Phase Transition Hysteresis Research Articles

Regulations of Bulk and Interfacial Chemistry of Mn-Based Cathode Materials for Sodium Ion Batteries

Sodium ion batteries (SIBs) show the great potential to achieve large-scale energy storage due to their low cost and good safety as well as abundant resources of sodium. Among the cathode materials for SIBs, manganese-based layered oxides with adjustable structure have been attached great interest for the high energy density and low-cost SIBs. . Particularly, P2-type Mn-based materials exhibit anionic redox during charge and discharge processes, which can not only elevate the battery potential but also provide extra capacity, drastically boosting the energy density of the batteries. However, the irreversible phase transition, Jahn-Teller effect of manganese and interphase degradation at high charge cutoff voltage during anionic redox largely affect the cyclic stability of the cathodes. Therefore, it is essential to develop effective strategies to regulate the structural and interfacial chemistry for suppressing the phase transition and voltage hysteresis as well as increasing the cycle life of cathode materials. In this work, various electrochemical inert/active elements have been introduced into Mn-based P2 type cathode materials for regulating the electronic structure of the cathodes to promote more anionic redox and improve the structural stability. In addition, a new type of ionic liquid is introduced to build a stable interphase and improve the high voltage stability of the cathode material. Multi-model synchrotron-based X-ray characterization techniques combined with first-principles calculation are used to reveal the effectiveness of different strategies on the electrochemical properties of SIBs. The results provide valuable information for the development of high-performance cathode materials. Acknowledgement This work at Shanghai Jiao Tong University was financially supported by the National Natural Science Foundation of China (No. 22209106).

Structural phase transition, relaxor behavior, and ultra-low strain hysteresis in BaTiO3 ceramics modified by BiYO3

In this study, the structural properties, phase transition, relaxor behavior, and strain properties of (1−x)BaTiO3‒xBiYO3 (x= 0.02‒0.15 mol) ceramics were investigated. The room temperature x-ray diffraction and Raman spectroscopy results reveal that (1−x)BaTiO3‒xBiYO3 ceramics undergo phase transition from tetragonal to pseudo-cubic structure with x increasing. The curves of dielectric constant and loss tangent as a function of temperature and frequency show that the dielectric constant was changing from being dependent on temperature to being independent of it upon increasing BiYO3 amount, which is induced obvious dielectric relaxation behavior. Slimmer polarization–electric field (P–E) loops and lower remnant polarization (Pr ) were observed for samples with x ⩾ 0.08. The transition between the ferroelectric and relaxor states leads to the narrow strain–electric field (S–E) loops, which exhibit a high electric field-induced strain of 0.192% and an ultra-low strain hysteresis of 10.4% at an electric field of 70 kV cm−1 for x= 0.04. This excellent performance indicates that 0.96BaTiO3‒0.04BiYO3 ceramic may be promising lead-free materials for high-precision displacement actuators applications.

Effects of non-equilibrium phase behavior in nanopores on multi-component transport during CO2 injection into shale oil reservoir

Injecting CO2 into shale oil reservoirs is one of the most effective methods for enhancing oil recovery (EOR) while simultaneously facilitating CO2 capture, utilization, and storage (CCUS). However, it is not always that gas dissolution or condensate evaporation reaches equilibrium instantaneously during the CO2 injection process. In cases where equilibrium is not attained instantaneously, conventional vapor-liquid equilibrium models will have certain limitations in characterizing phase transition hysteresis. These limitations will affect the accuracy of simulating multi-component transport in porous media. In this paper, a robust and generic vapor-liquid non-equilibrium thermodynamic model considering nano-confinement effects (NC) was established by introducing component mass transfer rates proportional to the chemical potential difference. The established model was then used to modify the fully-compositional, projection-based embedded discrete fracture model (pEDFM). Furthermore, C++ hybrid programming and the Graphics Processing Unit (GPU) parallel method were both used to accelerate both the nonlinear and linear solvers. By comparing with results from MATLAB Reservoir Simulation Tools (MRST), Eclipse, and tNavigator, the accuracy and advantages of our solver were demonstrated. The results show that if the underground fluid undergoes a phase transition from a vapor-liquid two-phase state to a single-phase state, non-equilibrium thermodynamic effects need to be considered, and the simulation results show a larger two-phase zone, higher bottom hole pressure, and lower cumulative liquid production. But the nano-confinement effects will weaken the non-equilibrium thermodynamic effects.

Mechanisms of rapid magnetocaloric enhancement of La–Fe–Co–Si alloy by high-temperature hot compression with large deformation

In this study, the microstructure, phase composition, magnetic transition, and magnetocaloric effect of the LaFe10.6Co0.9Si1.5 alloy hot compressed at high temperatures over 1173 K with a strain rate 0.005 s−1 and reduction ratio 50%–70 % are studied. No La(Fe, Si, Co)13 phase is formed until the hot-compression temperature is elevated to 1273 K and the reduction ratio is increased to 70 %. As a result, 86.8 ± 2 wt% 1:13 phases are rapidly obtained in the LaFe10.6Co0.9Si1.5 ingot. The whole process can be completed within only 10 min and no post-annealing process is needed. This fast formation of the La(Fe, Si, Co)13 phases is possibly induced by the directional atomic diffusion, accelerated atomic diffusion, and the stability of the La(Fe, Si, Co)13 phase and structural relaxation caused by the sufficiently restored elastic energy during the hot compression. The LaFe10.6Co0.9Si1.5 ingot hot compressed at 1273 K with a reduction ratio 70 % at a strain rate 0.005/s exhibits a second-order phase transition and negligible magnetic hysteresis. A large magnetic entropy change of 4.4 J/kg.K and a wide working temperature range of 57 K under 2 T are acquired near room temperature. This study proposes a new efficient hot compression route for processing the La–Fe–Co–Si alloy and enhancing the magnetocaloric effect.

Rich oxygen vacancies mediated metal-insulator transition materials toward ultrasensitive sensing and energy conversion

Regulating structural phase transitions of metal insulator transition (MIT) correlated materials is an ideal approach to modulate their properties. However, due to phase transition hysteresis, ultrasensitive electron transition is difficult to achieve. Here, we develop a convenient method via Fe ions surface doping-induced oxygen vacancies (OVs) at the Ti3O5 surface to enable ultrasensitive electronic transitions. The Fe doping promotes the formation of free electrons, which is attributed to the reduced bandwidth, making it relatively easy for valence band electrons to leap to the conduction band. The formation of OVs increase the electron concentration and enhance the electronic conductivity (2.49×10−4 S/cm) at low temperatures, resulting in an ultrasensitive sensing over a wide temperature range before metal insulator transition. This unique property facilitates its application in fire warning with ultrasensitive sensing (response time 0.63 s, and response temperature 150 °C) and good durability. Moreover, the as-obtained MIT correlated material with rich-OVs structure exhibits excellent oxygen sensing and photothermal conversion properties. These results offer a novel design for MIT correlated materials and provide an innovative insight for modulating their multifunctional properties.

Texture and phase transition hysteresis in epitaxially integrated VO2 films on TiN/Si(100)

Vanadium oxide (VO2), which exhibits a metal-to-insulator (MIT) transition at 68∘C, has been of immense technological interest for many applications such as sensor, electro-optic, and memory devices. In this work, we demonstrate the epitaxial integration of VO2 onto Si(100) via a TiN buffer layer, which is compatible with complementary metal–oxide–semiconductor (CMOS) technology. Our study revealed that the growth of epitaxial VO2 on TiN was mediated by a thin layer of epitaxial TiO2. The orientation relationship between various layers was established to be (011)V O2M∥ (110)TiO2∥ (100)TiN∥ (100)Si and [100]V O2M∥ [001]TiO2∥ [011]TiN∥ [011]Si. Through pole figures, reciprocal space maps (RSM), and transmission electron microscopy (TEM), we confirmed the presence of tilted rotational domains. We quantified the degree of misorientation in various VO2 films by introducing a relevant parameter, η, determined by analyzing the (011) pole figures. We found a correlation indicating that the thermal hysteresis of the phase transition, determined from in-situ temperature-dependent XRD, decreases with the degree of misorientation. This decrease in misorientation suggests the presence of more geometrically compatible grain boundaries, leading to a decrease in thermal hysteresis.

Controllable preparation of VO2@m-SiO2 and its light transmittance and thermal insulation properties of PVB composite films

In this study, a hybrid approach using the Stöber and solvent extraction techniques was employed to synthesize mesoporous silicon-coated VO2 nanomaterials (VO2@m-SiO2, VmS) with controllable pore sizes and shell thicknesses. This synthesis was aimed at elucidating the influence of mesoporous silicon coatings on the thermochromic effect and optical properties of VO2. Experimental findings reveal that the mesoporous silica architecture markedly improve the phase-transition hysteresis of VO2 while mitigating the Mie effects attributable to particle coarsening, under the appropriate shell thickness. Furthermore, concomitant with the enlargement of the mesoporous aperture, the Tlum and ΔTsol of the VmS/PVB films also exhibit upward trends. Tlum reaches 73.33% and 62.24% in VmS3/PVB and VmS5/PVB, peak ΔTsol reaches 5.16% in VmS5/PVB. The facile synthesis procedure of VmS, in conjunction with its superior performance across phase transition, optics, and thermal insulation metrics, offers a viable pathway for industrial-scale deployment of VO2(M) in smart window applications.

Low pressure reversibly driving colossal barocaloric effect in two-dimensional vdW alkylammonium halides

Plastic crystals as barocaloric materials exhibit the large entropy change rivalling freon, however, the limited pressure-sensitivity and large hysteresis of phase transition hinder the colossal barocaloric effect accomplished reversibly at low pressure. Here we report reversible colossal barocaloric effect at low pressure in two-dimensional van-der-Waals alkylammonium halides. Via introducing long carbon chains in ammonium halide plastic crystals, two-dimensional structure forms in (CH3–(CH2)n-1)2NH2X (X: halogen element) with weak interlayer van-der-Waals force, which dictates interlayer expansion as large as 13% and consequently volume change as much as 12% during phase transition. Such anisotropic expansion provides sufficient space for carbon chains to undergo dramatic conformation disordering, which induces colossal entropy change with large pressure-sensitivity and small hysteresis. The record reversible colossal barocaloric effect with entropy change ΔSr ~ 400 J kg−1 K−1 at 0.08 GPa and adiabatic temperature change ΔTr ~ 11 K at 0.1 GPa highlights the design of novel barocaloric materials by engineering the dimensionality of plastic crystals.

Негативное влияние гистерезисных явлений на процесс разработки месторождений нефти и газа

It is known that irreversibilities of hysteresis nature of global or local scale, lead to the necessity to revise the methods of solving the main problems of hydrodynamic modelling and analysis of dynamic systems, as they can radically affect the traditional conclusions and practical recommendations. It is assumed that in the steady-state mode of motion or filtration, phase displacements make all sorts of oscillations in the vicinity of the unstable position, due primarily to irreversible hysteresis phenomena and jumps arising from the instability of the front of oil displacement by water, the manifestation of capillary effects, hysteresis of phase transitions, irreversibility of deformations under excessive load at large pressure drops, including hydraulic fracturing. With this purpose in the theory of catastrophes the dynamic models of growth are investigated and control parameters are selected with the calculation and the possibility to predict the expected local irreversibilities and instabilities before the onset of bifurcation. Hysteresis behaviour in the filtration process is generated by lithological differences of geofluidodynamic medium and its geological and physical characteristics and properties of saturating fluids. And as a rule, it is provoked by not always adequate, excessive external load on the tested medium. The proposed solutions are part of a new concept of unsteady waterflooding, which provides for early prediction and taking measures in case of instability of the displacement front and, as a consequence, water breakthrough into production wells. It is of great interest to prevent the consequences of these negative effects on the quantitative components of technological and economic indicators, in the case of oil field development we are talking about the final recovery factor of oil, gas and condensate. System optimisation of oil field development is designed for a certain technological and economic effect, including additional oil production, effective mobilisation and saving of injected and withdrawn water and gas.

A coupled phase-field and crystal plasticity model for understanding shock-induced phase transition of iron

In the current work, we propose a chemical-potential-based phase-field model coupled with dynamic crystal plasticity based on a unified energy framework with the aim of understanding the shock-induced α–ϵ–α phase transition (PT) of iron. The plasticity is coupled with the PT through controlling the shear strain energy and the entropy rise during the dynamic deformation. In contrast with previous models, the PT pressure in this model is not a constant but obeys the Gaussian distribution with the applied stress, which is in accordance with the hysteresis effect observed in quasi-static experiments. Moreover, the contribution of multivariants to PT can be distinguished based on reaction-pathway theory. The proposed model quantitatively reproduces the split of the three-wave structure and the “loop” features of the plasticity wave and the phase transition wave, which agree well with the shock loading experiments of polycrystalline and monocrystalline iron, and cannot be well captured by previous models. Furthermore, many new insights in shock wave physics are gained. PT kinetics is found to be influenced by plasticity via the hysteresis effect and the newly generated stress wave induced by the dynamic deformation. First, the rarefaction wave induced by plastic deformation, as well as that by the growth of the child phase, behind the shock front reduces the PT plateau in the wave profile. Second, the plasticity controls the PT driving force and influences the PT hysteresis effect behind the shock front. As yield stress increases, less strain energy is plastically dissipated, and more strain energy drives the PT behind the shock front more efficiently, which results in a sharper slope of the P2 wave.

An Interesting Functional Phase Change Material VO2: Response to Multivariate Control and Extensive Applications in Optics and Electronics

AbstractUnder physical conditions such as TC = 68 °C, Vanadium dioxide (VO2) undergoes a reversible transformation from a monoclinic phase to a tetragonal rutile phase. This transformation is accompanied by a series of changes in physical properties, including transmittance, conductivity, and refractive index, which make it an excellent functional material. Based on this, VO2 has been extensively researched and applied in the fields of electronics and optics, yielding remarkable results and making it a hot research material. This paper reviews the phase transition mechanisms and optical/electrical properties of VO2, as well as its phase transition hysteresis. From the application perspective, this paper summarizes the modulation content under various external excitations and the element doping effects. Finally, this paper summarizes the classic VO2‐based devices, and points out the development direction and potential of VO2 in optics and electronics. This review provides a systematic summary of VO2, which is useful for its practical applications.

Thermal hysteresis of mesoscopic phase transitions in fluid metals: From tantalum to aluminum and gold with their critical points and non-mean-field global diagrams

The light soft metal – Al-IIIB in Periodic Table and the heavy soft metal – Au-IB were analyzed within the predictive model of fluctuation–thermodynamics (FT). The similar extrapolative approach was applied for re-establishing of the global phase diagram and non-mean-field criticality of the refractory heavy and rigid tantalum Ta-VA earlier. The revealed then correspondence between the onset point of nano-droplets at atmospheric pressure and the point of instability, observable at much higher pressures by the fast dynamic measurements, found its confirmation for the considered metals as well. It may indicate the universality of the mentioned “dew”-point for any elements and compounds. The mesoscopic nanoscaled time- and length- simultaneous consideration matters especially for all metallic vapors at sub-atmospheric pressures and temperatures beneath the normal boiling one. The FT-predicted critical points of Al and Au are consistent with the available low-temperature thermostatic and rapid dynamic experimental data.

Phase transition hysteresis at the antiferroelectric–ferroelectric boundary in PZT

Phase transition hysteresis at the antiferroelectric–ferroelectric boundary in PZT

Insight into Eu3+-Doped Phase-Change K3Lu(PO4)2 Phosphate toward Data Encryption.

Adjusting the local coordination environment of lanthanide luminescent ions can modulate their crystal-field splittings and broaden their applications in the relevant optical fields. Here, we introduced Eu3+ ions into the phase-change K3Lu(PO4)2 phosphate and found that the temperature-induced reversible phase transitions of K3Lu(PO4)2 (phase I ⇆ phase II and phase II ⇆ phase III, below room temperature) give rise to an obvious photoluminescence (PL) difference of Eu3+ ions. The Eu3+ emission mainly focused on the 5D0 → 7F1 transition in phase III but manifested comparable 5D0 → 7F1,2 transitions in the two low-temperature phases. On this basis, the change of Eu3+-doped concentration led to the phase evolution in Eu3+:K3Lu(PO4)2, which could stabilize two types of low-temperature polymorphs to the specific temperature by controlling the doping content. Finally, we proposed a feasible information encryption strategy based on the PL modulation of Eu3+:K3Lu(PO4)2 phosphors, which was caused by the temperature hysteresis of the relevant phase transition, exhibiting good stability and reproducibility. Our findings pave an avenue for exploring the optical application of lanthanide-based luminescent materials by introducing phase-change hosts.

Nano-infrared imaging of metal insulator transition in few-layer 1T-TaS2

Abstract Among the family of transition metal dichalcogenides, 1T-TaS2 stands out for several peculiar physical properties including a rich charge density wave phase diagram, quantum spin liquid candidacy and low temperature Mott insulator phase. As 1T-TaS2 is thinned down to the few-layer limit, interesting physics emerges in this quasi 2D material. Here, using scanning near-field optical microscopy, we perform a spatial- and temperature-dependent study on the phase transitions of a few-layer thick microcrystal of 1T-TaS2. We investigate encapsulated air-sensitive 1T-TaS2 prepared under inert conditions down to cryogenic temperatures. We find an abrupt metal-to-insulator transition in this few-layer limit. Our results provide new insight in contrast to previous transport studies on thin 1T-TaS2 where the resistivity jump became undetectable, and to spatially resolved studies on non-encapsulated samples which found a gradual, spatially inhomogeneous transition. A statistical analysis suggests bimodal high and low temperature phases, and that the characteristic phase transition hysteresis is preserved down to a few-layer limit.

Thermal arrest analysis of the reverse martensitic transformation in a Ni55Fe19Ga26 Heusler alloy obtained by melt-spinning

Ni55Fe19Ga26 ribbons obtained by melt-spinning technique exhibit a martensitic transformation from L21 cubic austenite phase to 14 M martensite phase above room temperature. We have taken advantage of the existence of thermal hysteresis of the martensitic phase transition (~ 11 K) to analyze the effect of isothermal treatments on the reverse martensitic transformation, which has been analyzed by means of interrupted heating using differential scanning calorimetry. The experimental findings clearly indicate a time-depending effect in the martensitic transformation at temperatures between the austenite start and finish temperatures. Moreover, it has been observed that two successive martensitic transformations take place after the isothermal arrest was performed.

Colossal barocaloric effects with ultralow hysteresis in two-dimensional metal–halide perovskites

Pressure-induced thermal changes in solids—barocaloric effects—can be used to drive cooling cycles that offer a promising alternative to traditional vapor-compression technologies. Efficient barocaloric cooling requires materials that undergo reversible phase transitions with large entropy changes, high sensitivity to hydrostatic pressure, and minimal hysteresis, the combination of which has been challenging to achieve in existing barocaloric materials. Here, we report a new mechanism for achieving colossal barocaloric effects that leverages the large volume and conformational entropy changes of hydrocarbon order–disorder transitions within the organic bilayers of select two-dimensional metal–halide perovskites. Significantly, we show how the confined nature of these order–disorder phase transitions and the synthetic tunability of layered perovskites can be leveraged to reduce phase transition hysteresis through careful control over the inorganic–organic interface. The combination of ultralow hysteresis and high pressure sensitivity leads to colossal reversible isothermal entropy changes (>200 J kg−1 K−1) at record-low pressures (<300 bar).

Study on Influencing Factors of Phase Transition Hysteresis in the Phase Change Energy Storage

Phase change energy storage is a new type of energy storage technology that can improve energy utilization and achieve high efficiency and energy savings. Phase change hysteresis affects the utilization effect of phase change energy storage, and the influencing factors are unknown. In this paper, a low-temperature eutectic phase change material, CaCl2·6H2O-MgCl2·6H2O, was selected as the research object, combined with the mechanism of phase change hysteresis characteristics, using a temperature acquisition instrument to draw the step cooling curve. A differential scanning calorimeter was used to measure the DSC (differential scanning calorimetry) curve, and the hysteresis characteristics of phase transformation were studied by factors, such as heat storage temperature, cooling temperature, and cooling rate. The experimental results show that when heating temperature increases by 30 °C, phase transition hysteresis decreases by about 3 °C. The cooling temperature decreased by 10 °C, and the phase transition hysteresis increased by 2.69 °C. This paper provides a new idea for optimizing the properties of phase change energy storage materials and provides a possibility for realizing the parametric control of phase change hysteresis factors.

Effect of size and disorder on martensitic phase transition and thermal hysteresis in milled Ni-Mn-In-Co microparticles

Microparticles of Ni45.7Mn36.6In13.5Co4.2 have been prepared by means of different grinding methods (hand-grinding, cryo-milling, planetary ball-milling) followed by annealing treatments in order to recover the original martensitic transition and magnetic properties. A rapid reduction of particle size down to the micrometers has been obtained after few hours of milling, as it results from morphological analyses. Milling temperature, time, and medium strongly impact on the degree of induced stresses and particles aggregation, significantly changing the morphology, crystal structure and magnetic properties. It was found that both magnetic and magneto-structural phase transitions can be recovered by high-temperature annealing treatments (T > 1000 K). Time and temperature of the treatment have been optimized in relation to the disorder introduced by the milling process, which depends on its energy and duration. In general, our results show the strong dependence of the magneto-structural properties of the NiMnInCo compound on microstructural features, atomic order and chemical homogeneity, that imposes a careful selection and improvement of the preparation route.

Hysteresis in the thermally induced phase transition of cellulose ethers.

Functionalized cellulosics have shown promise as naturally derived thermoresponsive gelling agents. However, the dynamics of thermally induced phase transitions of these polymers at the lower critical solution temperature (LCST) are not fully understood. Here, with experiments and theoretical considerations, we address how molecular architecture dictates the mechanisms and dynamics of phase transitions for cellulose ethers. Above the LCST, we show that hydroxypropyl substituents favor the spontaneous formation of liquid droplets, whereas methyl substituents induce fibril formation through diffusive growth. In celluloses which contain both methyl and hydroxypropyl substituents, fibrillation initiates after liquid droplet formation, suppressing the fibril growth to a sub-diffusive rate. Unlike for liquid droplets, the dissolution of fibrils back into the solvated state occurs with significant thermal hysteresis. We tune this hysteresis by altering the content of substituted hydroxypropyl moieties. This work provides a systematic study to decouple competing mechanisms during the phase transition of multi-functionalized macromolecules.