In this Letter, we discuss the dramatically enhanced electrostriction and dielectric constant in an all-organic composite consisting of polyvinylidene fluoride trifluoroethylene [P(VDF-TrFE)] copolymer matrix and copper-phthalocyanine (CuPc) particles, which could not be explained by traditional composite theory. Using a Landau-type potential energy combined with energy minimization, we demonstrate that the dramatic property enhancement is due to the exchange coupling between the dielectrically hard P(VDF-TrFE) and dielectrically soft CuPc, which becomes dominant when the heterogeneity size of the composite is comparable to the exchange length. The exchange coupling is a very effective mechanism for the enhancement of functional properties in ferroelectric and dielectric systems, and its variation with various material parameters is demonstrated and discussed.
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http://dx.doi.org/10.1103/PhysRevLett.90.217601 | DOI Listing |
Dalton Trans
January 2025
Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 30, 48149 Münster, Germany.
The cadmium-rich intermetallic compounds RhCd ( = Ca, Sr, Y, La-Nd, Sm-Lu) were synthesized from the elements in sealed tantalum tubes. The elements were reacted in an induction furnace and the samples were post-annealed to increase phase purity and crystallinity. The RhCd phases crystallize with the cubic CeCrAl type structure, space group 3̄.
View Article and Find Full Text PDFNPJ Comput Mater
January 2025
Computational Atomic-scale Materials Design (CAMD), Department of Physics, Technical University of Denmark, Kgs. Lyngby, Denmark.
We conduct a systematic investigation of the role of Hubbard U corrections in electronic structure calculations of two-dimensional (2D) materials containing 3 transition metals. Specifically, we use density functional theory (DFT) with the PBE and PBE+U approximations to calculate the crystal structure, band gaps, and magnetic parameters of 638 monolayers. Based on a comprehensive comparison to experiments we first establish that the inclusion of the U correction worsens the accuracy for the lattice constants.
View Article and Find Full Text PDFBiomacromolecules
January 2025
Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 15 Kent Ridge Crescent, Singapore 119276, Singapore.
Amphiphilic polymers with distinct polarity differences, known as sharp polarity contrast polymers (SPCPs), have gained much attention for their ability to form micelles with low critical micelle concentrations (CMCs) and potential in anticancer drug delivery. This study addresses the limited research on structure-property relationships of SPCPs by developing various SPCPs and exploring their physicochemical properties and biological applications. Specifically, the superhydrophobic aliphatic palmitoyl (Pal) was coupled to the superhydrophilic zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) (pMPC) to form Pal-pMPC diblock copolymers.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia.
This study investigates the motion of an electron in a Coulomb potential driven by an intense linearly polarized XUV laser pulse analyzed using Gordon-Volkov wave functions. The wave function is decomposed into spherical partial waves to model the scattered electron wave packet after the recollision with a proton. This interaction triggers high harmonic generation, producing coherent X-ray pulses with frequencies that are integer multiples of the XUV field.
View Article and Find Full Text PDFDalton Trans
January 2025
School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, Jiangsu, China.
Five alkali metal manganese(III) fluorophosphates, KMn(POF)F (I), RbMn(POF)F (II), RbMn(POF)(PO)F (III), RbMn(POF)(PO)F (IV), and CsMn(POF)F (V), were successfully synthesized using a hydrothermal method. The monofluorophosphate anion (POF) groups work as "chemical scissors" to promote low-dimensional spin structures with the aid of alkali metal cations. I and II had an = 2 uniform chain structure formed by corner-sharing -MnOF octahedra.
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