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Vanadium dioxide (VO2) (M1) exhibits a unique metal–insulator transition (MIT) near room temperature, garnering considerable attention for its applications in bolometer, terahertz/infrared detectors, and microelectronic devices. Here, we explore the potential of epitaxially grown VO2 (M1) thin films for near-infrared (IR) detection by optimizing the growth conditions, followed by structural characterization and device fabrication. Alongside the VO2 (M1) phase, two other oxides from the vanadium oxide family, VO2 (A) and V2O5, were also grown on a c-cut sapphire substrate using a pulsed laser deposition (PLD) system. In-depth analysis using temperature-dependent XRD and Raman spectroscopy confirmed the crystalline structure and the quality of epitaxial thin film formation of VO2 (M1), while also unveiling structural phase transition (SPT) behavior and the critical temperature of transition. At elevated temperatures during electrical measurement, the VO2 (M1) epilayer exhibits a first-order phase transition from the metallic to the insulating state, accompanied by a significant change in resistance exceeding three orders of magnitude unveiling its potential in thermal switches, memory-based devices etc. In depth, electrical analysis on all the grown oxides shows that VO2 (M1) and V2O5 exhibit a higher temperature coefficient of resistance (TCR) (3%/K and 2%/K) and a lower 1/f noise (in the order pA / Hz at 0.1 Hz) as compared to VO2 (A), paving scope for further analysis of these two oxides toward important applications in the domain of thermal sensors. Additionally, VO2 (M1) exhibited good bolometric response (in the order of ms) to IR radiation, proving its candidature for the application in IR detectors as well. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations were conducted using the generalized replica exchange method (gREM) on the 4-cyano-4′-n-alkyl biphenyl (nCB) system with n = 5, 6, 7, and 8, which exhibits a nematic–isotropic (NI) phase transition. Sampling near the phase transition temperature in systems undergoing first-order phase transitions, such as the NI phase transition, is demanding due to the substantial energy gap between the two phases. To address this, gREM, specifically designed for first-order phase transitions, was utilized to enhance sampling near the NI phase transition temperature. Free-energy calculations based on the energy representation (ER) theory were employed to characterize the NI phase transition. ER evaluates the insertion free energy of the nCB molecule for both nematic and isotropic phases, revealing a change in the temperature dependence across the NI phase transition. Further decomposition into energetic and entropic terms quantitatively shows the balance between these contributions at the NI phase transition temperature. [ABSTRACT FROM AUTHOR]

Cerium is regarded as one of the few metals that exhibit a first-order liquid–liquid phase transition (LLPT). However, despite the theoretical attribution of the LLPT to the localized-itinerant transition of f-electrons, there is still a lack of compelling experimental evidence to support this important scientific inquiry. In this study, we investigate the evolution of sound velocity in molten cerium along the isothermal and isobaric paths under static compression. Drawing parallels with the extensively studied γ–α isostructural phase transition, the V-shaped trend of temperature-dependent sound velocity in liquid suggests the existence of LLPT and identifies an associated mechanism predominating liquids' compressibility. [ABSTRACT FROM AUTHOR]

Large magnetocaloric effects can be observed in materials with first-order magneto-structural phase transition. However, materials with large thermal hysteresis show a reduced effect in moderate fields (∼ 2 T) because the external field is insufficient to induce a fully reversible transformation. The hysteresis can be overcome or even exploited by applying a second external stimulus. A multi-stimuli test bench has been built to demonstrate the multicaloric effect in FeRh alloy using a pulsed magnetic field up to 9 T and a uniaxial stress of up to 700 MPa. A cyclic multicaloric effect of ± 2.5 K could be observed for a sequential application of a pulsed field of 3 T and a uniaxial stress of 700 MPa. The interplay among external field strength, thermal hysteresis, and the transition width enables the use of pulsed magnetic fields and allows a decoupling of the applied magnetic field and the heat transfer process in the multi-stimuli cycle. [ABSTRACT FROM AUTHOR]

We investigate the first-order liquid–liquid phase transition in fluid hydrogen, which is accompanied by a nonmetal-to-metal transition. We use a combination of density functional theory for the electrons and molecular dynamics simulations for the ions. By employing the nonlocal Heyd–Scuseria–Ernzerhof exchange-correlation functional, we accurately determine the equation of state and the corresponding coexistence line. Additionally, we calculate the electrical conductivity using the Kubo–Greenwood formula and find jumps in the coexisting region, which is characteristic of a first-order transition. Our new predictions are compared with previous theoretical results and available experimental data. Thereby, we find that the strongly constrained and appropriately normed exchange-correlation functional provides an excellent balance between computational cost and accuracy. [ABSTRACT FROM AUTHOR]

HoCo 2 exhibits a giant magnetocaloric (MC) effect at its first-order magnetostructural phase transition around 77 K, and understanding the thermodynamic nature of this transition in response to external magnetic fields is crucial for its MC applications. In this study, we present a comprehensive investigation of specific heat and magnetization measurements of HoCo 2 under varying magnetic fields. The specific heat measurements qualitatively indicate a transformation from first- to second-order behavior of this phase transition at higher magnetic fields. However, analysis of the power-law dependence of the magnetic entropy change (Δ S M ∝ H n) and the breakdown of universal behavior in the temperature dependence of Δ S M suggest that the first-order nature remains intact, even up to 7 T. This stability of the first-order nature is further manifested through the distinctive non-linear behavior of modified Arrott plots, with a negative slope in the 6–7 T range. [ABSTRACT FROM AUTHOR]

HoCo 2 exhibits a giant magnetocaloric (MC) effect at its first-order magnetostructural phase transition around 77 K, and understanding the thermodynamic nature of this transition in response to external magnetic fields is crucial for its MC applications. In this study, we present a comprehensive investigation of specific heat and magnetization measurements of HoCo 2 under varying magnetic fields. The specific heat measurements qualitatively indicate a transformation from first- to second-order behavior of this phase transition at higher magnetic fields. However, analysis of the power-law dependence of the magnetic entropy change (Δ S M ∝ H n) and the breakdown of universal behavior in the temperature dependence of Δ S M suggest that the first-order nature remains intact, even up to 7 T. This stability of the first-order nature is further manifested through the distinctive non-linear behavior of modified Arrott plots, with a negative slope in the 6–7 T range. [ABSTRACT FROM AUTHOR]

Despite a large amount of work being devoted to study the phase separation in solids, the underlying physical mechanism responsible for such diffusive first-order phase transitions remains difficult to model outside the spinodal regime, i.e., in the nucleation and growth regime. This work presents an alternative of the classical nucleation theory for modeling phase separation in this regime, even for systems far from the solubility limit, i.e., for high degree of meta-stability where the classical nucleation theory does not hold. This method then allows a direct comparison between simulations and experiments always performed in solids with a high degree of meta-stability. [ABSTRACT FROM AUTHOR]

Magnetic refrigeration working based on the magnetocaloric effect can be the perfect replacement of the conventional gas compression-based refrigeration technology and reduces its harmful effects on the environment. The boundary between a first-order and a second-order phase transition would be where the perfect magnetocaloric material would be found. Therefore, establishing the sequence of phase transitions clearly is essential for the characterization of other phase change materials and for applied magnetocaloric research. A quantitative fingerprint of second-order thermomagnetic phase transitions is reported here in Si-substituted high content Mn-based inverse Heusler alloy systems, which are found to be crystallized in cubic structures. The second-order nature of the phase transition has been confirmed from the Arrott plot analysis and a correlation between magnetocaloric effect and local exponent is established. Using the Arrott plot, the critical exponents are evaluated employing different techniques such as modified Arrott plot, Kouvel–Fisher method, and critical isotherm. Their values are found to be in great agreement with each other and follow the mean-field model signifying the presence of long-range ordering in the materials. The high value of isothermal magnetic entropy change and the reversibility justifies the suitability of the reported materials in the practical application as magnetic refrigerants. [ABSTRACT FROM AUTHOR]

Developing phase diagrams for inhomogeneous systems in thermodynamics is difficult, in part, due to the large phase space and the possibility of unstable and metastable solutions arising from first-order phase transitions. Pseudo-arclength continuation (PAC) is a method that allows one to trace out stable and unstable solutions of nonlinear systems. Typically, PAC utilizes the Jacobian in order to implement Newton (or quasi-Newton) steps. In this work, we present a Jacobian-free PAC method that is amenable to the usual workflows in inhomogeneous thermodynamics. We demonstrate our method in systems that have first-order phase transitions, including a novel example of polyelectrolyte complex coacervation in confinement, where multiple surface phase transitions occur and can overlap with one another. [ABSTRACT FROM AUTHOR]

Using commercially available components, a compact laboratory-type prototype has been developed and assembled to demonstrate single and multicaloric effects arising from single and cyclic applications of magnetic fields and uniaxial mechanical loads. Using the example of the LaFe11.4Mn0.3Si1.3H1.6 alloy with a first-order phase transition near room temperature, the possibility of observing magnetocaloric, elastocaloric, and multicaloric effects is demonstrated. It is shown that by selecting protocols for applying combined external influences: magnetic field and mechanical load, it is possible to observe a synergistic effect for adiabatic temperature change, which amounts to 1.17 K (0.31 T and 19 MPa) at a temperature of 291.5 K for the multicaloric effect, which exceeds the corresponding value of |ΔT| = 0.75 K (0.31 T) at a temperature of 291.65 K for the magnetocaloric effect. The proposed approaches and obtained results can be used for the development of new prototypes of multicaloric cooling systems and the optimization of current ones. [ABSTRACT FROM AUTHOR]

Here, we establish an approach to determine temperature-dependent aggregation rates in terms of thermostatistical quantities, which can be obtained directly from flat-histogram and statistical temperature algorithms considering the density of states of the system. Our approach is validated through simulations of an Ising-like model with anisotropically interacting particles at temperatures close to its first-order phase transition. Quantitative comparisons between the numerically obtained forward and reverse rates to approximate analytical expressions corroborate its use as a model-independent approach. [ABSTRACT FROM AUTHOR]

We examine structural and magnetic properties of a series of La–Fe–Si alloys in the region of concentrations where they naturally form two-phase LaFeSi–LaFe13−xSix composites with variable content and connectivity of LaFe13−xSix grains distributed within the LaFeSi matrix. Theoretical calculations confirm that the LaFeSi constituent is magnetically and structurally inert below room temperature and at pressures between −10 and 10 GPa. The LaFe13−xSix constituent, on the other hand, is magnetically and structurally active: it exhibits first-order magnetostructural transformations that, in addition to xSi, can be controlled with temperature, magnetic field, and pressure. In composites where the concentration of the inactive constituent is ∼70 wt. % or greater, the standard, single-step, LaFe13−xSix first-order phase transformation proceeds in two steps separated by over 30 K in a zero magnetic field. Increasing the magnetic field recouples the two steps and restores the single-step phase transformation pathway. We analyze the roles of stresses caused by both thermal expansion mismatch and the first-order magnetic phase transition in LaFe13−xSix to rationalize the observed physical behaviors that emerge as the temperature or/and magnetic field vary. [ABSTRACT FROM AUTHOR]

The task of a first principles theoretical calculation of the rate of gas–liquid nucleation has remained largely incomplete despite the existence of reliable results from unbiased simulation studies at large supersaturation. Although the classical nucleation theory formulated by Becker–Doring–Zeldovich about a century ago provides an elegant, widely used picture of nucleation in a first-order phase transition, the theory finds difficulties in predicting the rate accurately, especially in the case of gas-to-liquid nucleation. Here, we use a multiple-order parameter description to construct the nucleation free energy surface needed to calculate the nucleation rate. A multidimensional non-Markovian (MDNM) rate theory formulation that generalizes Langer's well-known nucleation theory by using the Grote–Hynes MDNM treatment is used to obtain the rate of barrier crossing. We find good agreement of the theory with the rate obtained by direct unbiased molecular dynamics simulations—the latter is feasible at large supersaturation, S. The theory gives an experimentally strong dependence of the rate of nucleation on supersaturation, S. Interestingly, we find a strong influence of the frequency-dependent friction coefficient at the barrier top. This arises from multiple recrossings of the barrier surface. We find that a Markovian theory, such as Langer's formulation, fails to capture the rate quantitatively. In addition, the multidimensional transition state theory expression performs poorly, revealing the underlying role of the friction coefficient. [ABSTRACT FROM AUTHOR]

Ferroelectric transition and polarization characteristics were explored for filled tungsten bronze Ba4Sm2Ti4Nb6O30 ceramics with pinched P–E hysteresis loops. Two dielectric permittivity peaks were observed at around 553 and 486 K on heating and cooling cycles, respectively, with a large thermal hysteresis (∼77 K), indicating the first-order ferroelectric phase transition behavior in the present ceramics. In addition, a low-temperature dielectric relaxation appeared at around 300 K, following the Vogel–Fulcher relationship, which is related to thermal activation related to the polarization in the ab plane. Pinched P–E hysteresis loops were detected in the temperature range of 293–453 K with two pairs of coercive fields, indicating certain polar reversal mechanism, while E1 corresponds to the reversal field needed for all the ferroelectric domains in the system, and E2 is the back switch field from the polar state to the nonpolar state. Therefore, (E1–E2)/2 is the effect coercive field for the polar domain induced by the field transition. Temperature dependence of the coercive fields E1, E2, and (E1–E2)/2 is fitted to the Vopsaroiu model with different activated energies obtained for different temperature ranges, based on which the polarization dynamics of the pinched hysteresis loops are discussed. [ABSTRACT FROM AUTHOR]

The electric field dependence of the electrocaloric effect is investigated in BaTiO 3 and Ba(Zr 0.12 Ti 0.88 )O 3 by a direct method with sub-mK temperature resolution. The field dependence of the caloric temperature change Δ T (E) shows a pronounced change within a few Kelvin around the Curie temperature for the first-order phase transition in BaTiO 3. The transition from a linear field dependence in the ferroelectric phase over a butterfly-shaped to a quadratic field dependence in the paraelectric phase is compared to predictions of Landau–Devonshire theory. The simultaneous measurement of caloric and dielectric properties further allows for the investigation of the polarization dependence Δ T (P) of the electrocaloric effect. We find clear deviations from the predicted quadratic polarization dependence for temperatures close to the Curie temperature. Ba(Zr 0.12 Ti 0.88 )O 3 shows in contrast only a slow and gradual change of the field dependence over a broad temperature range as a consequence of its diffuse phase transition. [ABSTRACT FROM AUTHOR]

Our study is based on the hypothesis that stock exchanges, being nonlinear, open and dissipative systems, are capable of self-organization to the edge of a phase transition. To empirically support the hypothesis, we find segments in hourly stock volume series for 3,000 stocks of publicly traded companies, corresponding to the time of stock exchange's stay to the edge of a phase transition. We provide a theoretical justification of the hypothesis and present a phenomenological model of stock exchange self-organization to the edge of the first-order phase transition and to the edge of the second-order phase transition. In the model, the controlling parameter is entropy as a measure of uncertainty of information about a share of a public company, guided by which stock exchange players make a decision to buy/sell it. The order parameter is determined by the number of buy/sell transactions by stock exchange players of a public company's shares, i.e., stock's volume. By applying statistical tests and the AUC metric, we found the most effective early warning measures from the set of investigated critical deceleration measures, multifractal measures and reconstructed phase space measures. The practical significance of our study is determined by the possibility of early warning of self-organization of stock exchanges to the edge of a phase transition and can be extended with high frequency data in the future research. [ABSTRACT FROM AUTHOR]

This report presents the first results on broadband dielectric spectroscopy insights into ODIC-forming neopentyl glycol (NPG) under compression up to the GPa domain. Particular attention was paid to the strongly discontinuous phase transition: orientationally disordered crystal (ODIC)–solid crystal. The insights cover static, dynamic, and energy-related properties, namely evolutions of the dielectric constant, DC electric conductivity, and dissipation factor. Worth stressing are results regarding the pressure-related Mossotti catastrophe-type behavior of the dielectric constant, the novel approach to non-Barus dynamics, and the discussion on fundamentals of dissipation factor changes in NPG. The results presented in the given report also introduce new experimental evidence and model discussions regarding the nature of ODIC mesophase and discontinuous phase transitions. Notable is the significance of understanding the nature of the colossal barocaloric effect in NPG. [ABSTRACT FROM AUTHOR]

The article in Nature Communications addresses criticisms from Marek Szafrański and Andrzej Katrusiak regarding a study on guanidinium nitrate. The authors refute the criticisms, stating they are biased and lack data support. They discuss the actuating properties of guanidinium nitrate crystals, addressing issues related to crystal quality and experimental methods. The text also includes experimental measurements on the crystals' ferroelectric properties, using a parallel plate capacitor with silver electrodes. The authors stress the significance of evidence-based critiques and open scientific discourse in the research community. [Extracted from the article]

We explore the first-order phase transition in the lattice Schwinger model in the presence of a topological θ-term by means of the variational quantum eigensolver (VQE). Using two different fermion discretizations, Wilson and staggered fermions, we develop parametric ansatz circuits suitable for both discretizations, and compare their performance by simulating classically an ideal VQE optimization in the absence of noise. The states obtained by the classical simulation are then prepared on the IBM's superconducting quantum hardware. Applying state-of-the art error-mitigation methods, we show that the electric field density and particle number, observables which reveal the phase structure of the model, can be reliably obtained from the quantum hardware. To investigate the minimum system sizes required for a continuum extrapolation, we study the continuum limit using matrix product states, and compare our results to continuum mass perturbation theory. We demonstrate that taking the additive mass renormalization into account is vital for enhancing the precision that can be obtained with smaller system sizes. Furthermore, for the observables we investigate we observe excellent agreement in the continuum limit of both fermion discretizations. [ABSTRACT FROM AUTHOR]

This review article provides the basics and discusses some important applications of thermal field theory, namely, the combination of statistical mechanics and relativistic quantum field theory. In the first part, the fundamentals are covered: the density matrix, the corresponding averages, and the treatment of fields of various spin in a medium. The second part is dedicated to the computation of thermal Green's function for scalars, vectors, and fermions with path-integral methods. These functions play a crucial role in thermal field theory as explained here. A more applicative part of the review is dedicated to the production of particles in a medium and to phase transitions in field theory, including the process of vacuum decay in a general theory featuring a first-order phase transition. To understand this review, the reader should have good knowledge of non-statistical quantum field theory. [ABSTRACT FROM AUTHOR]

The results of the study of the temperature dependence of the dielectric permittivity of Cd2P2S6 crystals are presented. It is shown that in the temperature range 80–420 K there are three regions in which hysteresis phenomena are observed. At high temperatures (T > 320 K) there is an activation change of the dielectric losses associated with the increased conductivity of Cd2P2S6 crystals. The transition from heating to cooling leads to a decrease in losses, which is manifested as a hysteresis in the dielectric constant. A jump-like change in dielectric permittivity is found at 228 K in the cooling mode and 265 K in the heating mode, which is due to the first-order phase transition in these crystals. The third hysteresis region appears at low temperatures of 80–90 K. When the temperature is cycled in this interval, the classical hysteresis behavior is observed with a decrease in both amplitude and temperature range with each cycle. The cause of this behavior will be the subject of further investigation. [ABSTRACT FROM AUTHOR]

We investigate the dynamics of the electroweak phase transition within an extended Standard Model framework that includes one real scalar (Φ) and one complex scalar (S), both of which are SM gauge singlets. The global U(1) symmetry is softly broken to a Z 3 symmetry by the S3 term in the scalar potential. After this U(1) symmetry breaking, the imaginary component of the complex scalar (S) acts as a pseudo-Nambu-Goldstone boson (pNGB) dark matter candidate, naturally stabilized by the Z 2 symmetry of the scenario. Specially, the spontaneous breaking of the global U(1) symmetry to a discrete Z 3 subgroup can introduce effective cubic terms in the scalar potential, which facilitates a strong first-order phase transition. We analyze both single-step and multi-step first-order phase transitions, identifying the parameter space that satisfies the dark matter relic density constraints, complies with all relevant experimental constraints, and exhibits a strong first-order electroweak phase transition. The interplay of these criteria significantly restricts the model parameter space, often leading to an underabundant relic density. Moreover, we delve into the gravitational wave signatures associated with this framework, offering valuable insights that complement traditional dark matter direct and indirect detection methods. [ABSTRACT FROM AUTHOR]

Generosity through donation plays a crucial role in reducing inequality and influencing human behavior. However, previous research on donation has overlooked individuals' acceptance of the extent of inequality, which acts as a trigger for donation. To address this gap, this paper systematically explores the impact of donation based on inequality tolerance on the evolution of cooperation in spatial public goods game. Specifically, donation occurs only when an individual's payoff advantage exceeds her inequality tolerance. The results show that donation patterns are crucial for the emergence and stability of cooperation. In the enduring period, the defector-to-cooperator donation pattern helps to form cooperative clusters. In the expanding period, cooperator-to-cooperator, defector-to-defector, and defector-to-cooperator donation patterns create a stable three-layer structure through self-organization, providing a payoff advantage to boundary cooperators. As donation ratio increases, the three-layer structure provides a greater payoff advantage to boundary cooperators, leading to an increase in cooperation. As inequality tolerance increases, changes in donation patterns weaken the three-layer structure, causing cooperation to decrease or disappear through discontinuous phase transitions. Subsequently, all critical points of discontinuous phase transitions are identified by specific spatial configurations. In addition, the influence of donation patterns on the evolution of cooperation is robust, even in heterogeneous small-world networks. This paper offers valuable insights into the dynamics of cooperation evolution and the role of donation in shaping behavior. [ABSTRACT FROM AUTHOR]

The paper presents the results of the development and study of the structural features and properties of nanocomposites and nanohybrids based on a block copolymer of ethylene with propylene and nanoparticles of the natural mineral clinoptilolite dressed with an organosilicon compound — γ-aminopropyltriethoxysilane. To identify the role of the sizing agent in the nature of changes in the physical-mechanical and thermal deformation characteristics of nanohybrids, the influence of filler content on the tensile strength, tensile yield strength, elongation, heat resistance, and melt flow index was studied. It was shown that the use of sizing agents can significantly eliminate the brittle destruction of nanohybrids even at 30.0 wt% clinoptilolite content. At the same time, the fluidity of the melt of samples in highly filled composites was maintained. The use of the thermomechanical research method made it possible to clearly identify a first-order phase transition, including for dressed nanohybrids. A slight increase in the temperature of the first-order phase transition of dressed nanohybrids has been established, which, in all likelihood, can be associated with the formation of interpenetrating networks in the structure. Depending on the content of dressed clinoptilolite and in accordance with the Kolmogorov–Avrami theory, the mechanism and kinetic regularities of crystallization of nanohybrids and nanocomposites were studied. It has been shown that the use of dressed clinoptilolite nanoparticles contributes to the preservation of the disk-shaped growth mechanism of crystalline formations even at 20.0 wt% content in the graft copolymer of a block copolymer of ethylene with propylene with grafted chains of polymethacrylic acid. [ABSTRACT FROM AUTHOR]

In this study, we investigate the magnetocaloric effects (MCE) and critical behavior of Gd-doped La 0. 6 5 Ca 0. 3 5 − x GdxMnO3 (x = 0 , 0. 1 0 , 0. 1 5) polycrystalline materials. Our results reveal excellent MCE in the Gd-doped samples. Under a magnetic field of 7 T, the full-width at half maximum (Δ T FWHM ) increases from 41 K (x = 0. 0 0) to 121 K (x = 0. 1 0) and 112 K (x = 0. 1 5). Additionally, the refrigerant capacity (RC) is enhanced by 149% and 145% at x = 0. 1 0 and x = 0. 1 5 , respectively, compared to the parent phase. We propose that these improvements can be attributed to the introduction of Gd 3 + ions, which possess smaller ionic radii. This reduction in the average A-site ionic radius weakens the double exchange (DE) interactions, resulting in a more continuous phase transition within the system. Supporting this view, we observe a decrease in magnetization strength after doping, a reduction in Curie temperature ( T C) from 250 K (x = 0. 0 0) to 134 K (x = 0. 1 0) and 130 K (x = 0. 1 5) and a transformation from a first-order to a second-order phase transition in the doped samples. To characterize the critical behavior of the phase transition in the doped samples, we employ the K-F method. The obtained critical exponents for x = 0. 1 0 and x = 0. 1 5 are β = 0. 3 8 0 ± 0. 0 0 6 , γ = 1. 3 2 3 ± 0. 0 0 3 , δ = 4. 4 8 2 ± 0. 0 0 5 and β = 0. 4 7 7 ± 0. 0 0 8 , γ = 1. 0 8 3 ± 0. 0 0 4 , δ = 3. 2 7 0 ± 0. 0 0 2 , respectively. Furthermore, the calculation of the n values suggests a transition of the phase transition in the doped samples from short-range ordering to long-range ordering. [ABSTRACT FROM AUTHOR]

The emergence of order from initial disordered movement in self-propelled collective motion is an instance of nonequilibrium phase transition, which is known to be first order in the thermodynamic limit. Here, we introduce a multiplicative scalar noise model of collective motion as a modification of the original Vicsek model, which more closely mimics the particles' behavior. We allow for more individual movement in sparsely populated neighborhoods, the mechanism of which is not incorporated in the original Vicsek model. This is especially important in the low velocity and density regime where the probability of a clear neighborhood is relatively high. The modification, thus, removes the shortcoming of the Vicsek model in predicting continuous phase transition in this regime. The onset of collective motion in the proposed model is numerically studied in detail, indicating a first-order phase transition in both high and low velocity/density regimes for systems with comparatively smaller size which is computationally desirable. [ABSTRACT FROM AUTHOR]

We consider a five-dimensional fully anisotropic holographic model supported by Einstein-dilaton-three-Maxwell action. This type of model within different warp-factors and the coupling function for the Maxwell field providing the nontrivial chemical potential can describe magnetic/inverse magnetic catalysis phenomena expected from lattice results for heavy and light quarks. To reproduce magnetic catalysis phenomena for heavy quarks, we should modify the warp factor and consider additional polynomial terms in warp factor. It is expected that the first-order phase transition will coincide with chiral phase transition and the phase between first-order phase transition line and confinement/deconfinement line can be interpreted as quarkyonic phase. [ABSTRACT FROM AUTHOR]

In the real world, individuals may become infected with an epidemic after multiple exposures to the corresponding virus. This occurs because each individual possesses certain physical defenses and immune capabilities at the time of exposure to the virus. Repeated exposure to the virus can lead to a decline in immune competence, consequently resulting in epidemic infection. The susceptibility of individuals to an epidemic is heterogeneous. We model this characteristic as the individual heterogeneous infection threshold. Then, we propose an individual logarithmic-like infection threshold function on a single-layer complex network to reflect the heterogeneity of individual susceptibility on infecting the virus and the associated epidemic. Next, we introduce a partition theory based on the edge and logarithmic-like infection threshold function to qualitatively analyze the mechanisms of virus infection and epidemic spreading. Finally, simulation results on Erdő–Rényi (ER) and scale-free (SF) networks indicate that increasing both the epidemic infection initial threshold and outbreak threshold, as well as decreasing the virus and epidemic infection probability, can all effectively suppress epidemic spreading and epidemic infection outbreak. With an increase in the epidemic infection outbreak threshold, the increasing pattern of the final epidemic infection scale transitions from a second-order continuous phase transition to a first-order discontinuous phase transition. Additionally, degree distribution heterogeneity also significantly impacts the outbreak and spread of diseases. These findings provide valuable guidance for the formulation of immunization strategies. [ABSTRACT FROM AUTHOR]

The hybrid metal halide [(CH3)3NOH]2CoCl4 exhibits a first-order phase transition at T ∼ 343 K. Its crystal structure and caloric properties respond significantly to moderate pressures (1–1000 bar), demonstrating potential for applications in emerging solid-state refrigeration technologies. [ABSTRACT FROM AUTHOR]

The hybrid metal halide [(CH3)3NOH]2CoCl4 exhibits a first-order phase transition at T ∼ 343 K. Its crystal structure and caloric properties respond significantly to moderate pressures (1–1000 bar), demonstrating potential for applications in emerging solid-state refrigeration technologies. [ABSTRACT FROM AUTHOR]

The article presents the results of studies of the influence of aluminum hydroxide concentration on the crystallization process regularities of nanocomposites based on compatibilized polypropylene random copolymer and aluminum hydroxide (PP-R/PPH-g-MAH/Al(OH)3 ). The isothermal crystallization kinetics of compatibilized polypropylene random copolymer composites containing 1, 3, 5, 10, 20, 30 and 50 wt.% of aluminum hydroxide was determined by the stepwise dilatometry method using the Kolmogorov-Avrami equation. The crystallization behaviors of composites were investigated on an IIRT-1 device converted into a dilatometer, in the process of stepwise cooling of samples under a load of 5.3 kg. In this study, maleic anhydride functionalized homopolypropylene (PPH-g-MAH) was employed as a compatibilizer to enhance the compatibility between the PP-R and Al(OH)3 . Considering the dependence of specific volume and free specific volume on temperature, the first-order phase transition was established, and the glass transition temperature values of the composites were determined. The mechanism of formation and development of crystallization centers in the region of the first-order phase transition was investigated. The obtained values of “n” prove that the mechanism or nature of the growth of crystallization centers changes into three-dimensional spherulitic-two-dimensional disc-shaped-one-dimensional rod-shaped with an increase in the amount of aluminum hydroxide in composite. The study of the temperature dependence of the specific volume for the studied samples showed that the first order phase transition occurs at a temperature of 125°C. It was determined that the second order phase transition temperature (the glass transition temperature determined by the dilatometric method) increases with the increase in the amount of filler. [ABSTRACT FROM AUTHOR]

Dyonic black holes with quasitopological electromagnetism exhibit an intriguing phase diagram with two separated first-order coexistence curves. In this paper, we aim to uncover its influence on the black hole thermodynamical topology. At first, we investigate the phase transition and phase diagram of the dyonic black holes. Comparing with previous study that there is no black hole phase transition region for a middle pressure, we find this region can narrow or disappear by fine tuning the coupling parameter. Instead, two first-order phase transitions can be observed. Importantly, we uncover that such novel phase diagram shall lead to a multiple defect curve phenomenon in black hole topology where each dyonic black hole is treated as one defect in the thermodynamical parameter space. By examining the topology, it is shown that there could be one, three, or five black hole states for given pressure and temperature. For each case, the topological number is calculated. Our results show that the topological number always takes value of + 1 , keeping unchanged even when the multiple defect curves appear. Therefore, our study provides an important ingredient on understanding the black hole thermodynamical topology. [ABSTRACT FROM AUTHOR]

La0.7Ca0.3MnO3 (LCMO) is a prominent semi-metallic ferromagnet known for its strong spin polarization and sharp magnetic transition temperature. This makes it a highly attractive candidate for various applications in spintronic technology, memory devices, and multifunctional systems. The structural and physical properties of LCMO can be significantly altered by adjusting the annealing atmosphere during synthesis. Here, we present an in-depth analysis on the influence of oxygen annealing on the structural characteristics, magnetic behavior, and magnetocaloric properties of LCMO compound. The analysis of X-ray diffraction patterns by using Rietveld refinement method revealed that all the samples formed an orthorhombic structure with the Pnma space group with a decrease in cell volume for samples (S2 and S3) annealed in oxygen atmosphere. The samples S1, S2, and S3 undergo ferromagnetic-paramagnetic phase transitions at 247, 263, and 264 K, respectively. This suggests that the oxygenated annealing induce the oxygen homogeneity in the sample. On the other hand, the field-dependent magnetization measurements and Arrott analysis indicated a first-order ferromagnetic phase transition in all the prepared samples. The maximum change in magnetic entropy was evaluated by using numerical approximation of Maxwells thermodynamic relation. It was noted that the maximum change in magnetic entropy shows monotonic behaviour with oxygen annealing. This ability to adjust magnetization and magnetocaloric effect by altering the annealing atmosphere of LCMO presents a novel approach for developing magnetic refrigerants and gaining insight into fundamental phenomena. [ABSTRACT FROM AUTHOR]

Anti-ferroelectric thin films are renowned for their signature double hysteresis loops and sheds light on the distinguished energy storage capabilities of dielectric capacitors in modern electronic devices. However, anti-ferroelectric capacitors are still facing the dual challenges of low energy density and efficiency to achieve state-of-the-art performance. Their large hysteresis and sharp first-order phase transition usually results in a low energy storage efficiency and easy breakdown, severely obscuring its future application. In this study, we demonstrate that anti-ferroelectric (Pb0.97La0.02)(Zr1−xSnx)O3 epitaxial thin films exhibit enhanced energy storage performance through local structural heterogeneity to moderate the first-order phase transition by calculating the corresponding polarization as a function of switching time for the first time. The films exhibit remarkable enhanced breakdown strength (∼3.47 MV/cm, ∼5 times the value for PbZrO3) and energy storage performance. Our endeavors have culminated in the ingenious formulation of a novel strategy, namely, the postponement of polarization processes, thereby elevating the breakdown strength and total energy storage performance. This landmark achievement has unveiled a fresh vista of investigative opportunities for advancing the energy storage prowess of electric dielectrics. [ABSTRACT FROM AUTHOR]

The phenomenon of load redistribution in complex networks has garnered extensive attention due to its profound impact and widespread occurrence. In recent years, higher-order structures have offered new insights into understanding the structures and dynamic processes of complex networks. However, the influence of these higher-order structures on the dynamics of load redistribution, cascade failures, and recovery processes remains to be fully explored. In this study, we propose the load redistribution model with higher-order structures and recovery strategies of cascade failure based on functional upgrading and reconstruction mechanisms. In the cascading failure process with load redistribution and higher-order recovery strategies, we find that higher-order structures can induce a discontinuous phase transition at the low proportion of load redistribution, and the dynamic process displays a dual character of being robust yet fragile. These findings have been examined in both real and classical modeled networks. Interestingly, the largest connected component exhibits three distinct modes as the attack ratio increases at high densities of higher-order structures and recovery mechanisms. [ABSTRACT FROM AUTHOR]

We study the dependence of the beta-function on the running coupling constant in holographic models supported by the Einstein–dilaton–Maxwell action for light and heavy quarks. The dilaton defines the running coupling of the models. Its dependence on boundary conditions leads to the running coupling dependence on them. However, the behavior of the -function as a function of the running coupling does not depend significantly on the boundary condition. The corresponding -functions are negative and monotonically decreasing functions, and have jumps at first-order phase transitions for both light and heavy quarks. In addition, we compare our holographic results for the -function as a function of the running coupling with perturbative results obtained within -loop calculations. [ABSTRACT FROM AUTHOR]

FeRh undergoes a first-order phase transition from the antiferromagnetic (AFM) to ferromagnetic (FM) state at ∼370 K, which is highly sensitive to strain and compositional changes. In this study, we investigate the magnetic and electronic properties of Co-doped FeRh films fabricated using a co-sputtering technique, to address how the magnetic transition behavior is influenced by the doping in FeRh films. By adjusting Co sputtering gun currents (=0, 5, 8, and 10 mA), we achieve Co doping levels from 1 to 2 at. %, where initial Co atoms (for 5 and 8 mA) substitute Rh sites, while doped Co levels (for 10 mA) begin to occupy Fe sites with unchanged Co doping level of 2 at. %. We find that Co substitution significantly lowers the transition temperature, attributed to an enhancement of the FM phase due to the contribution of magnetic Co doping. Furthermore, the Co doping leads to a remarkable increment in the magnetoresistance ratio during the transition, reaching up to 190% for only 2 at. % Co doping, while keeping the magnetization change. The Hall effect measurements indicate a slight reduction in carrier density with Co doping, maintaining changes in carrier type across the phase transition. These results highlight the tunable magnetic phase transition and resistance changes in Co-doped FeRh films. This study provides valuable insights into the complex physics underlying the Co doping in FeRh films, emphasizing their scientific value in understanding the mechanism of the AFM–FM transitions in achieving high magnetoresistance. [ABSTRACT FROM AUTHOR]

We analyze Hayward black holes (BHs) with a negative cosmological constant surrounded by a cloud of strings, which we designate Hayward–Letelier AdS BHs. These solutions can be obtained by coupling the Einstein equations with nonlinear electrodynamics and the energy–momentum tensor of clouds of strings. We show that these solutions are no longer regular and have a curvature singularity at the center. In turn, we analyze the thermodynamics associated with these BHs by establishing the form of the Smarr formula and the first law of thermodynamics. We derive the expressions for the thermodynamic quantities such as pressure, temperature, heat capacity, Gibbs free energy, and isothermal compressibility. We explore the phase structure of these solutions by analyzing the behavior of the heat capacity and Gibbs free energy. These solutions exhibit a first-order phase transition, similar to van der Waals fluids. We also check the behavior of the thermodynamic quantities near the critical points and calculate the values of the critical exponents. This illustrates a robust analogy between our solutions and van der Waals fluids. [ABSTRACT FROM AUTHOR]

We report a large cryogenic magnetocaloric effect stemming from an unconventional borderline first-order magnetic phase transition with negligibly small thermomagnetic hysteresis in a rare-earth-based intermetallic compound PrNdIn. The sample exhibits maximum magnetic field-induced entropy change as large as −10 J/Kg K (for 20 kOe magnetic field change) near the boiling point of oxygen. Magnetocaloric properties of PrNdIn are comparable to those of other known potential magnetocaloric materials with operating temperatures ranging between 50 and 125 K. The magnetic properties of the present sample are qualitatively reminiscent of those of the binary Pr2In and Nd2In, including the emergence of a second low-temperature anomaly in the temperature dependence of magnetization. [ABSTRACT FROM AUTHOR]

Reported herein is a comparative study of the recently uncovered resistive switching related to the M1→T (Insulator-Insulator) transition and that of the well-known, T→M2 (Insulator-Insulator) one, in Al-doped VO2 single crystals. Two crystals from the same batch were investigated by low current R(T), and pulse and DC I-V measurements, their results emphasizing the contrast between the two phase-transitions. Hysteresis, regarded as the hallmark of a first-order phase transition, is exhibited in both R(T) and DC I-V measurements by the T→M2 transition but only in DC I-V measurements (if detected) by the M1→T transition. The contrast between the two phase-transitions is exhibited also by their specific marks on the pulse I-V measurements. The investigation of the two transitions in two crystals of similar composition revealed the effect of the proximity of their transition temperatures on their quality. [ABSTRACT FROM AUTHOR]

During the cosmic evolution process, as the temperature of a cosmological boson gas falls below a certain threshold, a Bose–Einstein condensation process can occur at various points throughout the cosmic history of the Universe. In this model, dark matter, conceptualized as a non-relativistic, Newtonian gravitational condensate is governed by the Gross–Pitaevskii–Poisson system. In our present study, we investigate the Bose–Einstein condensation process of bosonic DM by treating it as an approximate first-order phase transition within a modified cosmological framework, known as Tsallis cosmology. We examine the evolution of relevant physical quantities characterizing the evolution dynamics of the Universe, including energy density, temperature, redshift, scale factor, Hubble parameter, and dimensionless deceleration parameter before, during, and following the Bose–Einstein condensation phase transition takes place. Additionally, we especially investigate the specific era of the evolution of the Universe characterized by a mixture of normal and condensate phases of dark matter. We analyze the behavior of temporal evolution of an important time-dependent parameter, called the condensate dark matter fraction throughout the condensation process and find the time duration of condensation of dark matter in the Tsallis cosmological model. We see that the presence of Bose–Einstein condensate dark matter in the framework of Tsallis-modified cosmology significantly alters the cosmological evolution of the Universe as compared to the standard model of cosmology. We also find for a typical value of Tsallis non-extensive parameter β = 0.35 , the model could explain an accelerated Universe without invoking any additional energy component and solve the age problem of our Universe. [ABSTRACT FROM AUTHOR]

Motivated by the well-known fractal packing of chromatin, we study the Rouse-type dynamics of elastic fractal networks with embedded, stochastically driven, active force monopoles and force dipoles that are temporally correlated. We compute, analytically—using a general theoretical framework—and via Langevin dynamics simulations, the mean square displacement (MSD) of a network bead. Following a short-time superdiffusive behavior, force monopoles yield anomalous subdiffusion with an exponent identical to that of the thermal system. In contrast, force dipoles do not induce subdiffusion, and the early superdiffusive MSD crosses over to a relatively small, system-size-independent saturation value. In addition, we find that force dipoles may lead to "crawling" rotational motion of the whole network, reminiscent of that found for triangular micro-swimmers and consistent with general theories of the rotation of deformable bodies. Moreover, force dipoles lead to network collapse beyond a critical force strength, which persists with increasing system size, signifying a true first-order dynamical phase transition. We apply our results to the motion of chromosomal loci in bacteria and yeast cells' chromatin, where anomalous sub-diffusion, MSD ∼ t ν with ν ≃ 0.4 , was found in both normal and cells depleted of adenosine triphosphate (ATP), albeit with different apparent diffusion coefficients. We show that the combination of thermal, monopolar, and dipolar forces in chromatin is typically dominated by the active monopolar and thermal forces, explaining the observed normal cells vs the ATP-depleted cells behavior. [ABSTRACT FROM AUTHOR]

Isothermal electrocaloric (EC) heat is a key—but rarely reported—parameter for cooling applications. Here, we employ calorimetry with large-area Peltiers (10 × 10 mm2) to study a multilayer capacitor (MLC) of well-ordered PbSc0.5Ta0.5O3 (PST) with a first-order ferroelectric phase transition. Our direct measurements of isothermal EC heat are consistent with complementary EC measurements of similar MLCs that display large EC effects, i.e., indirect EC measurements and direct measurements of adiabatic EC temperature change [Nair et al., Nature 575, 468 (2019)]. Using a field of 7.9 V μm−1, the EC heat associated with the electrically active PST peaks at 11 MJ m−3 near 300 K. At higher temperatures, as one approaches the critical point, the transition is seen to become less first order. Separately, we find that the inactive PST compromises quasi-direct EC measurements. In the future, isothermal EC heat should be directly measured as a matter of routine. [ABSTRACT FROM AUTHOR]

Kagome metal ScV6Sn6 has been a subject of interest due to the emergence of a first-order structural phase transition with intriguing charge density wave behavior below the transition temperature Tc ∼ 92 K. To explore the thermoelectric properties and provide experimental insights into the nature of the phase transition, we have carried out a combined study by means of the electrical resistivity, Seebeck coefficient, and thermal conductivity measurements on single crystalline ScV6Sn6. Pronounced features near Tc have been characterized by all measured physical quantities. In particular, the Seebeck coefficient exhibits a marked reduction as lowering temperature across Tc, attributed to an imbalance of the contribution from different type of carriers induced by the structural phase transition. From the examination of the electronic and lattice thermal conductivities, we obtained a confirmation that the observed enhancement at Tc is essentially caused by the change of the lattice thermal conductivity, demonstrating the primary importance of lattice distortions for the heat transport of ScV6Sn6. In addition, the lattice thermal conductivity above Tc was found to increase monotonically with temperature. We associated the peculiar phenomenon with lattice fluctuations, highlighting the essence of structural instability in the kagome lattice ScV6Sn6. These results add to the knowledge about the thermal transport properties in kagome materials with a hexagonal HfFe6Ge6-type structure. [ABSTRACT FROM AUTHOR]

Kagome metal ScV6Sn6 has been a subject of interest due to the emergence of a first-order structural phase transition with intriguing charge density wave behavior below the transition temperature Tc ∼ 92 K. To explore the thermoelectric properties and provide experimental insights into the nature of the phase transition, we have carried out a combined study by means of the electrical resistivity, Seebeck coefficient, and thermal conductivity measurements on single crystalline ScV6Sn6. Pronounced features near Tc have been characterized by all measured physical quantities. In particular, the Seebeck coefficient exhibits a marked reduction as lowering temperature across Tc, attributed to an imbalance of the contribution from different type of carriers induced by the structural phase transition. From the examination of the electronic and lattice thermal conductivities, we obtained a confirmation that the observed enhancement at Tc is essentially caused by the change of the lattice thermal conductivity, demonstrating the primary importance of lattice distortions for the heat transport of ScV6Sn6. In addition, the lattice thermal conductivity above Tc was found to increase monotonically with temperature. We associated the peculiar phenomenon with lattice fluctuations, highlighting the essence of structural instability in the kagome lattice ScV6Sn6. These results add to the knowledge about the thermal transport properties in kagome materials with a hexagonal HfFe6Ge6-type structure. [ABSTRACT FROM AUTHOR]

The influence of ionizing irradiation on the thermochromic properties of [NH2(C2H5)2]2CuCl4 (DEACC) microcrystals incorporated into a polystyrene matrix was investigated. This composite was found to possess thermochromic properties very similar to those in a bulk crystal although its thermochromic phase transition was shifted toward higher temperatures due to the tensions arising within the interface between the polystyrene matrix and the microcrystal. The similar doses of ionizing radiation cause much more pronounced changes in the thermochromic properties of the microcrystals in comparison with a bulk crystal. The main impact consists in the considerable shift of the phase transition temperature derived from the D(T) hysteresis loops toward lower values that were explained by the breaking of the chemical bonds between the polymer matrix and the microcrystals and the corresponding diminishing of the surface strains. The transformation of the discontinuous phase transition into the continuous one under the influence of irradiation was also discussed. [ABSTRACT FROM AUTHOR]

The study investigates the absorption spectra of [NH2(C2H5)2]2CuCl4 (DEACC) microcrystals incorporated into a polystyrene matrix. It further explores the influence of low-energy X-ray radiation on the thermochromic properties of this microcomposite. This composite, with an average microcrystal size of 200 µm, was found to possess thermochromic properties similar to those of the bulk crystal, although its discontinuous thermochromic phase transition is shifted to higher temperatures in comparison wi- th a single crystal. Such a shift is explained by surface strains that occur at the interface between the polystyrene matrix and the microcrystal. Ionizing radiation causes much more noticeable changes in the thermochromic properties of microcomposites compared to a single crystal when subjected to equivalent doses of irradiation. This influence consists in the non-trivial dependence of the thermochromic phase transition temperature obtained from the hysteresis loops D(T) on the irradiation dose. At relatively small doses of X-radiation, the phase transition temperature increases due to a mechanism similar to that of a single crystal. Specifically, this mechanism involves the breaking and rearrangement of hydrogen bonds facilitated by anionic tetrahedral complexes, resulting in their reconfiguration into a planar-square shape. Upon reaching certain critical values of the radiation dose, the radiation-induced changes become irreversible. They are primarily caused by the breaking of chemical bonds at the interface between the matrix and the microcrystal, leading to a decrease in the temperature of the thermochromic phase transi- tion. The obtained material is non-hygroscopic, mechanically stable and technological. The very simple production technology of the composites makes them suitable for creating cheap individual ionizing X-ray dose sensors. [ABSTRACT FROM AUTHOR]

Phase transitions and critical phenomena are among the most intriguing phenomena in nature and society. They are classified into first-order phase transitions (FOPTs) and continuous ones. While the latter shows marvelous phenomena of scaling and universality, whether the former behaves similarly is a long-standing controversial issue. Here we definitely demonstrate complete universal scaling in field driven FOPTs for Langevin equations in both zero and two spatial dimensions by rescaling all parameters and subtracting nonuniversal contributions with singular dimensions from an effective temperature and a special field according to an effective theory. This offers a perspective different from the usual nucleation and growth but conforming to continuous phase transitions to study FOPTs. [ABSTRACT FROM AUTHOR]