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We investigate the cooling–heating phase transition of the Euler–Heisenberg-AdS black hole. First, the black hole thermodynamic quantities and the state equation are reviewed. Then, we research cooling–heating phase transition and further plot the inversion and isenthalpic curves in the T–P plane. Meanwhile, we find that the inversion temperature gradually decreases with the increase of Euler–Heisenberg parameter a for the inversion curves, while this parameter has no effect in the cooling region, and the isenthalpic curves gradually move to the positive direction of X-axis with the increase of Euler–Heisenberg parameter a in the heating region. In particular, the inversion temperature and pressure of this black hole are negative, we deem that this case is caused by the vacuum polarization and the quantum electrodynamics corrections, which makes the electromagnetic energy (repulsion force) produced by the black hole shield the gravity produced by the black hole mass. In addition, this explanation has been mentioned in previous studies [M. Daniela and B. Nora, Phys. Rev. D 102, 084011 (2020); R. Ruffini, Y. B. Wu and S. S. Xue, Phys. Rev. D 88, 085004 (2013)]. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the effect of pressure on the transport and structural properties of GaTe, InTe, and InGaTe2 is reported. All materials were found to exhibit pressure-induced structural transitions. For GaTe, the ambient structure transforms to a mixed state at 8GPa, which transforms at 15GPa to an ordered state. InTe, which crystallizes in a tetragonal structure, shows transformations at 6 and 14GPa. InGaTe2, also initially tetragonal, undergoes two transitions at 9.25GPa and 13GPa. These transitions have shown noticeable effects on the transport properties. In particular, the Seebeck coefficient for the solid solution changes sign at the first phase transition. From these results, the thermoelectric figure of merit has been evaluated for each material. For some of these materials (InTe and InGaTe2) this yields a lower efficiency than ambient conditions. However, for GaTe, this has been shown to increase the figure of merit by 14 times to 8GPa. [Copyright &y& Elsevier]

Abstract: Slight deviations from the Kurdjumov–Sachs orientation relationship (KS OR) are often observed in the face-centered-cubic/body-centered-cubic (fcc/bcc) transformation systems, and some can be explained on the premise of the parallelism of either the close-packed planes (CPPs) or the close-packed directions (CPDs), as suggested in many models. This work investigates a new OR which deviates from the KS OR in both the CPPs and the CPDs. This OR is determined by requiring the habit plane to contain a single set of periodic dislocations along the invariant line lying in the CPPs. The angles of the double deviation, as a function of the lattice parameter ratio, are proved to be identical. The calculated results for a stainless steel are in good agreement with the experimental observations. The habit plane for the new OR is associated with slightly lower interfacial energy than those with the ORs of single deviation, which might explain the preference by nature in the present case. [Copyright &y& Elsevier]

Abstract: The effects of uniaxial stress on the pressure-induced transition in pure titanium (Ti) are investigated by means of angle dispersive X-ray diffraction in a diamond-anvil cell. Experiments under four different pressure environments reveal that: (1) the onset of the transition depends on the pressure medium used, going from 4.9GPa (no pressure medium) to 10.5GPa (argon pressure medium); (2) the and phases coexist over a rather large pressure range, which depends on the pressure medium employed; (3) the hysteresis and quenchability of the phase is affected by differences in the sample pressure environment; and (4) a short-term laser heating of Ti lowers the transition pressure. Possible transition mechanisms are discussed in the light of the present results, which clearly demonstrate the influence of uniaxial stress in the transition. [Copyright &y& Elsevier]

The performance of many technologies, such as Li- and Na-ion batteries as well as some two-dimensional (2D) electronics, is dependent upon the reversibility of stacking-sequence-change phase transformations. However, the mechanisms by which such transformations lead to degradation are not well understood. This study explores lattice-invariant shear as a source of irreversibility in stacking-sequence changes, and through an analysis of crystal symmetry shows that common electrode materials (graphitic carbon, layered oxides, and layered sulfides) are generally susceptible to lattice-invariant shear. The resulting irreversible changes to microstructure upon cycling ("electrochemical creep") could contribute to the degradation of the electrode and capacity fade. [ABSTRACT FROM AUTHOR]

Using a laser-heated diamond anvil cell, a powdered sample of gallium phosphide was compressed to 17.5 GPa and heated up to 1400 K. The material obtained was characterized at room temperature using synchrotron x-ray diffraction. Experimental results were compared with first-principles calculations. The polymorph observed assumes the simple cubic structure (sc16) initially reported for GaAs at high pressures. Microdiffraction mapping showed variable grain sizes of the synthesized phase, with the largest grains located in the middle of the heated spot. Structural refinements were performed on selected grains. The structure predicted based on first-principles calculations is in close agreement with the experiments. The two Ga–P bonds show similar lengths in sc16-GaP; however, the bond angles differ, resulting in a distorted tetrahedral coordination geometry. [ABSTRACT FROM AUTHOR]

Structural and ion‐ordering phase transitions limit the viability of sodium‐ion intercalation materials in grid scale battery storage by reducing their lifetime. However, the combination of phenomena in nanoparticulate electrodes creates complex behavior that is difficult to investigate, especially on the single‐nanoparticle scale under operating conditions. In this work, operando single‐particle X‐ray diffraction (oSP‐XRD) is used to observe single‐particle rotation, interlayer spacing, and layer misorientation in a functional sodium‐ion battery. oSP‐XRD is applied to Na2/3[Ni1/3Mn2/3]O2, an archetypal P2‐type sodium‐ion‐positive electrode material with the notorious P2‐O2 phase transition induced by sodium (de)intercalation. It is found that during sodium extraction, the misorientation of crystalline layers inside individual particles increases before the layers suddenly align just prior to the P2‐O2 transition. The increase in the long‐range order coincides with an additional voltage plateau signifying a phase transition prior to the P2‐O2 transition. To explain the layer alignment, a model for the phase evolution is proposed that includes a transition from localized to correlated Jahn–Teller distortions. The model is anticipated to guide further characterization and engineering of sodium‐ion intercalation materials with P2‐O2 type transitions. oSP‐XRD, therefore, opens a powerful avenue for revealing complex phase behavior in heterogeneous nanoparticulate systems. [ABSTRACT FROM AUTHOR]

This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02- 06CH11357. Disorder Dynamics in Battery Nanoparticles During Phase Transitions Revealed by Operando Single-Particle Diffraction The authors from Cornell would like to acknowledge the support from National Science Foundation under award number CAREER DMR-1944907. [Extracted from the article]

X-ray microscopy is powerful in that it can probe large volumes of material at high spatial resolution with exquisite chemical, electronic and bond orientation contrast. The development of diffraction-based methods such as ptychography has, in principle, removed the resolution limit imposed by the characteristics of the X-ray optics. Here, using soft X-ray ptychography, we demonstrate the highest-resolution X-ray microscopy ever achieved by imaging 5 nm structures. We quantify the performance of our microscope and apply the method to the study of delithiation in a nanoplate of LiFePO4, a material of broad interest in electrochemical energy storage. We calculate chemical component distributions using the full complex refractive index and demonstrate enhanced contrast, which elucidates a strong correlation between structural defects and chemical phase propagation. The ability to visualize the coupling of the kinetics of a phase transformation with the mechanical consequences is critical to designing materials with ultimate durability. [ABSTRACT FROM AUTHOR]

Batteries, diffraction, operando, single-particles, sodium-ions Disorder Dynamics in Battery Nanoparticles During Phase Transitions Revealed by Operando Single-Particle Diffraction (Adv. Keywords: batteries; diffraction; operando; single-particles; sodium-ions EN batteries diffraction operando single-particles sodium-ions 1 1 1 03/28/22 20220324 NES 220324 B Sodium-Ion Batteries b In article number 2103521, Jason J. Huang and co-workers use operando single particle X-ray diffraction to probe disorder dynamics in individual cathode particles of Nax[Ni SB 1/3 sb Mn SB 2/3 sb ]O SB 2 sb , an archetypal cathode material for sodium-ion batteries. [Extracted from the article]

We have studied BaW04 under compression at room temperature by means of x-ray diffraction and Raman spectroscopy. When compressed with neon as a pressure-transmitting medium (quasihydrostatic conditions), we found that BaW04 transforms from its low-pressure tetragonal structure into a much denser monoclinic structure. This result confirms our previous theoretical prediction based on ab initio calculations that the scheelite to BaW04-II transition occurs at room temperature if kinetic barriers are suppressed by pressure. However, our experiment without any pressure-transmitting medium has resulted in a phase transition to a completely different structure, suggesting nonhydrostaticity may be responsible for previously reported rich polymorphism in BaW04. The crystal structure of the low- and high-pressure phases from the quasihydrostatic experiments has been Rietveld refined. Additionally, for the tetragonal phase the effects of pressure on the unit-cell volume and lattice parameters are discussed. Finally, the pressure evolution of the Raman modes of different phases is reported and compared with previous studies. [ABSTRACT FROM AUTHOR]

AgClO4 has been studied under compression by x-ray diffraction and density functional theory calculations. Experimental evidence of a structural phase transition from the tetragonal structure of AgClO4 to an orthorhombic barite-type structure has been found at 5.1 GPa. The transition is supported by total-energy calculations. In addition, a second transition to a monoclinic structure is theoretically proposed to take place beyond 17 GPa. The equation of state of the different phases is reported as well as the calculated Raman-active phonons and their pressure evolution. Finally, we provide a description of all the structures of AgClO4 and discuss their relationships. The structures are also compared with those of AgCl in order to explain the structural sequence determined for AgClO4. [ABSTRACT FROM AUTHOR]

In Ge2Sb2Te5 (GST), the prototype phase-change alloy for data storage, in situ x-ray diffraction experiments reveal a pressure-induced crystalline-amorphous-crystalline transition sequence, all at the same fixed composition and in one experimental cycle. A body-centered-cubic polymorph is discovered at high pressures; the formation of this phase is attributable to its high packing density rendered possible by the switch from covalent to metallic bonding as predicted by ab initio calculations. [ABSTRACT FROM AUTHOR]