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The traditional approach to designing ferroelectrics through phase boundaries has limitations in regulating polarization configuration and achieving significant performance enhancements. In contrast, the concept of high-entropy materials has emerged as a promising strategy for designing new materials with enhanced properties. Herein, by incorporating the high configurational entropy (S config) strategy, the investigation explored the influence of S config on the electrical properties of PNN-PHT piezoceramics. The results demonstrated that high S config values were highly beneficial in improving the piezoelectric properties and significantly influenced the microstructure and grain size. The increase in S config value was found to be positively correlated with the Rayleigh coefficient (α), dielectric loss (tan δ), and frequency dispersion (γ), while inversely correlated with the coercive electric field (E c). By exploring the mechanism via Raman and simulation analyses, it was discovered that high S config induces enhanced disorder, increased lattice distortion, and sharp volume changes. This ultimately resulted in a richer phase structure, reducing the potential energy barriers and leading to a lower activation energy (E a) required for polarization switching. This finding provides novel strategies and directions for the development of high-voltage and high-coercive-field materials, holding promise for designing piezoelectric devices with enhanced power density and precision. [ABSTRACT FROM AUTHOR]

In random sequential adsorption (RSA), objects are deposited on a substrate randomly, irreversibly, and sequentially. Attempts of deposition that lead to an overlap with previously deposited objects are discarded. The process continues until the system reaches a jammed state when no further additions are possible. We analyze a class of RSA models on a two-row square ladder graph in which landing on an empty site in a graph is allowed when at least b neighboring sites in the graph are unoccupied ( b ∈ N ). In this paper we complement this typical way of studying RSA models by analyzing also the structure of the set of all jammed states in a static way, disregarding the dynamics that led to a particular jammed state. In both considered settings (dynamic and static) we provide explicit expressions for key statistics that describe the average proportion of the substrate covered by deposited objects, and then we comment on significant differences between the two settings. We illustrate all of our findings through a toy model for ensembles of trapped Rydberg atoms with blockade range b. [ABSTRACT FROM AUTHOR]

Yttria-stabilised zirconia is used as a thermal barrier coating material and is widely applied in the thermal protection field. However, its tendency to undergo phase transformation at high temperatures poses a significant challenge to the durability of these coatings. An alternative material with superior high-temperature phase stability and a high coefficient of thermal expansion is thus desirable. Rare earth zirconate, such as Gadolinium zirconate (Gd2Zr2O7), has emerged as a promising candidate due to its inherent properties. High-entropy ceramics have attracted much attention due to their excellent properties. Leveraging the design principles of high-entropy systems, the structural configuration of Gd2Zr2O7 has been optimised to enhance its properties. In this work, A-, B- and AB-sites of Gd2Zr2O7 were designed by regulating the configurational entropy. Based on this strategy, seven types of high-entropy powders and ceramic blocks were prepared successfully. The structure and thermal properties of the as-prepared samples were investigated. The results indicate that the configurational entropy within the system and the size disorder parameter are pivotal in determining the thermal stability and thermal conductivity of the as-prepared high-entropy ceramic materials. Notably, the dual-phase high-entropy Gd2(Ce0.2Zr0.2Hf0.2Sn0.2Ti0.2)2O7 ceramic exhibits good thermal stability. The large size and mass difference between the elements results in a reduced mean free path of phonons, thereby reducing the thermal conductivity significantly. The Gd2(Ce0.2Zr0.2Hf0.2Sn0.2Ti0.2)2O7 ceramic demonstrates thermal conductivity that is substantially lower than that of Gd2Zr2O7 and other high-entropy ceramics, which is as low as 0.927–0.850 W m−1 K−1 at 200–800°C. These results indicate that the high-entropy Gd2(Ce0.2Zr0.2Hf0.2Sn0.2Ti0.2)2O7 is an outstanding candidate for application in thermal barrier technology and related fields. [ABSTRACT FROM AUTHOR]

The properties of molybdenum diboride are intricately tied to its crystal structure, which includes two distinct phases, α‐MoB2 and β‐MoB2. The α‐MoB2 exhibits superior electrical and catalytic properties, akin to those of graphite due to the similar HCP structure. Nevertheless, the transformation between α‐MoB2 and β‐MoB2 is complicated and the formation of α‐MoB2 remains challenge due to higher Gibbs free energy. The MoB2 powder synthesized through boro/carbothermal reduction in this study suggests the β phase, transforming into α‐MoB2 completely via a high‐entropy strategy. It founds that the introduction of high‐entropy diborides (HEB) effectively inhibits the grain growth of samples, resulting in a significant enhancement in their hardness. The potential for the formation of a single‐phase between MoB2 and HEB is associated with Pauling electronegativity difference, δχP. Furthermore, the formation of a single‐phase solid solution was found to contribute to the improvement in the fracture toughness of the samples. This work presents a novel strategy for stabilizing α‐MoB2, offering valuable insights into understanding phase‐transition behavior in MoB2 and the solid solubility in multi‐component ceramics. [ABSTRACT FROM AUTHOR]

Incorporating multiple atoms with different masses and radii at distinct atomic sites within a lattice matrix can increase its entropy and, in turn, enable a synergistic approach to both band structure and microstructure engineering. Modifying the band structure enhances electrical transport properties, while changes in the microstructure effectively suppress thermal transport properties, leading to significantly improved thermoelectric performance. Here, entropy engineering is employed to enhance the thermoelectric performance of the SnTe material system. The synergistic alloying of Ge, Mn, and In significantly alters the electronic band structure by merging four valence bands namely L, Σ, Λ, and X, and creating a resonant energy state near the Fermi level, resulting in an outstanding Seebeck coefficient of ≈97 µV K−1 at room temperature. The high density of point defects, Ge secondary phases, amorphous interfaces, phono–phonon interactions, and grain boundaries significantly disrupts the movement of heat‐carrying phonons, leading to an exceptionally low lattice thermal conductivity of 0.32 W m−1 K−1, pushing it below the amorphous limit. Consequently, a peak figure of merit of 1.64 achieves at 873 K in Sn0.71Ge0.2Mn0.07In0.02Te. These findings lay the groundwork for developing advanced thermoelectric materials via entropy engineering. [ABSTRACT FROM AUTHOR]

In order to improve the magnetocaloric properties of MnNiSi-based alloys, a new type of high-entropy magnetocaloric alloy was constructed. In this work, Mn0.6Ni1−xSi0.62Fe0.4CoxGe0.38 (x = 0.4, 0.45, and 0.5) are found to exhibit magnetostructural first-order phase transitions from high-temperature Ni2In-type phases to low-temperature TiNiSi-type phases so that the alloys can achieve giant magnetocaloric effects. We investigate why chexagonal/ahexagonal (chexa/ahexa) gradually increases upon Co substitution, while phase transition temperature (Ttr) and isothermal magnetic entropy change (ΔSM) tend to gradually decrease. In particular, the x = 0.4 alloy with remarkable magnetocaloric properties is obtained by tuning Co/Ni, which shows a giant entropy change of 48.5 J∙kg−1K−1 at 309 K for 5 T and an adiabatic temperature change (ΔTad) of 8.6 K at 306.5 K. Moreover, the x = 0.55 HEA shows great hardness and compressive strength with values of 552 HV2 and 267 MPa, respectively, indicating that the mechanical properties undergo an effective enhancement. The large ΔSM and ΔTad may enable the MnNiSi-based HEAs to become a potential commercialized magnetocaloric material. [ABSTRACT FROM AUTHOR]

Peptides are promising therapeutic agents for various biological targets due to their high efficacy and low toxicity, and the design of peptide ligands with high binding affinity to the target of interest is of utmost importance in peptide‐based drug design. Introducing a conformational constraint to a flexible peptide ligand using a side‐chain lactam‐bridge is a convenient and efficient method to improve its binding affinity to the target. However, in general, such a small structural modification to a flexible ligand made with the intent of lowering the configurational entropic penalty for binding may have unintended consequences in different components of the binding enthalpy and entropy, including the configurational entropy component, which are still not clearly understood. Toward probing this, we examine different components of the binding enthalpy and entropy as well as the underlying structure and dynamics, for a side‐chain lactam‐bridged peptide inhibitor and its flexible analog forming complexes with vascular endothelial growth factor (VEGF), using all‐atom molecular dynamics simulations. It is found that introducing a side‐chain lactam‐bridge constraint into the flexible peptide analog led to a gain in configurational entropy change but losses in solvation entropy, solute internal energy, and solvation energy changes upon binding, pinpointing the opportunities and challenges in drug design. The present study features an interplay between configurational and solvation entropy changes, as well as the one between binding enthalpy and entropy, in ligand‐target binding upon imposing a conformational constraint into a flexible ligand. [ABSTRACT FROM AUTHOR]

Granular materials belong to the class of complex materials within which rich properties can emerge on large scales despite a simple physics operating on the microscopic scale. Most notable is the dissipative behaviour of such materials mainly through non-linear frictional interactions between the grains which go out of equilibrium. A whole variety of intriguing features thus emerges in the form of bifurcation modes in either patterning or un-jamming. This complexity of granular materials is mainly due to the geometrical disorder that exists in the granular structure. Diverse configurations of grain collections confer to the assembly the capacity to deform and adapt itself against different loading conditions. Whereas the incidence of frictional properties in the macroscopic plastic behavior has been well described for long, the role of topological reorganizations that occur remains much more elusive. This paper attempts to shed a new light on this issue by developing ideas following the configurational entropy concept within a proper statistical framework. As such, it is shown that contact opening and closing mechanisms can give rise to a so-called configurational dissipation which can explain the irreversible topological evolutions that granular materials undergo in the absence of frictional interactions. [ABSTRACT FROM AUTHOR]

Cerate is regarded as a promising material for the next-generation of thermal barrier coating due to its high coefficient of thermal expansion (CTE) and low thermal conductivity. However, its thermal contraction within the temperature range of 473-673 K poses a significant challenge to its widespread application. The aim of this work is to improve the thermal contraction by regulating the configurational entropy of cerate ceramics. Six kinds of rare earth doped cerate ceramics with different configurational entropy were prepared. The results indicated that the phases of the as-prepared ceramics are all fluorite structures. With the increase of configurational entropy, the problem of thermal contraction is improved continuously. More importantly, the as-prepared (La 1/8 Sm 1/8 Yb 1/8 Y 1/8 Er 1/8 Eu 1/8 Nd 1/8 Gd 1/8) 2 Ce 2 O 7 (8RC) high entropy cerate ceramic demonstrates a near elimination of thermal contraction in the 473-673 K temperature range, and accompanied by high CTE, low thermal conductivity and good thermal stability, suggesting its potential application in the field of thermal barrier coating material. [ABSTRACT FROM AUTHOR]

Ceramic ion conductors play a pivotal role as electrolytes in solid‐state batteries (SSBs). Aside from the ionic conductivity, their (electro)chemical stability has a profound effect on the performance. Lithium thiophosphates represent a widely used class of superionic materials, yet they suffer from limited stability and are known to undergo interfacial degradation upon battery cycling. Knowledge of composition‐dependent properties is essential to improving upon the stability of thiophosphate solid electrolytes (SEs). In recent years, compositionally complex (multicomponent) and high‐entropy lithium argyrodite SEs have been reported, having room‐temperature ionic conductivities of σion>10 mS cm−1. In this work, various multi‐cationic and ‐anionic substituted argyrodite SEs are electrochemically tested via cyclic voltammetry and impedance spectroscopy, as well as under operating conditions in SSB cells with layered Ni‐rich oxide cathode and indium‐lithium anode. Cation substitution is found to negatively affect the electrochemical stability, while anion substitution (introducing Cl−/Br− and increasing halide content) has a beneficial effect on the cyclability, especially at high current rates. [ABSTRACT FROM AUTHOR]

Asymmetric colloidal Janus particles (JPs) have stimulated research which spans many disciplines, often due to possibilities for their assembly into larger structures. This review aims to identify opportunities for physicists and others working on spherical JPs clustering in bulk fluid, which is a simple and fundamental type of JP assembly. The review focuses on JPs with two hemispheres with differing surface properties but also considers ‘patchy’ particles with smaller or more numerous distinct surface areas. Research to date has featured many simulation methods, including point potentials with angular dependence, multi-site approaches, and detailed numerical techniques. The field lacks experiments and 3D simulations which allow clear quantitative comparisons and hence validation of fundamental principles, including the behaviour of so-called ‘floppy’ bonds between two or more JPs. Research into non-equilibrium clustering and the role of hydrodynamics in assembly will also be of ongoing interest, because these topics will be significant in any practical assembly strategy.

Phase‐change materials (PCMs) are an important family of alloys employed in non‐volatile memories and neuromorphic devices. These devices exploit the ability of PCMs to undergo rapid transitions between amorphous and crystalline phases at moderately high temperature. At ambient conditions, both phases are stable. These properties imply a very strong temperature dependence of the crystallization kinetics, which has been attributed to the high fragility of the supercooled liquid phase. In this work, the fragility index of GeTe, an important PCM, is extracted from a computational exploration of the potential energy landscape of the system by molecular dynamics simulations. For this purpose, a neural‐network potential is used to describe the interatomic interactions, which enables the evaluation of the configurational entropy in the deeply supercooled regime. The viscosity and the relaxation times are also calculated in the same temperature range. Finally, the Adam‐Gibbs relation is used to extrapolate the data to low temperatures and estimate the glass transition temperature and the fragility index. The latter quantity turns out to be of the order of 135–140, which shows that liquid GeTe is a highly fragile system. [ABSTRACT FROM AUTHOR]

Configurational entropy can have a dominating role in the electrical transport behavior and optical bandgap, thereby playing a crucial role in the development of transparent conductive oxides. Here, single-phase perovskite RNiO 3 (R La, Pr, Nd, Sm, Eu) thin films on Mica substrates using chemical solution deposition were fabricated, with varying configurational entropies (low-, medium- and high-entropy system). The structure, optical and electrical properties have been thoroughly investigated. It is revealed that optical bandgap, carrier mobility and carrier concentration in RNiO 3 films depends on the variation of configurational entropy. As configurational entropy increases, carrier mobility decreases due to reduced grain sizes, while the carrier concentration and bandgap increase as a result of metal cations reduction and lattice distortion. Remarkably, a p-type conductivity of 2.3 S/cm and optical transmittance of approximately 50% were achieved in the medium-entropy La 0.25 Sm 0.25 Pr 0.25 Nd 0.25 NiO 3 thin films. This is due to the increased bandgap enhances transparency, while the improved carrier concentration ensures a certain level of conductivity. Furthermore, the La 0.25 Sm 0.25 Pr 0.25 Nd 0.25 NiO 3 thin films demonstrated excellent potential for application in flexible electrodes. These findings confirm that the tuning of transparency and conductivity of perovskite nickelates thin films through configurational entropy is an effective approach to improve the performance of flexible transparent conductive devices. [ABSTRACT FROM AUTHOR]

This paper considers the application of two known models for the evaluation of distortion in high entropy shape memory alloys with the B2 structure. Distortion was calculated using the hard sphere and soft sphere models for binary TiNi and senary Ti-Hf-Zr-Ni-Cu-Co alloys with different chemical composition. It was shown that both models could not be used because they gave a high distortion value even for binary Ti49Ni51 alloy. Distortion was so large for all alloys that they must be amorphous. However, this contradicted the experimental data according to which all alloys were crystalline with the B2 structure. A modification of both models was proposed taking into account that the TiNi alloy is an intermetallic compound. The formation of intermetallic compound was accompanied by a change in the spatial distribution of electron density around the nuclei of interacting atoms, which led to a change in the atomic sizes. The proposed modification gave the distortion value that was consistent with the lattice stability criterion for alloys where the concentration of each alloying element did not exceed 5 at %. [ABSTRACT FROM AUTHOR]

Phase transition generates rapid changes of transport parameters and poor mechanical property, and thus restricts the application of thermoelectric materials. AgBiSe2 exhibits cubic phase at above 580 K with high-symmetry structure and low lattice thermal conductivity, indicating the potentiality of high thermoelectric performances. In this work, the cubic structure of AgBiSe2 was achieved at ambient conditions by alloying with PbS, enhancing the configurational entropy at both cationic and anionic sites. The cubic structure was rather stable after several measurement cycles. Nb substitution at cationic sites effectively reduced band gap, and increased both carrier concentration and effective mass. All samples exhibited relatively low lattice thermal conductivity (0.68–0.34 W/(m·K)) in the temperature range of 300–773 K, due to the nanoscale inhomogeneity and the random distribution of multiple species at some atomic sites. A maximum zT of 0.65 at 773 K was obtained for (Ag0.99Nb0.01BiSe2)0.8(PbS)0.2 sample. The entropy-driven structural stabilization is a promising strategy to achieve stable structure for practical thermoelectric applications.

Half-Heusler alloys (HHs) as medium- and high-temperature thermoelectric materials have attracted increasing considerable attention, owing to their excellent mechanical properties and thermal stability. Nonetheless, the intercoupling between the Seebeck coefficient and electrical conductivity, and their high thermal conductivity limit the furthermore enhancement of their thermoelectric properties. This review systemically summarizes and analyses the various current strategies for improving thermoelectric properties, such as manipulating band structure, optimizing electron and phonon transports, and constructing high configurational entropy, etc. Moreover, the possible deficiencies of the existing electric-phonon transport mechanisms are highlighted and discussed, which aiming to provide a meaningful guide for future efforts to accelerate the development of HHs. Finally, based on current research, a new potential future for the integration of single crystal technology and high-entropy effect is introduced for HHs. [ABSTRACT FROM AUTHOR]

In this article, we study the phase behavior of two polydisperse hydrocolloids: dextran and polyethylene oxide. We combine the data on the experimental osmometric virial coefficients of the pure components with the experimental critical point of their aqueous mixture and the size distribution of each component from a previously published study in order to predict the phase boundary, spinodal, and fractionation upon demixing of the polydisperse mixture. We compare the results of our calculation to the experimental phase diagram. Our method reveals a better correspondence with the experimental binary phase behavior than modeling each component as monodisperse. The polydispersity of the hydrocolloids causes the phase separation boundary to shift to lower concentrations and the miscibility region to decrease and change its shape from a rotated U-shape to a W-shape. [ABSTRACT FROM AUTHOR]

After the discovery of the prototypical high-entropy oxide with formula Cu 0.2 Zn 0.2 Mg 0.2 Co 0.2 Ni 0.2 O, the research on these materials has shown a dramatic boost. While many studies were devoted to exploring their possible applications, only few addressed the effective reasons behind their stability. The possibility to achieve a single-phase structure is usually hastily attributed to configurational entropy. This resulted in an extensive misuse of the terms "entropy-stabilized oxides" and "high-entropy oxides", often employed as synonyms. However, the effective role of entropy in the stabilization should be demonstrated for each system, and even for Cu 0.2 Zn 0.2 Mg 0.2 Co 0.2 Ni 0.2 O it is still under debate. Moreover, many effects concur to the stabilization, i.e. the relative concentration, the valence state and the ionic radii of the cations involved. We will here discuss the role of configurational entropy in the phase stability, considering the main classes of crystal structures and providing a guide to critically discern between entropy and non-entropy stabilized oxides. [ABSTRACT FROM AUTHOR]

In order to improve the magnetocaloric properties of MnNiSi-based alloys, a new type of high-entropy magnetocaloric alloy was constructed. In this work, Mn0.6Ni1−xSi0.62Fe0.4CoxGe0.38 (x = 0.4, 0.45, and 0.5) are found to exhibit magnetostructural first-order phase transitions from high-temperature Ni2In-type phases to low-temperature TiNiSi-type phases so that the alloys can achieve giant magnetocaloric effects. We investigate why chexagonal/ahexagonal (chexa/ahexa) gradually increases upon Co substitution, while phase transition temperature (Ttr) and isothermal magnetic entropy change (ΔSM) tend to gradually decrease. In particular, the x = 0.4 alloy with remarkable magnetocaloric properties is obtained by tuning Co/Ni, which shows a giant entropy change of 48.5 J∙kg−1K−1 at 309 K for 5 T and an adiabatic temperature change (ΔTad) of 8.6 K at 306.5 K. Moreover, the x = 0.55 HEA shows great hardness and compressive strength with values of 552 HV2 and 267 MPa, respectively, indicating that the mechanical properties undergo an effective enhancement. The large ΔSM and ΔTad may enable the MnNiSi-based HEAs to become a potential commercialized magnetocaloric material.

The effect of configuration entropy (ΔSconf) on thermal properties and magnetocaloric effects (MCE) of metallic glasses (MGs) remains vague. In this work, Tb55Co17.5Al27.5 low-, (Gd0.5Tb0.5)55Co17.5Al27.5 medium-, and (Gd1/3Tb1/3Dy1/3)55Co17.5Al27.5 high-entropy (LE, ME, and HE) MGs with critical diameters more than 5 mm were successfully fabricated. Systematic investigations into their thermodynamic behaviors suggest that high ΔSconf might deteriorate glass forming ability (GFA) along with reduced viscosity. Simultaneously, an improved thermal stability was observed in ME and HE MGs for their high activation energies for glass transition, crystal nucleation and growth, while the notable ordered structure in HE MG could accelerate glass transition and crystal growth by reducing activation energies. Studies of MCE indicate that the distinguished spin glass behaviors and higher structural order in HE MGs comprehensively contribute to an enhanced relative cooling power and a broader magnetic-transition temperature range, whereas the change of Curie temperature and maximum magnetic entropy more depends on the de Gennes factor rather than ΔSconf. All three designed MGs manifesting the competitive GFA and MCE could be candidates for magnetic refrigeration. Our studies show that entropy tailoring seems to play a dominant role in determining thermodynamic behaviors, which could help to design more stable MCE MGs.

Glass is a representative of fragile material. But it can be used as a good protective cover when strengthened. As a method of such strengthening, so-called “physical tempering” is widely used for large glass plates. In this method, heated glass is rapidly quenched so that the outside part of the glass is frozen while the inside cools slowly. Such difference in frozen temperatures causes the excessive shrinkage of the inside than the outside, which generates surface compressive stress. Thus, for better strengthening, higher thermal expansion can be expected. In this research, we investigate glass which has similar expansion coefficient while it is in glassy state but is much larger when they are in the supercooled liquid state. We successfully found that the borosilicate glass system possesses systematically controllable thermal expansion at high temperatures while keeping that at a temperature below glass transition to be similar. It was available due to the systematic but drastic change in configurational entropy related to the alkali-assisted-Si-O-B bonding in the series of borosilicate glasses. Two types of tempering demonstrations show that the developed glass can be strengthened more than twice as large as that of the window glass when applied to a similar strengthening condition.

In this article, we study the phase behavior of two polydisperse hydrocolloids: dextran and polyethylene oxide. We combine the data on the experimental osmometric virial coefficients of the pure components with the experimental critical point of their aqueous mixture and the size distribution of each component from a previously published study in order to predict the phase boundary, spinodal, and fractionation upon demixing of the polydisperse mixture. We compare the results of our calculation to the experimental phase diagram. Our method reveals a better correspondence with the experimental binary phase behavior than modeling each component as monodisperse. The polydispersity of the hydrocolloids causes the phase separation boundary to shift to lower concentrations and the miscibility region to decrease and change its shape from a rotated U-shape to a W-shape.

We discuss some general properties of the symmetry-resolved entanglement entropy in systems with particle number conservation. Using these general results, we describe how to obtain bounds on the entanglement components from correlation functions in Gaussian systems. We introduce majorization as an important tool to derive entanglement bounds. As an application, we derive lower bounds both for the number and the configurational entropy for chiral and Cn -symmetric topological phases. In some cases, our considerations also lead to an improvement of the previously known lower bounds for the entanglement entropy in such systems. [ABSTRACT FROM AUTHOR]

Transverse vibrations of bridging atoms in framework structure oxides contribute to negative thermal expansion (NTE), increasing the configurational entropy. Herein, the configurational entropy of NTE (Al 1/3 Fe 1/3 Cr 1/3) 2 Mo 3 O 12 (AFCM) is tuned by introducing ZrMg and W to AlFeCr and Mo sites to lower NTE. The NTE of ((Zr 1/2 Mg 1/2) x (Al 1/3 Fe 1/3 Cr 1/3) (1- x)) 2 Mo 3 O 12 (ZMAFCM) reduce obviously with increasing the content of ZrMg and also the phase transition temperatures (PTTs) (x = 0∼0.5). For ((Zr 1/2 Mg 1/2) x (Al 1/3 Fe 1/3 Cr 1/3) (1- x)) 2 (Mo 1/2 W 1/2) 3 O 12 (ZMAFCMW), the NTE and PTTs reduce at a faster rate than that of ZMAFM. The configurational entropy increases with the content of ZrMg firstly (x = 0∼0.4) and then decreases. The possible mechanism of thermal expansion change is related to the enhanced lattice configuration, high entropy. The inconsistent transverse vibrations of bridging oxygen atoms could reduce their contribution to NTE, especially for high entropy. The PTT of high configurational entropy oxides is reduced obviously due to the influenced on the effective electronegativity. The investigation paves a high entropy way to lower thermal expansion and PTT of A 2 M 3 O 12 oxide ceramics and explores the further mechanism of NTE. [Display omitted] [ABSTRACT FROM AUTHOR]

The physical nature of the phenomenon of negative thermal expansion coefficient seen in the polar crystals and ferroelectrics is considered. Usually it is observed at low temperatures but especially evident in vicinity of ferroelectric phase transitions. This phenomenon is associated with fundamental nature of non-centrosymmetric crystals, caused by electronegativity difference of adjoined ions forming polar crystal. Negative thermal expansion coefficient indicates a change in the nature of forces of the attraction at close proximity of ions forming polar bond. The thermal expansion minimum is specified by the configurational entropy, conditioned by polar bonds self-ordering in pyroelectrics and ferroelectrics. [ABSTRACT FROM AUTHOR]

Many pairwise additive force fields are in active use for intrinsically disordered proteins (IDPs) and regions (IDRs), some of which modify energetic terms to improve the description of IDPs/IDRs but are largely in disagreement with solution experiments for the disordered states. This work considers a new direction-the connection to configurational entropy-and how it might change the nature of our understanding of protein force field development to equally well encompass globular proteins, IDRs/IDPs, and disorder-to-order transitions. We have evaluated representative pairwise and many-body protein and water force fields against experimental data on representative IDPs and IDRs, a peptide that undergoes a disorder-to-order transition, for seven globular proteins ranging in size from 130 to 266 amino acids. We find that force fields with the largest statistical fluctuations consistent with the radius of gyration and universal Lindemann values for folded states simultaneously better describe IDPs and IDRs and disorder-to-order transitions. Hence, the crux of what a force field should exhibit to well describe IDRs/IDPs is not just the balance between protein and water energetics but the balance between energetic effects and configurational entropy of folded states of globular proteins.

The thermostabilization of G-protein coupled receptors (GPCRs), which are important drug targets, is a crucial challenge for structural analysis. We constructed a methodology for thermostabilizing a GPCR in the inactive state or the active state solely by multiple aminoacid mutations without the ligand binding. This method combines our recently developed theory based on statistical thermodynamics and the technique of site-directed saturation mutagenesis, which is frequently used in evolutionary molecular engineering. The methodology was illustrated for the serotonin 2A receptor and the adenosine A2A receptor, and we successfully obtained stabilized multiple mutants. [ABSTRACT FROM AUTHOR]

Although low thermal conductivity and high band degeneracy bring promising thermoelectric performance to cubic SnSe, its preparation strategies remain elusive. Here, a series of Sn 1–2 x (AgBi) x Se samples are synthesized using the vacuum melting (1173 K) and spark plasma sintering (723 K) methods. Owing to the increased configurational entropy caused by AgBiSe 2 solid solution, the cubic structure is obtained when x exceeds 0.2. The optimized carrier concentration significantly enhances electrical conductivity (σ), and maximal σ of 350 Scm−1 is obtained in Sn 0.5 (AgBi) 0.25 Se. Combined with the low lattice thermal conductivity caused by the small sound velocity and strong anharmonicity, the figure of merit of 0.08 is reached in Sn 0.6 (AgBi) 0.2 Se at 500 K. The mechanical performances are also improved, and a high Vicker hardness of 1.5 GPa is obtained in Sn 0.4 (AgBi) 0.3 Se. This work demonstrates the importance of the configurational entropy in phase regulation and provides insights into the design of new thermoelectrics. [ABSTRACT FROM AUTHOR]

Sol-gel auto combustion method has been used to synthesize a series of Mn x Mg 0.8– x Zn 0.2 Fe 2 O 4 (0≤ x ≤ 0.7 at a step of 0.1) nano ferrites. Thermogravimetric and Differential scanning calorimetry (TGA and DSC) studies revealed that the weight loss changes happened up to the temperature 700 °C. A stable ferrite phase without weight loss was found above 750 °C. XRD patterns gave the confirmation of cubic spinel phase of ferrite samples along with the minor amounts of α -Fe 2 O 3 phase. The α -Fe 2 O 3 phase appears to be increasing in the ferrite compositions for x ≥ 0.4. The experimental lattice parameter (a) and average crystallite size (< D >) are found to be in the range of 8.4205–8.4479 Å and 34.9–54.7 nm. A systematic variation was not found in both a and < D > with the substitution of Mn2+. FE-SEM micrographs do not provide individual particle sizes, but their nature showed the agglomeration of ferrite nanoparticles with magnetic interactions. The obtained higher and lower vibrational bands (υ 1 and υ 2) in FTIR spectra confirm spinel phase in support of XRD analysis. The ratio of bulk modulus to rigidity modulus (B / R) is greater than 1.75 for all ferrite compositions showing that the mechanical behaviour is ductile. The value of Poisson ratio (σ = 0.26) revealed the isotropic nature of ferrite compositions. Different parameters like cation distribution, substitution of Mn2+, configurational entropy, secondary phases and bond lengths are predominantly influencing the structural, vibrational and elastic properties of present ferrite compositions. [ABSTRACT FROM AUTHOR]

High entropy perovskite oxides (HEPOs) were a class of advanced ceramic materials, which had attracted much scientific attention in recent years. However, the effect of factors affecting the phase stability of high entropy perovskite oxides was still controversial. Herein, 17 kinds of A-site HEPOs were synthesized by solid-state methods, and several criteria for the formation of HEPOs and phase stability were investigated. Single-phase solid solutions were synthesized in 12 kinds of subsystems. The results show that the phase stability of a single-phase solid solution was affected by the size disorder and configurational entropy. The electronegativity difference was the key parameter to predict the evolution of the cubic/tetragonal phase, rather than the tolerance factor. Cubic HEPOs were easily formed when the electronegativity difference was <0.4, while the tetragonal HEPOs were easily formed when the electronegativity difference was ≥0.4. This study can further broaden the family of HEPOs and is expected to design the phase stability of HEPOs through electronegativity difference. [ABSTRACT FROM AUTHOR]

In our previous study, the coamorphous formulation of lurasidone hydrochloride (LH) with saccharin (SAC) showed significantly enhanced dissolution and physical stability compared to crystalline/amorphous LH. However, the coamorphous system is still in amorphous state, and has the tendency to recrystallization, which will in turn result in the loss of above advantages. In this study, the crystallization kinetics under isothermal and non-isothermal conditions was investigated. Compared to amorphous LH, coamorphous LH-SAC showed 68.3–361.2 and 2.6–6.1 times lower crystallization rates in glassy state and supercooled liquid state, respectively. After co-amorphization, the addition of SAC changed the crystallization mechanism of amorphous LH from nucleation-controlled to diffusion-controlled manner. Amorphous LH followed the site-saturated nucleation, whereas the coamorphous system exhibited a fixed number of nuclei. The non-isothermal crystallization indicated amorphous LH and coamorphous LH-SAC showed two-dimensional (JMAEK 2) and three-dimensional (JMAEK 3) growth of nuclei, respectively. Furthermore, coamorphous LH-SAC exhibited higher molecular mobility and dynamic fragility (m D) than amorphous LH, which is kinetically unfavorable for its physical stability. However, from thermodynamic perspective, coamorphous LH-SAC had a higher configurational entropy, i.e., a higher entropy barrier for crystallization, which is beneficial to hinder its crystallization. Therefore, it was concluded that the higher configurational entropy rather than the molecular mobility was proposed to be responsible for its improved stability. In addition, molecular dynamics simulations with miscibility, radial distribution function and binding energy calculations suggested coamorphous components exhibited good miscibility and strong intermolecular interactions, which was also conductive to the enhancement in its stability. This study offers an in-depth understanding about the effect of the coformer on the crystallization kinetics of coamorphous systems, and points out the important contribution of the configurational entropy in stabilizing the coamorphous systems. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, a series of multicomponent rare-earth zirconate (RE 2 Zr 2 O 7 , RE=La, Nd, Sm, Eu, Gd or Yb) ceramics were synthesized using solid-state reaction method. The phase stability and key factors affecting the thermal conductivity and mechanical performances were investigated. These materials possess pyrochlore-fluorite dual-phase structure and show excellent high-temperature phase stability. (La 1/2 Yb 1/2) 2 Zr 2 O 7 displays a lower amorphous-like thermal conductivity (1.39–1.67 Wm−1K−1, 25–1000 °C), while other specimens present a 1/T-like dependence at low temperatures. (La 1/5 Nd 1/5 Sm 1/5 Gd 1/5 Yb 1/5) 2 Zr 2 O 7 exhibit higher hardness (11.37 ± 0.35 GPa) and fracture toughness (2.10 ± 0.11 MPa·m1/2) in comparison with others. Size disorder shows stronger correlations with the thermal conductivity of multicomponent dual-phase RE 2 Zr 2 O 7 ceramics, while the influence of configurational entropy is more significant for mechanical properties. A synergistic increase in configurational entropy and size disorder is an effective strategy to enhance the comprehensive performance of multicomponent dual-phase rare-earth zirconates. • A series of dual-phase medium- and high-entropy RE 2 Zr 2 O 7 ceramics were tailored and synthesized. • Size disorder shows stronger correlations with the thermal conductivity of multicomponent dual-phase rare-earth zirconates. • Entropy is a more effective descriptor than size disorder for influencing the mechanical properties of these materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Structural entropy can quantify the degree of disorder in materials. • Structural entropy plays a similar role to configurational entropy. • The structural entropy associated with five-fold symmetry undergoes a sharp transition around the glass transition temperature. Drawing on Shannon entropy, we developed a parameter called "structural entropy," which is derived uniquely from atomic configurations and serves to measure the evolution of disorder during the glass transition. We applied this parameter to the glass transition in the CuZrAl system. A comparison with configurational entropy suggests that both may fundamentally encapsulate the same physical concept: the system's level of disorder. This new structural entropy parameter bridges the gap between the macroscopic properties and the microscopic structure of glass, offering insights into the mechanisms underlying the glass transition. [ABSTRACT FROM AUTHOR]

Entropy engineering has emerged as an important means of optimizing the properties of SrTiO 3 -based thermoelectric materials. However, the relationship between configurational entropy and thermoelectric properties is currently unclear. In this work, non-equimolar high-entropy thermoelectric ceramics [Ca (1- x)/3 Sr (1- x)/3 Ba (1- x)/3 La x ]TiO 3 (0.10 ≤ x ≤ 0.40) were prepared by spark plasma sintering. And the effects of composition and configurational entropy on the microstructure and thermoelectric properties of the materials were investigated. It is revealed that high entropy effect profoundly modified the microstructure of the material. The grain size decreases with increasing configurational entropy, the interaction of multiple cations leads to lattice distortions, and the sintering and annealing process induces the creation of oxygen vacancies, which significantly affect thermoelectric properties. The highest ZT (0.20) was obtained at a lanthanum content of 0.19 (Δ S Conf =11.483 J/mol/K). This work provides theoretical and experimental bases for optimizing the thermoelectric properties of the materials by using high entropy design. • Non-equimolar high-entropy perovskite [Ca (1-x)/3 Sr (1-x)/3 Ba (1-x)/3 La x ]TiO 3 (0.10≤ x ≤0.40) ceramics were prepared by spark plasma sintering. • The relationship between configuration entropy and thermoelectric parameters of ceramics was clarified. • The composition of x =0.19 with higher thermoelectric properties was optimized. [ABSTRACT FROM AUTHOR]

Entropy engineering in thermoelectric materials involves a deliberate manipulation of entropy-related effects to boost performance. It revolves around designing materials to capitalize on entropy-driven changes, breaking conventional trade-offs between properties like electrical and thermal conductivity for improved efficiency. Entropy engineering fosters higher crystal symmetry, altering the Seebeck coefficient by augmenting degenerate valleys in the band structure. The introduction of significant mixing entropy mitigates strain energy, enhancing structural stability. Conversely, severe lattice distortion, atomic mass fluctuations, lattice anharmonicity, multiscale microstructures, and point defects lead to potent scattering of phonons, which suppresses thermal transport properties. This study comprehensively explores the effectiveness of entropy engineering in diverse compounds, aligning with the status and challenges in this field. These insights will guide researchers in refining material design and properties, advancing high-performance thermoelectric materials and devices to revolutionize energy conversion and stimulate sustainable technological advancements. • New perspectives on thermoelectric materials within the framework of entropy engineering. • The comprehension of electrical transport features through crystal symmetry caused by entropy. • Mechanical and device performances of entropy driven thermoelectric materials. • Prospective research avenues for thermoelectric materials based on entropy engineering. [ABSTRACT FROM AUTHOR]

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We challenged the stabilization of a G‐protein coupled receptor (GPCR) in the active state solely by multiple amino‐acid mutations without the agonist binding. For many GPCRs, the free energy of the active state is higher than that of the inactive state. When the inactive state is stabilized through the lowering of its free energy, the apparent midpoint temperature of thermal denaturation Tm exhibits a significant increase. However, this is not always the case for the stabilization of the active state. We constructed a modified version of our methodology combining statistical thermodynamics and evolutionary molecular engineering, which was recently developed for the inactive state. First, several residues to be mutated are determined using our statistical‐thermodynamics theory. Second, a gene (mutant) library is constructed using Escherichia coli cells to efficiently explore most of the mutational space. Third, for the mutant screening, the mutants prepared in accordance with the library are expressed in engineered Saccharomyces cerevisiae YB14 cells which can grow only when a GPCR mutant stabilized in the active state has signaling function. For the adenosine A2A receptor tested, the methodology enabled us to sort out two triple mutants and a double mutant. It was experimentally corroborated that all the mutants exhibit much higher binding affinity for G protein than the wild type. Analyses indicated that the mutations make the structural characteristics shift toward those of the active state. However, only slight increases in Tm resulted from the mutations, suggesting the unsuitability of Tm to the stability measure for the active state. [ABSTRACT FROM AUTHOR]

The demand for high-performance microwave dielectric ceramics has surged with the proliferation of fifth-generation (5G) communication networks. In this work, SrLa(Al 0.50- x Ga x Zn 0.125 Mg 0.125 Ti 0.25 )O 4 ( x = 0-0.20) ceramics were designed by leveraging the unique properties of SrLaAlO 4 ceramics and high-entropy engineering. The effects of configurational entropy ( S conf = 1.23R - 1.54R) on the mechanical, thermal, and microwave dielectric properties of SrLa(Al 0.50- x Ga x Zn 0.125 Mg 0.125 Ti 0.25 )O 4 ceramics were investigated. X-ray diffractometer and transmission electron microscope analyses confirmed that each composition belonged to the tetragonal structure with a space group of I 4/ mmm . Significant improvements in Vickers hardness were observed with increasing S conf , reaching 8.05 GPa at S conf = 1.54R compared to 5.64 GPa in SrLaAlO 4 ceramics. Additionally, the increasing entropy showed great potential in reducing the thermal expansion coefficient (CTE) from 12.32 to 11.49 ppm/°C. The optimal quality factor ( Q × f ) of 98,000 GHz was achieved at S conf = 1.37R, attributed to the optimization of intrinsic lattice energy and infrared-damped modes. The temperature coefficient of resonant frequency (τ f ) was successfully modified toward zero due to entropy-driven CTE and structural modifications. Excellent microwave dielectric properties with ε r = 22.5, Q × f = 98,000 GHz, and τ f = -2.0 ppm/°C were obtained at S conf = 1.37R. This work highlights the potential of entropy-engineering in developing high-performance microwave dielectric ceramics, offering a promising pathway for the advancement of 5G communication components.

The spinel-type LiMn2O4 is a promising candidate as cathode material for rechargeable Li-ion batteries due to its good thermal stability and safety. Experimentally, it is observed that in this compound there occur the structural phase transitions from cubic ( F d 3 ÂŻ m ) to tetragonal (I 41/ amd) phase at slightly below room temperature. To understand the phase transition mechanism, we compare the Gibbs free energy between cubic phase and tetragonal phase by including the configurational entropy. Our results show that the configurational entropy contributes substantially to the stability of the cubic phase at room temperature due to the disordered Mn3+/Mn4+ distribution as well as the orientation of the Jahnâ€"Teller elongation of the Mn3+O6 octahedron in the the spinel phase. Meanwhile, the phase transition temperature is predicted to be 267.8 K, which is comparable to the experimentally observed temperature. These results serve as a good complement to the experimental study, and are beneficial to the improving of the electrochemical performance of LiMn2O4 cathode. [ABSTRACT FROM AUTHOR]

We constructed a methodology for thermostabilizing a G‐protein coupled receptor (GPCR) in the inactive state whose wild‐type (WT) structure is unknown solely by multiple amino‐acid mutations without the ligand binding. It is a combination of our recently developed theory based on statistical thermodynamics and site‐directed saturation mutagenesis, a method often employed in evolutionary molecular engineering. First, the WT structure is predicted using the homology modeling. Second, a key residue is determined by our statistical‐thermodynamics theory using suitably modeled mutant structures. Many of 19 different single mutations for the key residue are expected to produce significantly higher stabilization. Third, we undertake to mutate not only the key residue but also a few more residues whose side chains are close to the side chain of the key residue. The whole mutational space is then efficiently explored by introducing site‐directed saturation mutations, and a gene (mutant) library is constructed using the small‐intelligent and fully automatic single‐tube recombination methods. Each mutant is expressed in Escherichia coli cells, and highly stabilized mutants are sorted out using a fluorescence‐screening technique. The methodology was illustrated for the serotonin 2A receptor, 5‐HT2AR, for stabilizing its inactive state. We could identify a double mutant whose apparent midpoint temperature of thermal denaturation is higher than that of a thermostabilized double mutant previously reported by ~8.9°C and that of the WT by over 15°C. Moreover, it exhibits higher binding affinity for spiperone, an antagonist which was previously proved to stabilize 5‐HT2AR in the inactive state. [ABSTRACT FROM AUTHOR]

The spinel-type LiMn2O4 is a promising candidate as cathode material for rechargeable Li-ion batteries due to its good thermal stability and safety. Experimentally, it is observed that in this compound there occur the structural phase transitions from cubic ( F d 3 ÂŻ m ) to tetragonal (I 41/ amd) phase at slightly below room temperature. To understand the phase transition mechanism, we compare the Gibbs free energy between cubic phase and tetragonal phase by including the configurational entropy. Our results show that the configurational entropy contributes substantially to the stability of the cubic phase at room temperature due to the disordered Mn3+/Mn4+ distribution as well as the orientation of the Jahnâ€"Teller elongation of the Mn3+O6 octahedron in the the spinel phase. Meanwhile, the phase transition temperature is predicted to be 267.8 K, which is comparable to the experimentally observed temperature. These results serve as a good complement to the experimental study, and are beneficial to the improving of the electrochemical performance of LiMn2O4 cathode. [ABSTRACT FROM AUTHOR]

In this note we present that the patch counting entropy can be obtained as a limit and investigate which sequences of compact sets are suitable to define this quantity. We furthermore present a geometric definition of patch counting entropy for Delone sets of infinite local complexity and that the patch counting entropy of a Delone set equals the topological entropy of the corresponding Delone dynamical system. We present our results in the context of (non‐compact) locally compact abelian groups that contain Meyer sets. [ABSTRACT FROM AUTHOR]

Bastnäsites (LnCO 3 (F,OH)) are a group of common rare earth elements (REE)-bearing minerals and are one of the primary global sources of REE. Due to the chemical similarities among REE, bastnӓsites tend to occur as solid solutions instead of end members in REE containing ores. To better understand the processes and the mechanisms of formation of such deposits, it is essential to determine the thermodynamic properties of bastnӓsites, including hydroxylbastnӓsite (LnCO 3 OH) solid solutions. In this work, we performed detailed structural and calorimetric investigations on synthetic hexagonal La–Nd hydroxylbastnӓsite (La 1– x Nd x CO 3 OH, x = 0, 0.25, 0.5, 0.75, 1) solid solutions. X-ray diffraction confirms the crystal structure of the solid solution series in the P 6 ¯ space group, and pair distribution function (PDF) analysis reveals local bonding environments characterized by three different types of 9-coordinated metal-oxygen polyhedra. Unit cell parameters of La 1– x Nd x CO 3 OH exhibit a nearly linear relation with the Nd content x , suggesting a random distribution of La and Nd in the structure. Their standard enthalpies of formation (Δ H° f) were determined by high temperature oxide melt drop solution calorimetry, from which the enthalpies of mixing (Δ H mix) were derived. The Δ H mix can be fitted by a regular solution model with an interaction parameter of 12.58 ± 0.16 kJ/mol, suggesting enthalpic metastability of La 1– x Nd x CO 3 OH relative to the two endmembers. Combining entropy and enthalpy, we further estimated the Gibbs free energies of mixing (Δ G mix) at relevant temperatures, revealing favorable temperatures under which the intermediate La 1– x Nd x CO 3 OH phases can be stabilized. Such entropy-driven stabilization, as is consistent with our geochemical modeling results, may explain the enhancement of thermal stability of the solid solutions in nature. Additionally, the temperature range constrained from this study may be used to estimate the thermal history of REE bastnӓsite deposit. [ABSTRACT FROM AUTHOR]