Short-range polar order in the relaxor ferroelectric material (PMN-28PT) have been studied using neutron diffuse scattering. An external electric field along the direction can affect the diffuse scattering in the low temperature rhombohedral/monoclinic phase. Diffuse scattering intensities associated with short-range polarizations are partially suppressed, while those arising from polarizations are enhanced. On the other hand, short-range polar order along other equivalent directions, i.e., , , [011], and directions, are virtually unaffected by the field. Our results, combined with previous work, strongly suggest that most parts of short-range polar order in PMN-PT relaxor systems are robust in the low temperature phase, where they couple strongly to ferroelectric polarizations of the surrounding ferroelectric domains, and would only respond to an external field indirectly through ferroelectric domain rotation.
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http://dx.doi.org/10.1103/physrevb.100.024113 | DOI Listing |
J Phys Chem Lett
January 2025
Kenneth S. Pitzer Theory Center and Department of Chemistry, University of California, Berkeley, California 94720, United States.
This work constructs an advanced force field, the Completely Multipolar Model (CMM), to quantitatively reproduce each term of an energy decomposition analysis (EDA) for aqueous solvated alkali metal cations and halide anions and their ion pairings. We find that all individual EDA terms remain well-approximated in the CMM for ion-water and ion-ion interactions, except for polarization, which shows errors due to the partial covalency of ion interactions near their equilibrium. We quantify the onset of the dative bonding regime by examining the change in molecular polarizability and Mayer bond indices as a function of distance, showing that partial covalency manifests by breaking the symmetry of atomic polarizabilities while strongly damping them at short-range.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China.
Next-generation advanced high/pulsed power capacitors rely heavily on dielectric ceramics with high energy storage performance. Although high entropy relaxor ferroelectric exhibited enormous potential in functional materials, the chemical short-range order, which is a common phenomenon in high entropy alloys to modulate performances, have been paid less attention here. We design a chemical short-range order strategy to modulate polarization response under external electric field and achieve substantial enhancements of energy storage properties, i.
View Article and Find Full Text PDFPLoS Genet
January 2025
Department of Molecular Biosciences, Program in Molecular, Cellular, and Developmental Biology, KU Center for Genomics, University of Kansas, Lawrence, Kansas, United States of America.
Recent studies in vertebrates and Caenorhabditis elegans have reshaped models of how the axon guidance cue UNC-6/Netrin functions in dorsal-ventral axon guidance, which was traditionally thought to form a ventral-to-dorsal concentration gradient that was actively sensed by growing axons. In the vertebrate spinal cord, floorplate Netrin1 was shown to be largely dispensable for ventral commissural growth. Rather, short range interactions with Netrin1 on the ventricular zone radial glial stem cells was shown to guide ventral commissural axon growth.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Polymer Science and Engineering, Key Laboratory of High-Performance Polymer Materials and Technology of MOE, State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing, China.
Overheating remains a major barrier to chip miniaturization, leading to device malfunction. Addressing the urgent need for thermal management promotes the development of solid-state electrocaloric cooling. However, enhancing passive heat dissipation through two-dimensional materials in electrocaloric polymers typically compromises the electrocaloric effect.
View Article and Find Full Text PDFChem Sci
December 2024
Department of Chemistry, Biology and Biotechnology, University of Perugia Via Elce di Sotto, 8 06123 Perugia Italy
The majority of enantioselective organocatalytic reactions occur in apolar or weakly polar organic solvents. Nevertheless, the influence of solute-solvent van der Waals forces on the relative kinetics of competitive pathways remains poorly understood. In this study, we provide a first insight into the nature and strength of these interactions at the transition state level using advanced computational tools, shedding light into their influence on the selectivity.
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