers a systematic summary of recent advancements in the rational design strategies employed to develop advanced cathode materials derived from chalcogenides. Furthermore, the review comprehensively presents the applications of various transition metal dichalcogenides, as well as sulfur (S), selenium (Se), tellurium (Te), and their corresponding solid solutions, in AZIBs. Lastly, the challenges currently confronting chalcogenides research are deliberated upon, followed by a perspective outlining future directions for practical applications of AZIBs. [ABSTRACT FROM AUTHOR]

Heterovalent ion doping has been playing a remarkably significant role in the microwave dielectric performances of columbite A2+Nb 2 O 6 (A2+ = Zn, Ca, or transition metal). Here, the Q × f value of MgNb 2 O 6 ceramics can be effectively enhanced from 32,893 GHz to 117,659 GHz by doping with 1 mol% (TiW)5+. Based on the high Q value of Mg(Nb 0.98 Ti 0.01 W 0.01) 2 O 6 , TiO 2 was selected to further adjust the τ f value of the matrix material prepared by the conventional solid-state reaction method. The results show that the Mg(Nb 0.98 Ti 0.01 W 0.01) 2 O 6 ceramics undergo three phase zones with increasing TiO 2 content: columbite (MgNb 2 O 6) solid solution, a mixture of columbite and rutile (Ti 0.5 Mg 0.167 Nb 0.333 O 2), and Ti 0.5 Mg 0.167 Nb 0.333 O 2 solid solution. This variation in phase formation has an essential effect on the microwave dielectric behavior of Mg(Nb 0.98 Ti 0.01 W 0.01) 2 O 6 @xTiO 2 (0.03 ≤ x ≤ 0.25) ceramics. It is important to note that at x = 0.17, the specimen has excellent microwave dielectric performances, with ε r = 34.79, Q × f = 24,103 GHz, and the τ f of the specimen may be adjust to zero. It is anticipated that these materials will be utilised in contemporary microwave and telecommunication equipment. [ABSTRACT FROM AUTHOR]

The damage mechanisms of Ti 3 AlC 2 ceramics during laser processing in air and water were studied using the pulsed laser. The focused high-energy laser induced the melting of surface of Ti 3 AlC 2 ceramics, causing the decomposition of Ti 3 AlC 2 into TiC and Al with Al rapidly evaporating. During the laser processing in the air, oxygen diffused inward to form a solid solution of TiC x O y , and the rapidly heating and cooling of resolidified layer generated high thermal tensile stresses to result in a large amount of microcracks. When processing in the water, the thermal stresses were greatly weakened, and the outward diffusion of Al steam resulted in the voids on the sample surface. Additionally, it is determined that after treating in the air and water, the residual flexural strengths of Ti 3 AlC 2 ceramics could retain the high values of 292 MPa and 484 MPa, and the Weibull moduli were kept at 7.2 and 16.0, respectively, exhibiting the excellent damage tolerance and high reliability. [ABSTRACT FROM AUTHOR]

For the development of optical technologies aimed at research, diagnostics and operation in a wide spectral range, the creation of new materials capable of being highly transparent and effective for transmitting electromagnetic waves in the visible, IR and THz regions is required. This article studies the properties of single crystals and two-phase ceramics based on solid solutions of the AgCl 0.25 Br 0.75 – TlCl 0.74 Br 0.26 and AgCl 0.25 Br 0.75 – TlBr 0.46 I 0.54 systems. The materials showed transparency in the range of 0.4–60.0 and 350–1500 μm (0.20–0.86 THz). With an increase in the proportion of thallium halides in the AgCl 0.25 Br 0.75 solid solutions, a shift and the transmission spectrum broadening to longer wavelengths was observed. These effects are typical for compounds with both Fm3m and Pm3 m type cubic crystal lattice. The refractive indices of the developed materials have normal wavelength dispersion and vary from 2.107 to 2.539 depending on the system and composition. The indicators for solid solutions with an intermediate composition of homogeneity regions lie within the values characteristic of boundary compositions. Based on this data a description of the index dependence by the Sellmeier equation, adapted by Fleming, was obtained. The refractive indices imaginary parts of all developed materials were 0.11*10−4–3.55*10−4, which was 2–4 times lower in comparison with other substances based on silver and thallium halides. The materials were characterized by a photostability improvement with an increase in the part of thallium halides in the solid solution, as well as with a growth in the amount of the orthorhombic phase in the case of two-phase ceramics. The materials showed low values of optical losses, as well as high functional properties. This makes single crystals and ceramics promising for transmission and fiber optics designed to operate in a wide spectral range. [ABSTRACT FROM AUTHOR]

Resin-bonded Al–Si–SiC composite was sintered in the air, and the oxidation mechanism was investigated utilizing industrial CT, XRD, and SEM, combined with thermodynamic calculations, as well as a reaction model, was established. The generation of Al 4 C 3 is avoided by constructing the Al-Si alloy (l) intermediate phase. Simultaneously, AlN exists as a solid solution, which improves the stability of the composite. With temperature increasing, the antioxidant properties of the Al–Si–SiC composite are enhanced by forming a dense layer, and the oxidation mechanism varies at different temperatures. At 1100 °C, the outer layer of Al and Si oxidized to generate Al 2 O 3 and SiO 2 , respectively, while the inner layer generated irregular granular AlN–SiC solid solution; At 1300 °C, the outer pores were filled densely with Al 2 O 3 and SiO 2 , while the high temperature and low Po 2 /Pθ induced active oxidation of SiC in the inner layer so that Po 2 /Pθ was further reduced and the AlN–SiC solid solution particles grew up; At 1500 °C, Al-Si alloy (l) rapidly seals the outer pore channels, accompanied by the in-situ formation of mullite and dense layers, where only N 2 (g) is free to diffuse inward, followed by the continuous dissolution of C and N in a form of atoms in the Al-Si alloy (l) to generate hexagonal granular AlN–SiC solid solution. [ABSTRACT FROM AUTHOR]

(KMg)3+ co-doped Sc 2 W 3 O 12 ceramics have been prepared via co-precipitation method. Effects of (KMg)3+ co-doping amount and sintering temperature on the phase constitution, microstructure, morphology, and negative thermal expansion (NTE) performance of K x Mg x Sc 2- x W 3 O 12 (0 ≤ x ≤ 1.25) ceramics were studied. Results indicate that: Sc3+ cations can be substituted by (KMg)3+ dual-cations and a composition-induced structural phase transition was observed in K x Mg x Sc 2- x W 3 O 12. For x ≤ 0.25, orthorhombic Sc 2 W 3 O 12 gradually changed into hexagonal K x Mg x Sc 2- x W 3 O 12 and coexisted. Single phase K x Mg x Sc 2- x W 3 O 12 with hexagonal symmetry can be prepared for 0.25 < x ≤ 1. When x ≥ 1.25, (KMg)3+ substitution reaches its solid solution limit in Sc 2 W 3 O 12 , and impurity MgWO 4 formed in the samples. As co-doping amount x increased, the NTE performance of the K x Mg x Sc 2- x W 3 O 12 (0 ≤ x ≤ 1) ceramics gradually enhanced. The coefficient of thermal expansion (CTE) of K x Mg x Sc 2- x W 3 O 12 (0 ≤ x ≤ 1) ceramics enhanced from −2.14 × 10−6 °C−1 to −19.68 × 10−6 °C−1 in 30–700 °C. With the increase of sintering temperature from 800 to 1100 °C, the grains grew up and the density of the K 0.75 Mg 0.75 Sc 1.25 W 3 O 12 ceramics increased as well, and the NTE performance was also improved. The linear CTE of K 0.75 Mg 0.75 Sc 1.25 W 3 O 12 ceramics enhances from −2.15 × 10−6 °C−1 to −14.70 × 10−6 °C−1 in 30–700 °C. [ABSTRACT FROM AUTHOR]

[Display omitted] • Coupling Fe doping and S vacancy engineering enables synergistic effect to improve electrocatalysis. • In-situ XRD reveals Co 6 Fe 3 S 8 undergoes surface reconstruction during OER and remains stable during HER. • Simulations prove Fe doping and unsaturated coordination metal sites optimize the adsorption of intermediates. • Co 6 Fe 3 S 8 with rich S vacancy as both anode and cathode deliver a low cell voltage of 1.48 V at 10 mA cm−2. Co 9 S 8 has been extensively studied as a promising catalyst for water electrolysis. Doping Co 9 S 8 with Fe improves its oxygen evolution reaction (OER) performance by regulating the catalyst self-reconfigurability and enhancing the absorption capacity of OER intermediates. However, the poor alkaline hydrogen evolution reaction (HER) properties of Co 9 S 8 limit its application in bifunctional water splitting. Herein, we combined Fe doping and sulfur vacancy engineering to synergistically enhance the bifunctional water-splitting performance of Co 9 S 8. The as-synthesized Co 6 Fe 3 S 8 catalyst exhibited excellent OER and HER characteristics with low overpotentials of 250 and 84 mV, respectively. It also resulted in the low Tafel slopes of 135 mV dec−1 for the OER and 114 mV dec−1 for the HER. A two-electrode electrolytic cell with Co 6 Fe 3 S 8 used as both the cathode and anode produced a current density of 10 mA cm−2 at a low voltage of only 1.48 V, maintaining high stability for 100 h. The results of in/ex-situ experiments indicated that the OER process induced electrochemical reconfiguration, forming CoOOH/FeOOH active species on the catalyst surface to enhance its OER performance. Density functional theory (DFT) simulations revealed that Fe doping and the presence of unsaturated coordination metal sites in Co 6 Fe 3 S 8 promoted H 2 O and H* adsorption for the HER. The findings of this study can help develop a strategy for designing highly efficient bifunctional water splitting electrocatalysts. [ABSTRACT FROM AUTHOR]

In this study, CaMg 0.5 Co x Ni 0.5-x Si 2 O 6 (0.0 ≤ x ≤ 0.5) solid solutions with a diopside structure were prepared to reduce the cobalt and nickel amounts compared to M 2 SiO 4 or MgMSiO 4 (M = Co, Ni) compounds or CaCo x Ni 1-x Si 2 O 6 solid solutions. Colloidal gels were obtained by adding an ammonia aqueous solution to the suspensions of precursors in aqua until pH = 10. Diopside structure began to develop at 800 °C and at 1000–1200 °C crystallinity and pink colour of materials (x ≠ 0) are optimal. In both CaMg 0.5 Co x Ni 0.5-x Si 2 O 6 (0.0 ≤ x ≤ 0.5) and MgCo x Ni 1-x SiO 4 (0.0 ≤ x ≤ 1.0) solid solutions with diopside and olivine structures the position of the third transition of octahedral Co(II), 4T 1 → 4T 1 (P), is centred into the green absorption range and the observed colour is pink. A higher red amount in diopside than in olivine structure can be explained by the minor width of band of this third transition (minor distortion of octahedral M1 site) and shorter mean M1-O distances (M = Ni, Co). [Display omitted] [ABSTRACT FROM AUTHOR]

Chemical looping air separation (CLAS) represents a promising approach to use thermal energy for high-purity oxygen production. CeO 2 represents a class of material that uncouples oxygen using thermal energy, but the required temperature is usually very high (>1400 °C). This limits the potential use for CeO 2 -based materials in CLAS. This study reports a Pr doped CeO 2 oxygen sorbents for chemical looping air separation at ultra-low temperatures. The as-formed Ce 1-x Pr x O 2 solid solution can uncouple oxygen effectively, achieving a redox oxygen capacity of 0.88 wt% at isothermal condition as low as 500 °C. The redox oxygen capacity can be further enhanced to 1.63 wt% in temperature-swing cycles between 400 °C and 900 °C. Moreover, oxygen partial pressure-swing cycles show that the Ce 1-x Pr x O 2 solid solution maintains 95% of its redox oxygen capacity at oxygen partial pressure as low as 0.02 atm, indicating its potential applications in oxygen separation from diluted air. DFT calculations and other physio-chemical characterizations indicate that Pr doping can effectively reduce the oxygen vacancy formation energy, and gaseous oxygen is uncoupled when Pr4+ and Ce4+ are reduced in the Ce 1-x Pr x O 2 solid solution. Overall, this study highlights the novel performance of CeO 2 with Pr doping and could offer insights into CeO 2 modification strategies for thermal chemical applications. [ABSTRACT FROM AUTHOR]

In this work, ZnSe-based polycrystalline ceramics were successfully synthesized from Se and Zn powders in the range of 2.0 GPa and 900 °C–1400 °C by using the high-pressure and high-temperature (HPHT) method. From the acquired experimental results, it was revealed that the fabricated samples were composed of ZnSe with a sphalerite structural type. More specifically, the samples consisted of lamellar and granular grains, and the stomata of the samples showed a trend of first increasing and then decreasing as a function of the elevated temperature. In addition, the infrared transmittance of ZnSe ceramics in the 4 to 18-μm range increased and then decreased by increasing the temperature. When the temperature exceeded the value of 1000 °C, the internal zinc surplus and selenium deficiency of zinc selenide ceramics induced a decrease in the mechanical and optical properties of the ceramics. By optimizing the conditions of the experimental process, the ZnSe synthesized at 1300 °C exhibited better performance with a transmittance of 55%. [ABSTRACT FROM AUTHOR]

The behavior of axisymmetric cylinders under various surface loading has remained the topic of research for many years. Most of the solutions presented in the literature are load-specific. Therefore a general solution is sought to satisfy any boundary conditions prescribed on any surface. This paper presents a general solution to satisfy a wide combination of boundary conditions prescribed on the curved as well as on the flat ends of a cylinder. A hollow cylinder was considered, composed of transversely isotropic material. The formulation is based on the variational principle, resulting in a set of coupled governing equations and associated boundary conditions. The solutions to the coupled governing partial differential equations are obtained by systematically decoupling them, followed by the method of separation of variables and the Frobenius method. All the boundary conditions are satisfied by making use of either the Fourier or the Fourier–Bessel transformation. The solutions for various test cases were validated by comparing them against three-dimensional solutions obtained using finite-element analysis. The solution for the solid cylinder was obtained by considering the limiting case of the internal radius approaching Zero. [ABSTRACT FROM AUTHOR]

To investigate the quantitative relationship between the crystal structure and composition of Mn-bearing calcite, the solid solutions of Ca1–xMnxCO3 (x = 0.1, 0.3, 0.5, 0.7, 0.9) with continuous MnCO3 mol% content were synthesized at 1 GPa and 700 °C using high-purity CaCO3 and MnCO3 powders as starting materials. The run products were analysized by electron probe, powder X-ray diffraction and Raman spectroscopy. The CaO wt% and MnO wt% of the resulting products are consistent with the expected compositions. The powder X-ray diffraction results show that the products are single phase without any impurities. All diffraction peaks of samples with varying MnCO3 mol% contents can be indexed by the calcite-type structure carbonates ACO3 (R-3c space group; A is a divalent cation), confirming the previous results that there is the completely continuous solid solution between CaCO3 and MnCO3 end members. The unit-cell parameters and volumes of the solid solutions decrease as the MnCO3 mol% content increases, presenting a linear relationship of Ca–Mn ideal miscibility, which is perfectly consistent with the rigid body model of A-site substitution in ACO3. Besides, as MnCO3 mol% content increases, the bond distance of A–O decreases linearly, while the bond distance of C–O changes like a parabola. Therefore, the addition of Mn makes the bond distance of A–O shorten, resulting in the decrease of unit-cell parameters and volumes for Ca1–xMnxCO3. Furthermore, two exterior vibrations (T and L) of the crystal lattice and two internal vibrations (ν4 and ν1) within the CO32− unit are assigned in the Raman spectra of these solid solutions. The characteristic vibration modes T, L, and ν4 as a whole increase with the increasing of MnCO3 mol% content, whereas the characteristic vibration mode ν1 as a whole decreases with the increase of MnCO3 mol% content. These variations in Raman vibration modes are related to the radius of substituted ions. [ABSTRACT FROM AUTHOR]

Ferroelectric Pb 5 Nb 10 O 30 (PN) tetragonal tungsten bronze (TTB) forms solid solutions that exhibit morphotropic phase boundaries (MPBs). Successful replacement of PN with TTBs containing Bi could advance lead-free TTB MPBs. The most studied Bi containing TTB, K 4 Bi 2 Nb 10 O 30 , was recently demonstrated to be paraelectric, and we have systematically explored the possibility to increase the Bi-content beyond two Bi3+ ions per unit cell aiming to induce ferroelectricity. Higher Bi content was incorporated by either increasing the cation vacancy concentration on the A-site or by B-site substitution with lower valency cations. An additional pyrochlore phase was found in almost all the explored compositions exceeding two Bi3+ per unit cell. The instability of the TTB structure with higher Bi3+ concentrations was investigated in terms of first-principles calculations, combined with chemical considerations and including the tolerance factor. Consequently, an in-plane polarisation found in PN is unlikely to exist in Bi-based TTBs, meaning that Bi3+ cannot fully replace Pb2+ in ferroelectric TTBs. [ABSTRACT FROM AUTHOR]

Herein, we present the results of a study of nanopowders of Ag 6.25 P 0.75 Ge 0.25 S 5 I, Ag 6.5 P 0.5 Ge 0.5 S 5 I solid solutions, and ceramic materials based on them. Nanopowders were obtained by dry grinding in a ball mill and characterized by XRD and SEM. Solid solutions based ceramic materials obtained by annealing of pressed disks were studied by SEM, EDS, EIS, and microhardness measurement. The SEM method revealed a change in the size of crystallites during recrystallization. The frequency dependence of the electrical conductivity is typical for superionic conductors. For ceramics of the composition Ag 6.5 P 0.5 Ge 0.5 S 5 I, a slight increase in ionic electrical conductivity of 3.62 × 10–2 S/cm (30 min) and 3.84 × 10–2 S/cm (60 min) is observed with a decrease in crystallite size. For the entire series of solid solutions of Ag 6+x (P 1−x Ge x)S 5 I, a comparative analysis of the parameters of ceramics made from micro- and nanocrystalline powders (with different grain sizes) with single crystalline samples was performed. [ABSTRACT FROM AUTHOR]

The major drawback of Cr-containing materials is the generation of toxic Cr6+ compounds, especially at high temperatures in contact with oxygen, alkali or alkaline earth elements/oxides/salts. In this work, we compared the oxidation of two different Cr3+ species, (a) Cr 2 O 3 and (b) a solid-solution mixture of Ca(Al,Cr) 12 O 19 and (Al,Cr) 2 O 3 , upon reheating (500–1500 °C) in the presence of CaO, Al 2 O 3 , and SiO 2 under air atmosphere. The mixture of Ca(Al,Cr) 12 O 19 and (Al,Cr) 2 O 3 was found to be more stable (7.5 mg/kg Cr6+) than Cr 2 O 3 (5646 mg/kg Cr6+). Prolonged reheating (up to 24 h) of Cr3+ solid-solution phases at 900 °C reveals a slight increase in Cr6+ (3.0 to 4.8 mg/kg and 7.5 to 9.1 mg/kg for sample M2 and M2-S (with SiO 2), respectively). However, the Cr3+ solid-solution phases in the presence of SiO 2 reveal higher Cr-evaporation than undoped counterparts. Nonetheless, the mixture of (Al,Cr) 2 O 3 and Ca(Al,Cr) 12 O 19 hardly showed reoxidation and was more inert. • Cr6+ generation from different Cr3+ species were tested at high temperatures in the presence of CaO, Al 2 O 3 , and SiO 2. • Cr3+ phase (Cr 2 O 3) liberated excess Cr6+ but Cr3+ solid-solution mixture (Ca(Al,Cr) 12 O 19 & (Al,Cr) 2 O 3) revealed meager Cr6+. • The reoxidation of solid-solution phases follows parabolic reaction kinetics over time. • Solid-solution Cr3+ phases with dopants reveal higher Cr-evaporation than without dopants. [ABSTRACT FROM AUTHOR]

Hydrogen, as a promising energy carrier, can be extracted from renewable biomass derived acetic acid (HAc). Ni-based catalysts supported on solid solution of Sm2−xPrxO3±δ were prepared using a coprecipitation method and evaluated in auto-thermal reforming (ATR) of HAc for hydrogen production. The results revealed that Pr species infiltrated the Sm2O3 lattice and formed a solid solution structure with oxygen vacancy defects, in which the redox process of Sm3+ + Pr3+ Sm2+ + Pr4+ enhanced oxygen mobility, facilitating gasification of the coking precursor and suppressing carbon deposition. DFT analysis also confirmed that Pr doping into the Sm2−xPrxO3±δ solid solution significantly lowered the energy barrier by 112 kJ mol−1 for formation of oxygen vacancies. Additionally, the interaction between Ni0 and Sm2−xPrxO3±δ effectively improved the dispersion of Ni0 metal particles, inhibiting sintering of Ni species. Consequently, the NSP10 catalyst (Ni0.80Sm1.72Pr0.24O3.74±δ) exhibited outstanding catalytic performance for hydrogen production: the conversion of HAc approached 100%, while the hydrogen yield remained stable at 2.75 mol-H2/mol-HAc. [ABSTRACT FROM AUTHOR]

In the last decades, metal ligand cooperativity has intensively been used as tool in homogeneous catalysis for the development of potent catalysts for a variety of applications, above all hydrogenation and transfer hydrogenation reactions. Herein, we report on the synthesis of iminophosphinoyl‐tethered ruthenium carbene complexes and their use in the activation of dihydrogen and the catalytic transfer hydrogenation of p‐fluoroacetophenone. Variation of the N‐substituent to an electron‐withdrawing p‐nitrophenyl group enabled the reversible activation of elemental hydrogen via a 1,2‐addition across the metal carbon double bond both in solution and in solid state. In comparison to the thiophosphinoyl‐tethered carbene complex the presented iminophosphinoyl systems showed a considerably increased catalytic activity in transfer hydrogenation reactions, thus highlighting the tunability of the cooperative behavior of nucleophilic carbene complexes. [ABSTRACT FROM AUTHOR]

Considering that CO2 reduction is mostly a multielectron reaction, it is necessary for the photocatalysts to integrate multiple catalytic sites and cooperate synergistically to achieve efficient photocatalytic CO2 reduction to various products, such as C2 hydrocarbons. Herein, through crystal engineering, we designed and constructed a metal–organic framework‐derived Zr/Ti bimetallic oxide solid solution support, which was confirmed by X‐ray diffraction, electron microscopy and X‐ray absorption spectroscopy. After anchoring Au nanoparticles, the composite photocatalyst exhibited excellent performances toward photocatalytic CO2 reduction to syngas (H2 and CO production rates of 271.6 and 260.6 μmol g−1 h−1) and even C2 hydrocarbons (C2H4 and C2H6 production rates of 6.80 and 4.05 μmol g−1 h−1). According to the control experiments and theoretical calculations, the strong interaction between bimetallic oxide solid solution support and Au nanoparticles was found to be beneficial for binding intermediates and reducing CO2 reduction, highlighting the synergy effect of the catalytic system with multiple active sites. [ABSTRACT FROM AUTHOR]

Considering that CO2 reduction is mostly a multielectron reaction, it is necessary for the photocatalysts to integrate multiple catalytic sites and cooperate synergistically to achieve efficient photocatalytic CO2 reduction to various products, such as C2 hydrocarbons. Herein, through crystal engineering, we designed and constructed a metal–organic framework‐derived Zr/Ti bimetallic oxide solid solution support, which was confirmed by X‐ray diffraction, electron microscopy and X‐ray absorption spectroscopy. After anchoring Au nanoparticles, the composite photocatalyst exhibited excellent performances toward photocatalytic CO2 reduction to syngas (H2 and CO production rates of 271.6 and 260.6 μmol g−1 h−1) and even C2 hydrocarbons (C2H4 and C2H6 production rates of 6.80 and 4.05 μmol g−1 h−1). According to the control experiments and theoretical calculations, the strong interaction between bimetallic oxide solid solution support and Au nanoparticles was found to be beneficial for binding intermediates and reducing CO2 reduction, highlighting the synergy effect of the catalytic system with multiple active sites. [ABSTRACT FROM AUTHOR]

The isotherms of the lattice thermal conductivity λL for the PbSe1-xTex semiconductor solid solutions (х = 0–0.045) were obtained in the temperature range T = (200–600) K. The λL(x) dependences exhibit a general trend to a decrease in λL with increasing x, but the peaks are observed near x = 0.007, 0.015 and 0.0025 indicating the presence of phase transformations. We associated the first peak with a percolation-type phase transition to the impurity continuum and estimated the critical index for λL within the framework of dynamic scaling theory. The second and third peaks were attributed to the self-organization processes in the PbSe1-xTex after the percolation threshold reaching. The effective cross-sections σs for phonon scattering by impurity (Te) atoms were determined experimentally and calculated theoretically using the Klemens theory. The data obtained are another confirmation of our assumption about the presence of such percolation-type phase transition in any solid solution. [ABSTRACT FROM AUTHOR]

The phenomenon of spontaneous dispersion is considered as the cause of the microstratification of metal melts. In a microstratification melt, a violation of long-range order in the arrangement of atoms (LRO) is observed, which corresponds to a dispersed particle size of more than 2 nm. Microseparation occurs due to spontaneous dispersion upon contact of liquid and solid metal or the mixing of two liquid metals. The possibility of spontaneous dispersion was assessed using three different criteria: Volmer's cr iterion, Rehbinder's criterion and the diffusion rate criterion. The diffusion rate criterion was obtained on the basis of the theory of rate processes, which describes how diffusing atoms overcome the interphase boundary. It has been established that Al–Sn melts contain colloidal-scale particles (4 nm), and Al–Si and Al–Ge melts contain atomic-scale particles (0.1 nm). For a system with a continuous series of Cu–Ni solid solutions in dispersion (Cu10Ni90—Cu20Ni80), the particle size is 2 nm. The particle size of the ternary eutectic GaInSn in the dispersion (Ga50In50—Ga50Sn50) is 5.6 nm, and the size of immiscible Cu–Fe melts in the dispersion (Cu80Fe20—Cu60Fe40) is 4.8 nm. Long-range order violations (LRO) and the presence of microlayering with colloidal particles larger than 20 nm were observed in the GaInSn ternary eutectic, in the Al–Sn simple eutectic with the preferential interaction of similar atoms, and in Cu–Fe melts with a monotectic phase diagram. [ABSTRACT FROM AUTHOR]

The synthesis of a family of chiral and enantiomerically pure pyridyl‐diamide (pda) ligands that upon complexation with europium [Eu(CF3SO3)3] result in chiral complexes with metal centered luminescence is reported; the sets of enantiomers giving rise to both circular dichroism (CD) and circularly polarized luminescence (CPL) signatures. The solid‐state structures of these chiral metallosupramolecular systems are determined using X‐ray diffraction showing that the ligand chirality is transferred from solution to the solid state. This optically favorable helical packing arrangement is confirmed by recording the CPL spectra from the crystalline assembly by using steady state and enantioselective differential chiral contrast (EDCC) CPL Laser Scanning Confocal Microscopy (CPL‐LSCM) where the two enantiomers can be clearly distinguished. [ABSTRACT FROM AUTHOR]

Polycrystalline diamond compacts (PDCs) with varying amounts of vanadium were successfully sintered. The mechanical and thermal performance tests showed that the abrasion resistance, impact toughness, and thermal resistance increased by 69%, 202.9%, and 30 °C, respectively. The improved performance can be attributed to the solid solution formed by V 8 C 7 with tungsten carbide (WC) as a reinforcing phase, which eliminated interfacial defects, improved residual stress, and reduced the thermal expansion coefficient. In summary, we successfully developed a novel method for fabricating high-performance PDCs to enhance abrasion resistance and thermal stability, while substantially improving impact resistance, and which have remarkable application prospects. [ABSTRACT FROM AUTHOR]

Aluminum scandium alloys and their intermetallic phases have arisen as potential candidates for the next generation of electrical interconnects. In this work, we measure the in-plane thermal conductivity and electron–phonon coupling factor of aluminum scandium alloy thin films deposited at different temperatures, where the temperature is used to control the grain size and volume fraction of the Al3Sc intermetallic phase. As the Al3Sc intermetallic formation increases with higher deposition temperature, we measure increasing in-plane thermal conductivity and a decrease in the electron–phonon coupling factor, which corresponds to an increase in grain size. Our findings demonstrate the role that chemical ordering from the formation of the intermetallic phase has on thermal transport. [ABSTRACT FROM AUTHOR]

In the present investigation, magnetic and dielectric properties of solid‐solution formed between the YFeO3 with the similar crystal structure of other oxide materials are focused on. Orthorhombic crystal structure of YFeO3 (YFO), Sr2Bi4Ti5O18 (SBT), and ZnSnO3 (ZS) nanomaterials are considered to prepare the solid solutions at 1150 °C/3 h. YFO and solid solutions exhibit the orthorhombic crystal structure, which is conformed through Rietveld refinement using X‐Ray powder diffraction pattern. The decreased average grain size is observed for the solid solution (3.0 μm for YFO and ZS and 2.6 μm for YFO and SBT) when compared to YFO (3.4 μm) through scanning electron microscopy. Oxidation state of each atom/ion/element present in the YFO and solid solutions are conformed through X‐Ray photoelectron spectroscopy studies. The solid solution formed between the YFO and SBT exhibits high magnetization value (2.92 emu g−1) and high coercive filed (67.5 Oe) when compared to solid solution formed between the YFO and ZS (magnetization value = 2.48 emu g−1, and coercive filed = 46.4 Oe) and YFO (magnetization value = 1.91 emu g−1, and coercive filed = 61.8 Oe). High dielectric permittivity (εr), low dielectric loss (tan δ), and low conductivity are observed for the solid solution formed between the YFO and SBT, when compared to other materials in this study. [ABSTRACT FROM AUTHOR]

A calix[3]carbazole-based cavitand was conveniently synthesized. It was found that the cavitand with adjustable conformation could show excellent complexation with fullerenes C60 and C70 in both solution and the solid state. Moreover, the crystal structures of the host–guest complexes show that the cavitand can stack into channel-like architectures, in which fullerenes are orderly arranged inside. [ABSTRACT FROM AUTHOR]

Potassium europium molybdate, KEu(MoO4)2, is an intriguing material known for its efficient luminescence properties attributed to Eu3+ ions and its polymorphic nature. Despite its significance, research on the metastable γ-phase has been limited, with no prior reports on its structure, particle morphology, and luminescence characteristics. In this study, both the stable α-phase and the metastable γ-phase of KEu(MoO4)2 were synthesized using solid-state and hydrothermal reaction methods, and their crystal structures, particle morphologies, and luminescence properties were comprehensively investigated. X-Ray diffraction analysis confirmed the formation of the triclinic α-phase and the orthorhombic γ-phase, with factor analysis results consistent with theoretically optimized structures, facilitating accurate structural determination. Both phases exhibited typical photoluminescence (PL) spectra of Eu3+ ions. However, in the γ-phase, the 5D0 → 7F2 transition appeared as a non-split peak with minimal Stark effect, attributed to differences in structural symmetry between the phases. A red-shift in the PL excitation edge was observed in the α-phase, which was attributed to a narrowed band gap resulting from the broadening of the O-p orbital in the valence band, as indicated by density functional theory (DFT) calculations. Additionally, KEu(MoO4)2 was doped with Y3+ ions to form K(Eu,Y)(MoO4)2, revealing a solid solubility limit of 40% in the α-phase, while the γ-phase displayed no solid solution limit. The estimated critical distance of Eu3+ ions suggested that Eu–Eu interactions contributing to concentration quenching are minimal in the stacking direction but significant in the in-plane direction, operating in the second shell. [ABSTRACT FROM AUTHOR]

Ti 2 GaC is a novel ternary layered ceramic with unique physical and chemical properties such as excellent thermal conductivity, low density, high-temperature oxidation resistance, and corrosion resistance. However, the relatively low strength and hardness of Ti 2 GaC hinder its practical applications as a structural component. To strengthen the mechanical properties of Ti 2 GaC and extend its application range, in this study, (Ti 1-x V x) 2 GaC MAX phase solid solutions with x ranging up to 0.25 were successfully synthesized using a two-step sintering method. (Ti 1-x V x) 2 GaC solid solutions grains showed a typical lamellar structure, where the a lattice constant of (Ti 1-x V x) 2 GaC decreased from 3.0660 to 3.0326 Å and c decreased from 13.3223 to 13.1520 Å. The effects of V content on the solid solution microstructure, crystal structure, mechanical strength, and resistance to friction and wear were evaluated in detail. In addition, the solid solution formation mechanism and fracture damage modes of these materials were discussed. The crystal structure, mechanical properties, electronic properties, and chemical bonding of (Ti 1-x V x) 2 GaC continuous solid solution at x = 0–1 were calculated by DFT. The solid solution enhancement mechanism of (Ti 1-x V x) 2 GaC was explained by analyzing the relationship between the structure and properties. [ABSTRACT FROM AUTHOR]

Defects and oxygen vacancies always play an important role in the properties of ferroelectric films. Here, we prepared (1 − x)BiFeO3–xSrCoO2.5 films by the sol–gel method, and introduced SrCoO2.5 into BiFeO3 to form an unequal solid solution, thereby generating defective dipoles in the film to regulate the ferroelectric photovoltaic effect. It is shown that the appearance of defective dipoles intensifies the asymmetry of positive and negative charges in the lattice and improves the ferroelectric properties of the films, with remanent polarization of 69.2 μC/cm2 in the 0.98BiFeO3–0.02SrCoO2.5 film. Moreover, the addition of SrCoO2.5 also weakens the orbital hybridization of B–O bonds, reducing the bandgap of the film to 2.42 eV. The open circuit voltage of 10 mV and short circuit current of 0.52 μA/cm2 are obtained in the 0.98BiFeO3–0.02SrCoO2.5 film. This work provides a new strategy for regulating the ferroelectric photovoltaic effect. [ABSTRACT FROM AUTHOR]

Developing argyrodite-type, chlorine-rich, sodium-ion, solid-state electrolytes with high conductivity is a long-term challenge that is crucial for the advancement of all-solid-state batteries (ASSBs). In this study, chlorine-rich, argyrodite-type Na6−xPS5−xCl1+x solid solutions were successfully developed with a solid solution formation range of 0 ≤ x ≤ 0.5. Na5.5PS4.5Cl1.5 (x = 0.5), displaying a highest ionic conductivity of 1.2 × 10−3 S/cm at 25 °C, which is more than a hundred times higher than that of Na6PS5Cl. Cyclic voltammetry and electrochemical impedance spectroscopy results demonstrated that the rich chlorine significantly enhanced the ionic conductivity and electrochemical stability, in addition to causing a reduction in activation energy. The Na5.5PS4.5Cl1.5 composite also showed the characteristics of a pure ionic conductor without electronic conductivity. Finally, the viability of Na5.5PS4.5Cl1.5 as a sodium electrolyte for all-solid-state sodium batteries was checked in a lab-scale ASSB, showing stable battery performance. This study not only demonstrates new composites of sodium-ionic, solid-state electrolytes with relatively high conductivity but also provides an anion-modulation strategy to enhance the ionic conductivity of argyrodite-type sodium solid-state ionic conductors. [ABSTRACT FROM AUTHOR]

Gerty T. and Carl F. Cori discovered, during research on the metabolism of sugars in organisms, the important role of the phosphate ester of a simple sugar. Glucose molecules are released from glycogen—the glucose stored in the liver—in the presence of phosphates and enter the blood as α-D-glucose-1-phosphate (Glc-1PH2). Currently, the crystal structure of three phosphates, Glc-1PNa2·3.5·H2O, Glc-1PK2·2H2O, and Glc-1PHK, is known. Research has shown that reactions of Glc-1PH2 with carbonates produce new complexes with ammonium ions [Glc-1P(NH4)2·3H2O] and mixed complexes: potassium–sodium and ammonium–sodium [Glc-1P(X)1.5Na0.5·4H2O; X = K or NH4]. The crystallization of dicationic complexes has been carried out in aqueous systems containing equimolar amounts of cations (1:1; X–Na). It was found that the first fractions of crystalline complexes always had cations in the ratio 3/2:1/2. The second batch of crystals obtained from the remaining mother liquid consisted either of the previously studied Na+, K+ or NH4+ complexes, or it was a new sodium hydrate—Glc-1PNa2·5·H2O. The isolated ammonium–potassium complex shows an isomorphic cation substitution and a completely unique composition: Glc-1PH(NH4)xK1−x (x = 0.67). The Glc-1P2− ligand has chelating fragments and/or bridging atoms, and complexes containing one type of cation show different modes of coordinating oxygen atoms with cations. However, in the case of the potassium–sodium and ammonium–sodium structures, high structural similarities are observed. The 1D and 2D NMR spectra showed that the conformation of Glc-1P2− is rigid in solution as in the solid state, where only rotations of the phosphate group around the C-O-P bonds are observed. [ABSTRACT FROM AUTHOR]

A new family of 16‐membered macrocycles comprising two indole (In) and two quinoline (Q) units, coined In2Q2, was synthesized. Each unit is diagonally located and concatenated in a head‐to‐tail fashion, furnishing a non‐flat saddle‐shaped architecture with C2 symmetry. The synthetic protocol utilizing macrocyclic diamide as a pivotal precursor allowed us to access a series of In2Q2 derivatives bearing various substituents on the periphery. The In2Q2 derivatives and their Zn2+ complexes were emissive in both solution phase and solid state. While the entire architecture of In2Q2 is similar to that of quinoline tetramer TEtraQuinoline, a couple of contrasting physicochemical properties were revealed. [ABSTRACT FROM AUTHOR]

(HfNbTaZrTiMo)C‐Co high entropy carbide cermet was fabricated by conventional vacuum sintering. The effect of WC addition on the mechanical properties of cermets was also investigated. For cermets without WC addition, with the extension of sintering time, the hardness of cermets first rose and then fell, while the fracture toughness showed a decreasing trend. The increase in sintering temperature led to a decline in hardness and an enhancement of fracture toughness. The (HfNbTaZrTiMo)C‐15 wt. % Co cermet sintered at 1450°C for 2 h had the best comprehensive properties, with the hardness and fracture toughness of 16.36 ± 0.17 GPa and 7.19 MPa·m1/2, respectively. After adding WC, there was a typical black core (undissolved (HfNbTaZrTiMo)C phase)‐gray rim (seven‐component (HfNbTaZrTiMoW)C solid solutions) structure in the cermets. Meanwhile, Mo diffused into WC to form (Mo, W)C solid solutions. The formations of (HfTaZrNbMoTiW)C and (Mo, W)C solid solutions resulted in an improvement in hardness. In addition, since the addition of WC enhanced the wettability between carbides phase and Co phase, the comprehensive properties of cermets were improved. The hardness and fracture toughness of the (HfNbTaZrTiMo)C‐42.5 wt. % WC‐15 wt.% Co cermet sintered at 1450°C for 2 h were 17.42 ± 0.06 GPa and 8.22 MPa·m1/2, respectively. [ABSTRACT FROM AUTHOR]

HfO 2 is an attractive thermal barrier coating material component due to its similarity to ZrO 2 and its high phase structure transformation temperature. However, the difficulty of stabilizing HfO 2 in tetragonal phase by rare element doping and non-satisfying fracture toughness greatly limit its application. We report here the structural, thermo-physical properties, ferroelastic toughening mechanism and fracture toughness of plasma-sprayed Y 2 O 3 stabilized ZrO 2 -HfO 2 solid solution ((Zr 1- x Hf x) 0.9 Y 0.1 O 1.95 , YSHZs, x = 0.1, 0.3, 0.5). A new ferroelastic material is found, YSHZ (x = 0.5) possesses relatively high fracture toughness of 3.5 ± 0.2 MPa·m0.5 through the ferroelastic domains swerving under the stress field of a crack. Moreover, YSHZ (x = 0.5) possesses relatively low thermal conductivity of 1.35 W·m−1·K−1 at 1200 °C and useable thermal expansion coefficients of 10.75 × 10−6 K−1. The combination of properties (especially ferroelasticity) bodes well and makes YSHZ (x = 0.5) as a potential TBC material in gas turbine engines application. [ABSTRACT FROM AUTHOR]

Ceria-based solid solutions (Cu x Ce 1-x O 2) with low-content dopant were synthesized by the co-precipitation method. In samples with a high content of copper (x ≥ 0.1) the second phase CuO was observed, which implied that at higher loadings of copper, the formation of bulk CuO clusters on the ceria solid solution surface was observed. According to complex investigation, copper species are well-integrated in the ceria lattice, especially in a subsurface layer that improved the lattice oxygen mobility, which can be attributed to the coupling of the Ce4+/Ce3+–Cu2+/Cu+ redox cycle, the generation of oxygen vacancies, and strongly bonded Cu-[O]-Ce species. [Display omitted] [ABSTRACT FROM AUTHOR]

The reaction between ZrC and iridium powders was studied in the temperature range of 1000–1600°C. The reaction was stated to start at a temperature as low as 1000°C. The only high‐melting intermetallic phase, ZrIr3, was obtained as a substitutional solid solution ZrIr3±δ. A new analytical approach to relating the composition to the lattice parameter of cubic binary substitutional ZrIr3±δ solid solutions was proposed. This approach is based on comparing the distribution by elemental composition and by lattice parameter in a range of ZrIr3±δ solid solutions. This made it possible to determine the lattice parameter of a stoichiometric ZrIr3 phase, a0 = 3.971(5) Å. [ABSTRACT FROM AUTHOR]

This study explores the feasibility of tribological self‐lubricating over a wide temperature range by doping Si and Sn solid solution components on the A‐sites of Ti3AlC2 to adapt to the severe circumstances. The specimens were sintered at 1450°C for 120 min under a pressure of 30 MPa in a vacuum environment, and their dry sliding tribological capabilities against Al2O3 at temperatures ranging from ambient temperature to 800°C were investigated using a rotational ball‐on‐disk tribo‐tester. The findings demonstrated a constantly decreased friction coefficient of Ti3Al0.8Si0.2Sn0.2C2 throughout the temperature range and admirable antifriction at higher temperatures where wear rates were 1–2 orders of magnitude lower than those at room temperature, which was superior to earlier reported Ti3AlC2. The predominant friction surface self‐adaptability mechanisms after solid solution treatment were determined to be tribo‐oxidation wear and tribo‐chemical reactions that played a vital role by examining the microstructural evolutions and tribo‐chemical phase composition on friction surfaces at various temperatures. The tribo‐oxidation‐induced generated lubricant film consisting of TiO2, Al2O3, SnO2 mixture oxide phases, and aluminosilicates was responsible for the decreased friction coefficient and wear rate. [ABSTRACT FROM AUTHOR]

With the advent of the 5G era, while enjoying the convenience of information in our daily lives, we also face the challenge of dealing with increased and more complex electromagnetic (EM) radiation issues. Therefore, finding EM wave absorbing materials for the operating frequency range (2–18 GHz) of most electronic products has become an important aspect of ensuring human health and environmental safety. In this study, a variety of elements were incorporated into (WZrNbTaM)C powders by calculation and design, where M is Ni, Cr, or Ti. Phase and microstructural analysis demonstrated the successful preparation of a single‐phase solid solution with uniform elements distribution. The magnetic properties of the powders containing Ni and Cr elements exhibited significant improvement. Further analysis revealed that both the impedance matching and EM wave attenuation capabilities of (WZrNbTaCr)C and (WZrNbTaNi)C were enhanced, thereby improving their absorption performance. Compared to (WZrNbTaTi)C, (WZrNbTaCr)C and (WZrNbTaNi)C exhibit a significant improvement in minimum reflection loss (RL), with an increase of 27.1% and 37.2%, reaching −45.21 and −48.79 dB, respectively. The maximum effective absorption bandwidth (EAB) has also increased by 22.9% and 48.6%, reaching 3.44 and 4.16 GHz, respectively. It is noteworthy that (WZrNbTaCr)C and (WZrNbTaNi)C achieved these excellent absorption properties while maintaining a matching thickness of 1.07 and 1.17 mm. This lightweight and thin performance meets the requirements for use in special scenarios while ensuring the outstanding absorption performance. [ABSTRACT FROM AUTHOR]

NaBiCe/Sc ions were co‐doped into a pure CaBi4Ti4O15 (CBT) ceramic to investigate the synergistic action of multiple factors that induced a high piezoresponse. In comparison to the undoped CBT ceramic, the NaBiCe/Sc co‐doped CBT solid solution exhibited an enhancement in spontaneous polarization (Ps) attributed to the tilting of the oxygen octahedra, enhanced domain reorientation owing to increased grain size, and improved dielectric breakdown strength as a consequence of reduced porosity. The synergistic action of the aforementioned comprehensive factors resulted in excellent electrical properties of Ca0.6(Na0.5Bi0.5)0.4Bi3.97Ce0.03Ti3.925Sc0.075O15 ceramic: piezoelectric coefficient d33 = 25.0 pC/N, remnant polarization Pr = 9.28 μC/cm2, and coercive field Ec = 76.14 kV/cm. Moreover, a significant high direct current resistivity (ρdc = 1.22 × 107 Ω·cm at 500°C) was achieved, and the corresponding conductance mechanism was analyzed through a synergistic approach that combines ultraviolet–visible diffuse reflectance spectra and density functional theory. [ABSTRACT FROM AUTHOR]

A HfC 0.68 N 0.32 solid solution coating was synthesized on the surface of C/C composites by chemical vapor deposition (CVD). The mechanical properties and ablation resistance of HfC 0.68 N 0.32 coating were investigated under laser and oxyacetylene conditions. Results indicated that HfC 0.68 N 0.32 coating exhibited higher hardness and elastic modulus than HfC and HfN coatings. The phase separation of HfC 0.68 N 0.32 coating generated in the laser ablation environment with power of 800 W, and the mass ablation rate was 0.17 mg/s after ablation for 10 s. Furthermore, the surface temperature of the coated sample reached 2600 ℃ under an oxyacetylene environment with a heat flux density of 4.2 MW/m2, resulting mass and linear ablation rates of 0.34 mg/s and 0.23 µm/s respectively after ablation for 100 s, showing a great potential in the field of ultra-high temperature ablation protection. [ABSTRACT FROM AUTHOR]