Crystal structure,phase transitions,and thermodynamic properties of magnesium metavanadate(MgV_(2)O_(6))

As a promising anode material for magnesium ion rechargeable batteries,magnesium metavanadate(MgV_(2)O_(6))has attracted considerable research interest in recent years.A MgV_(2)O_(6)sample was synthesized via a facile solid-state reaction by multistep-firing stoichiometric mixtures of MgO and V2O5 powder under an air atmosphere.The solid-state phase transition fromα-MgV_(2)O_(6)toβ-MgV_(2)O_(6)occurred at 841 K and the enthalpy change was 4.37±0.04 kJ/mol.The endothermic effect at 1014 K and the enthalpy change was 26.54±0.26 kJ/mol,which is related to the incongruent melting ofβ-MgV_(2)O_(6).In situ XRD was performed to investigate phase transition of the as-prepared MgV_(2)O_(6)at high temperatures.The cell parameters obtained by Rietveld refinement indicated that it crystallizes in a monoclinic system with the C2/m space group,and the lattice parameters of a=9.280 A°,b=3.501 A°,c=6.731 A°,β=111.76°.The solid-state phase transition fromα-MgV_(2)O_(6)toβ-MgV_(2)O_(6)was further studied by thermal kinetics,indicating that this process is controlled first by a fibril-like mechanism and then by a spherulitic-type mechanism with an increasing heating rate.Additionally,the enthalpy change of MgV_(2)O_(6)at high temperatures was measured utilizing the drop calorimetry,heat capacity was calculated and given as:Cp=208.3+0.03583T-4809000T^(−2)(298-923 K)(J mol^(−1)K^(−1)),the high-temperature heat capacity can be used to calculate Gibbs free energy of MgV_(2)O_(6)at high temperatures.

Metal-to-insulator transitions in 3d-band correlated oxides containing Fe compositions

Metal-to-insulator transitions (MITs),which are achieved in 3d-band correlated transitional metal oxides,trigger abrupt variations in electrical,optical,and/or magnetic properties beyond those of conventional semiconductors.Among such material families,iron(Fe:3d^(6)4s^(2))-containing oxides pique interest owing to their widely tunable MIT properties,which are associated with the various valence states of Fe.Their potential electronic applications also show promise,given the large abundance of Fe on Earth.Representative MIT properties triggered by critical temperature (TMIT) were reported for ReFe_(2)O_(4)(Fe^(2.5+)),ReBaFe_(2)O_(5)(Fe^(2.5+)),Fe_(3)O_(4)(Fe^(2.67+)),Re_(1/3)Sr_(2/3)FeO_(3)(Fe^(3.67+)),Re Cu_(3)Fe_(4)O_(12)(Fe^(3.75+)),and Ca_(1-x)Sr_(x)FeO_(3)(Fe^(4+))(where Re represents rare-earth elements).The common feature of MITs of these Fe-containing oxides is that they are usually accompanied by charge ordering transitions or disproportionation associated with the valence states of Fe.Herein,we review the material family of Fe-containing MIT oxides,their MIT functionalities,and their respective mechanisms.From the perspective of potentially correlated electronic applications,the tunability of the TMITand its resultant resistive change in Fe-containing oxides are summarized and further compared with those of other materials exhibiting MIT functionality.In particular,we highlight the abrupt MIT and wide tunability of TMITof Fe-containing quadruple perovskites,such as Re Cu3Fe4O12.However,their effective material synthesis still needs to be further explored to cater to potential applications.

Complete Universal Scaling in First-Order Phase Transitions

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.

Assessment of challenges and strategies for driving energy transitions in emerging markets:A socio-technological systems perspective

The pursuit of improved quality of life standards has significantly influenced the contemporary mining model in the 21st century.This era is witnessing an unprecedented transformation driven by pressing concerns related to sustainability,climate change,the just energy transition,dynamic operating environments,and complex social challenges.Such transitions present both opportunities and obstacles.The aim of this study is to provide an extensive literature review on energy transition to identify the challenges and strategies associated with navigating transformations in energy systems.Understanding these transformations is particularly critical in the face of the severe consequences of global warming,where an accelerated energy transition is viewed as a universal remedy.Adopting a socio-technological systems perspective,specifically through the application of Actor Network Theory(ANT),this research provides a theoretical foundation while categorising challenges into five distinct domains and outlining strategies across these different dimensions.These insights are specifically tailored for emerging market countries to effectively navigate energy transition while fostering the development of resilient societies.Furthermore,our findings highlight that energy transition encompasses more than a mere technological shift;it entails fundamental changes in various systemic socio-economic imperatives.Through focusing on the role of social structures in transitions,this study makes a significant and innovative contribution to ANT,which has historically been criticised for its limited acknowledgement of social structures.Consequently,we propose an emerging market energy transition framework,which not only addresses technological aspects,but also integrates social considerations.This framework paves the way for future research and exploration of energy transition dynamics.The outcomes of this study offer valuable insights to policymakers,researchers,and practitioners engaged in the mining industry,enabling them to comprehend the multifaceted challenges involved and providing practical strategies for effective resolution.Through incorporating the social dimension into the analysis,we enhance the understanding of the complex nature of energy system transformations,facilitating a more holistic approach towards achieving sustainable and resilient energy transitions in emerging markets and beyond.

Pressure-induced structural,electronic,and superconducting phase transitions in TaSe_(3)

TaSe_(3)has garnered significant research interests due to its unique quasi-one-dimensional crystal structure,which gives rise to distinctive properties.Using crystal structure search and first-principles calculations,we systematically investigated the pressure-induced structural and electronic phase transitions of quasi-one-dimensional TaSe_(3)up to 100 GPa.In addition to the ambient pressure phase(P2_(1)/m-I),we identified three high-pressure phases:P2_(1)/m-II,Pnma,and Pmma.For the P2_(1)/m-I phase,the inclusion of spin-orbit coupling(SOC)results in significant SOC splitting and changes in the band inversion characteristics.Furthermore,band structure calculations for the three high-pressure phases indicate metallic natures,and the electron localization function suggests ionic bonding between Ta and Se atoms.Our electron-phonon coupling calculations reveal a superconducting critical temperature of approximately 6.4 K for the Pmma phase at 100 GPa.This study provides valuable insights into the high-pressure electronic behavior of quasi-one-dimensional TaSe_(3).

New approach to measuring topological phase transitions utilizing Floquet technology

The Floquet technique provides a novel anomalous topological phase for non-equilibrium phase transitions.Based on the high symmetry of the quantum anomalous Hall model,the findings suggest a one-to-one correspondence between the average spin texture and the Floquet quasi-energy spectrum.A new approach is proposed to directly measure the quasienergy spectrum,replacing previous measurements of the average spin texture.Finally,we proposed a reliable experimental scheme based on ion trap platforms.This scheme markedly reduces the measurement workload,improves the measurement fidelity,and is applicable to multiple platforms such as cold atoms and nuclear magnetic resonance.

Farm buildings and agri-food transitions in Southern France:Mapping dynamics using a stakeholder-based diagnosis

This study's goal is to present a dynamic portrait of the farm-buildings environment in Occitania,in Southern France,in order to better identify the transitions underway in agri-food chains.To this end,we undertook a ter-ritorial diagnosis based on actor statements,using 28 semi-structured interviews across Occitania.This diagnosis was enriched by graphic modelling,which enabled the spatialization of the dynamics described.We show that the process of standardisation of farm buildings prevails in the majority of the territories studied.This phenomenon has intensified in recent years with the development of vast photovoltaic-roofed sheds,accentuating the farm-land conversion and soil sealing.At the same time,in areas with strong environmental,landscape and heritage contexts,a'new adventure in farm buildings'(2022 survey)is taking shape.It is primarily driven by local short food chains,which rely on self-construction,repurposing and refurbishment,the sharing of tools and equipment,and which favour the use and reuse of local resources.This study shows that farm-buildings dynamics crystallise many challenges confronting the reterritorialisation of agriculture and food production.

Triple points and phase transitions of D-dimensional dyonic Ad S black holes with quasitopological electromagnetism in Einstein–Gauss–Bonnet gravity

By considering the negative cosmological constant Λ as a thermodynamic pressure, we study the thermodynamics and phase transitions of the D-dimensional dyonic Ad S black holes(BHs) with quasitopological electromagnetism in Einstein–Gauss–Bonnet(EGB) gravity. The results indicate that the small/large BH phase transition that is similar to the van der Waals(vdW) liquid/gas phase transition always exists for any spacetime dimensions. Interestingly, we then find that this BH system exhibits a more complex phase structure in 6-dimensional case that is missed in other dimensions.Specifically, it shows for D = 6 that we observed the small/intermediate/large BH phase transitions in a specific parameter region with the triple point naturally appeared. Moreover, when the magnetic charge turned off, we still observed the small/intermediate/large BH phase transitions and triple point only in 6-dimensional spacetime, which is consistent with the previous results. However, for the dyonic Ad S BHs with quasitopological electromagnetism in Einstein–Born–Infeld(EBI) gravity, the novel phase structure composed of two separate coexistence curves observed by Li et al. [Phys. Rev. D105 104048(2022)] disappeared in EGB gravity. This implies that this novel phase structure is closely related to gravity theories, and seems to have nothing to do with the effect of quasitopological electromagnetism. In addition, it is also true that the critical exponents calculated near the critical points possess identical values as mean field theory. Finally, we conclude that these findings shall provide some deep insights into the intriguing thermodynamic properties of the dyonic Ad S BHs with quasitopological electromagnetism in EGB gravity.

Water Photomolecular Evaporation Due to Light-Mediated Ortho-Para Spin Transitions

Recent discoveries have revealed a groundbreaking phenomenon where light alone, without any thermal input, can induce water evaporation, termed the “photomolecular effect”. This study explores a novel hypothesis that this effect can be explained by ortho-para magnetic spin interactions in water molecules within the water-air interface layer. Water molecules, consisting of hydrogen and oxygen, exhibit different nuclear spin states: ortho-(triplet) and para-(singlet). The interaction of polarized light with these spin states may induce transitions between the rotational levels of ortho- and para-forms due to catalysts like triplet oxygen (O2) in its inhomogeneous magnetic field. Resonance pumping at 532 nm (~18,797 cm−1) due to the transition v1-v2-v3 ~ 0-8-2 (~18,796 cm−1) results in an increase in molecular energy sufficient to overcome intermolecular forces at the water surface, thereby causing evaporation. The proposed ortho-para conversion mechanism involves spin-orbit coupling and specific resonance conditions. This theory provides a quantum mechanical perspective on the photomolecular effect, potentially offering insights into natural processes such as cloud formation and climate modeling, as well as practical applications in solar desalination and industrial drying. Further experimental validation is required to confirm the role of spin interactions in light-induced water evaporation.

Influence of Frohlich Interaction on Intersubband Transitions of InGaAs/InAlAs-Based Quantum Cascade Detector Structures Investigated by Infrared Modulated Photoluminescence

We demonstrate the use of an infrared modulated photoluminescence(PL)method based on a step-scan Fourier-transform infrared spectrometer to analyze intersubband transition(ISBT)of InGaAs/InAlAs quantum cascade detector(QCD)structures.By configuring oblique and parallel excitation geometries,high signal-to-noise ratio PL spectra in near-to-far-infrared region are measured.With support from numerical calculations based on the k·p perturbation theory,the spectra is attributed to intraband and interband transitions of InGaAs/InAlAs QCD structures.Temperature evolution results show that the k-dependent transitions caused by longitudinal optical phonon-assisted scattering(Frohlich interaction)plays an important role in the ISBT.These results suggest that this infrared modulated-PL method has great potential in characterizing QCD devices and conducting performance diagnostics.

Percolation transitions in edge-coupled interdependent networks with directed dependency links

We propose a model of edge-coupled interdependent networks with directed dependency links(EINDDLs)and develop the theoretical analysis framework of this model based on the self-consistent probabilities method.The phase transition behaviors and parameter thresholds of this model under random attacks are analyzed theoretically on both random regular(RR)networks and Erd¨os-Renyi(ER)networks,and computer simulations are performed to verify the results.In this EINDDL model,a fractionβof connectivity links within network B depends on network A and a fraction(1-β)of connectivity links within network A depends on network B.It is found that randomly removing a fraction(1-p)of connectivity links in network A at the initial state,network A exhibits different types of phase transitions(first order,second order and hybrid).Network B is rarely affected by cascading failure whenβis small,and network B will gradually converge from the first-order to the second-order phase transition asβincreases.We present the critical values ofβfor the phase change process of networks A and B,and give the critical values of p andβfor network B at the critical point of collapse.Furthermore,a cascading prevention strategy is proposed.The findings are of great significance for understanding the robustness of EINDDLs.

Floquet dynamical quantum phase transitions in transverse XY spin chains under periodic kickings

Floquet dynamical quantum phase transitions(DQPTs),which are nonanalytic phenomena recuring periodically in time-periodic driven quantum many-body systems,have been widely studied in recent years.In this article,the Floquet DQPTs in transverse XY spin chains under the modulation ofδ-function periodic kickings are investigated.We analytically solve the system,and by considering the eigenstate as well as the ground state as the initial state of the Floquet dynamics,we study the corresponding multiple Floquet DQPTs emerged in the micromotion with different kicking moments.The rate function of return amplitude,the Pancharatnam geometric phase and the dynamical topological order parameter are calculated,which consistently verify the emergence of Floquet DQPTs in the system.

Investigation on influence of alloying on phase transitions of duplex stainless steel based on thermochemical calculation

This paper investigated on influence of different alloying elements added into duplex stainless steel (DSS) on phase transitions using thermochemical methods in comparison with experiment.The results showed that the most possible species in the ferrite phase,austenite phase,σphase,Hcp phase,χphase,and carbide were Cr:Va-type,Fe:Va-type,Ni:Cr:Mo-type,Cr_(2)N-type,Fe_(24)Mo_(10)Cr_(24)-type,and Cr:Mo:C-type,respectively.Furthermore,the Ni,N,Cr,and Mo alloying had significant influences on the transition of each DSS phase.The Ni and N additions obviously raised the temperature at ferrite-1/austenite-1 balance while the Cr and Mo decreased the dual-phase balance temperature.In addition,the Ni addition can promote the precipitating ofσphase at relatively high temperature while the precipitating of Hcp phase at relatively low temperature.The Hcp phase andχphase can be obviously increased by the N addition.The introduction of Cr and Mo notably enhances the precipitation ofσphase.However,the promotion ofχphase precipitation is facilitated by the presence of Mo,while the Cr element acts as an inhibitor forχphase precipitation.Furthermore,the ferrite/austenite ratio tested by experiment was higher than that calculated by thermochemical methods,thus pre-designed solution temperature should be lower about 30-100℃than that calculated by thermochemical methods.

Multi-ASV Collision Avoidance for Point-to-Point Transitions Based on Heading-Constrained Control Barrier Functions With Experiment

Dear Editor, Collision avoidance is critical for safe operations of multiple autonomous surface vehicles(ASVs). It is a challenging task to design collision-free control laws to ensure safety, especially in a crowded sea environment. This letter presents a collision-free pointto-point transition strategy for multiple ASVs subject to static obstacles, dynamic obstacles and neighboring ASVs based on control barrier functions(CBFs).

Metal-organic decomposition growth of thin film metastable perovskite nickelates with kinetically improved quantum transitions

The multiple quantum transitions within d-band correlation oxides such as rare-earth nickelates(RENiO_(3))triggered by critical temperatures and/or hydrogenation opened up a new paradigm for correlated electronics applications,e.g.ocean electric field sensor,bio-sensor,and neuron synapse logical devices.Nevertheless,these applications are obstructed by the present ineffectiveness in the thin film growth of the metastable RENiO_(3)with flexibly adjustable rare-earth compositions and electronic structures.Herein,we demonstrate a metal-organic decompositions(MOD)approach that can effectively grow metastable RENiO_(3)covering a large variety of the rare-earth composition without introducing any vacuum process.Unlike the previous chemical growths for RENiO_(3)relying on strict interfacial coherency that limit the film thickness,the MOD growth using reactive isooctanoate percussors is tolerant to lattice defects and therefore achieves comparable film thickness to vacuum depositions.Further indicated by positron annihilation spectroscopy,the RENiO_(3)grown by MOD exhibit large amount of lattice defects that improves their hydrogen incorporation amount and electron transfers,as demonstrated by the resonant nuclear reaction analysis and near edge X-ray absorption fine structure analysis.This effectively enlarges the magnitude in the resistance regulations in particular for RENiO_(3)with lighter RE,shedding a light on the extrinsic regulation of the hydrogen induced quantum transitions for correlated oxides semiconductors kinetically via defect engineering.

Rubidium-induced phase transitions among metallic,band-insulating,Mott-insulating phases in 1T-TaS_(2)

Realizing phase transitions via non-thermal sample manipulations is important not only for applications,but also for uncovering the underlying physics.Here,we report on the discovery of two distinct metal–insulator transitions in 1T-TaS_(2) via angle-resolved photoemission spectroscopy and in-situ rubidium deposition.At 205 K,the rubidium deposition drives a normal metal–insulator transition via filling electrons into the conduction band.While at 225 K,however,the rubidium deposition drives a bandwidth-controlled Mott transition as characterized by a rapid collapsing of Mott gap and a loss of spectral weight of the lower Hubbard band.Our result,from a doping-controlled perspective,succeeds in distinguishing the metallic,band-insulating,and Mott-insulating phases of 1T-TaS_(2),manifesting a delicate balance among the electronitineracy,interlayer-coupling and Coulomb repulsion.We also establish an effective method to tune the balance between these interactions,which is useful in seeking exotic electronic phases and designing functional phase-changing devices.

Multiple Magnetic Phase Transitions and Critical Behavior in Single-Crystal SmMn_(2)Ge_(2)

Magnetic materials with noncollinear spin configurations have engendered significant interest in condensed matter physics due to their intriguing physical properties.We direct our attention towards the magnetic properties and critical behavior of single-crystal SmMn_(2)Ge_(2),an itinerant magnet with numerous temperature-dependent magnetic phase transitions.Notably,SmMn_(2)Ge_(2)displays significant magnetic anisotropy with easy magnetization direction switching from the c axis to the ab plane as temperature decreases.The critical behavior of the ferromagnetic transition occurring above room temperature is thoroughly examined.Reliable and self-consistent critical exponents,includingβ=0.292(2),γ=0.924(8),andδ=4.164(6),along with the Curie temperature T_c=347 K,are extracted through various methods,which provide evidence for the coexistence of multiple magnetic interactions in SmMn_(2)Ge_(2).Further analysis reveals that the magnetic interaction of SmMn_(2)Ge_(2)is a long-range type with the interaction distance decaying as J(r)~r^(-4.35).

Current bifurcation, reversals and multiple mobility transitions of dipole in alternating electric fields

Anomalous transports of dipole in alternating electric fields are investigated by means of numerical calculation of its average angular velocity(or current). Our results show that the alternating electric fields can make the dipole exhibit many interesting transport behaviors. There exist current bifurcation and multiple current reversal phenomena about frequency of the alternating electric fields in the system in the absence of constant bias force, while many platforms appear in the curve of its average angular velocity vs. the force, i.e., multiple mobility transitions phenomenon in the presence of the constant force, dependent on frequencies of the alternating electric fields. Further investigation indicates that the multiple mobility transitions are attributed to the traveling forces on the dipole. Intrinsic physical mechanism and conditions for the characteristic dynamical behaviors to occur are also discussed in detail. These findings will possess crucial significance for optimizing heating control in the alternating electric fields.

Machine learning potential for Ab Initio phase transitions of zirconia

Zirconia has been extensively used in aerospace,military,biomedical and industrial fields due to its unusual combination of high mechanical,electrical and thermal properties.However,the fundamental and critical phase transition process of zirconia has not been well studied because of its difficult first-order phase transition with formidable energy barrier.Here,we generated a machine learning interatomic potential with ab initio accuracy to discover the mechanism behind all kinds of phase transition of zirconia at ambient pressure.The machine learning potential precisely characterized atomic interactions among all zirconia allotropes and liquid zirconia in a wide temperature range.We realized the challenging reversible first-order monoclinic-tetragonal and cubicliquid phase transition processes with enhanced sampling techniques.From the thermodynamic information,we gave a better understanding of the thermal hysteresis phenomenon in martensitic monoclinic-tetragonal transition.The phase diagram of zirconia from our machine learning potential based molecular dynamics simulations corresponded well with experimental results.

Anion type-dependent confinement effect on glass transitions of solutions of LiTFSI and LiFSI

We present findings on the effect of nanometer-sized silica-based pores on the glass transition of aqueous solutions of lithium bis(trifluoromethane)sulfonimide(LiTFSI)and lithium difluorosulfimide(LiFSI),respectively.Our experimental results demonstrate a clear dependence of the confinement effect on the anion type,particularly for water-rich solutions,in which the precipitation of crystalized ice under cooling process induces the formation of freeze-concentrated phase confined between pore wall and core ice.As this liquid layer becomes thinner,the freeze-concentrated phase experiences glass transition at increasingly higher temperatures in solutions of LiTFSI.However,differently,for solutions of LiFSI and LiCl,this secondary confinement has a negligible effect on the glass transition of solutions confined wherein.These different behaviors emphasize the obvious difference in the dynamic properties’response of LiTFSI and LiFSI solutions to spatial confinement and particularly to the presence of the hydrophilic pore wall.