The supramolecular lead iodide perovskite crystals, {[NH(18-crown-6)]PbI} (1), (18-crown-6 = 1,4,7,10,13,16-hexaoxacyclooctadecane), was successfully achieved by a facile solvent evaporation strategy using a DMF solution containing equal molar quantities of PbI, NHI and 18-crown-6. The supramolecular perovskite was characterized by microanalysis for C, H and N elements, thermogravimetric (TG) analysis, differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and single crystal X-ray diffraction techniques. DSC measurements demonstrated that 1 experiences a two-step thermotropic phase transition around 333 K and 383 K, respectively. The phase transition is relevant to the disorder-order transformation of the 18-crown-6 molecule at ∼333 K, while both breaking-symmetry and ordered-disordered transformation of the 18-crown-6 molecule occurred at ∼383 K. In addition, the sharp change of the PbI coordination octahedron distortion degree plays a synergistic role in the two-step phase transition. The dielectric relaxation occurs above 243 K in 1 and is mainly attributed to the displacement of the NH ions relative to the ring of the 18-crown-6 molecule and {PbI} chain induced by an AC electrical field.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/d2dt02621j | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Transition from the topological to the chaotic in the nonlinear Su-Schrieffer-Heeger model.
Nat Commun
January 2025
Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Recent studies on topological materials are expanding into the nonlinear regime, while the central principle, namely the bulk-edge correspondence, is yet to be elucidated in the strongly nonlinear regime. Here, we reveal that nonlinear topological edge modes can exhibit the transition to spatial chaos by increasing nonlinearity, which can be a universal mechanism of the breakdown of the bulk-edge correspondence. Specifically, we unveil the underlying dynamical system describing the spatial distribution of zero modes and show the emergence of chaos.
View Article and Find Full Text PDFCoalescence of multiple topological orders in quasi-one-dimensional bismuth halide chains.
Nat Commun
January 2025
School of Physics, Beihang University, Haidian District, Beijing, China.
Topology is being widely adopted to understand and to categorize quantum matter in modern physics. The nexus of topology orders, which engenders distinct quantum phases with benefits to both fundamental research and practical applications for future quantum devices, can be driven by topological phase transition through modulating intrinsic or extrinsic ordering parameters. The conjoined topology, however, is still elusive in experiments due to the lack of suitable material platforms.
View Article and Find Full Text PDFEnhanced energy storage in antiferroelectrics via antipolar frustration.
Nature
January 2025
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
Dielectric-based energy storage capacitors characterized with fast charging and discharging speed and reliability play a vital role in cutting-edge electrical and electronic equipment. In pursuit of capacitor miniaturization and integration, dielectrics must offer high energy density and efficiency. Antiferroelectrics with antiparallel dipole configurations have been of significant interest for high-performance energy storage due to their negligible remanent polarization and high maximum polarization in the field-induced ferroelectric state.
View Article and Find Full Text PDFSignatures of longitudinal spin pumping in a magnetic phase transition.
Nature
January 2025
Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea.
A particle current generated by pumping in the absence of gradients in potential energy, density or temperature is associated with non-trivial dynamics. A representative example is charge pumping that is associated with the quantum Hall effect and the quantum anomalous Hall effect. Spin pumping, the spin equivalent of charge pumping, refers to the emission of a spin current by magnetization dynamics.
View Article and Find Full Text PDFMental Well-being in Menopause.
Obstet Gynecol Clin North Am
March 2025
Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA. Electronic address:
The hormonal changes that accompany the transition to menopause are disruptive to most women, and for some, mental health maybe adversely affected. Depressive symptoms and major depression are the best-studied conditions in association with menopause, but anxiety, executive function, and comorbid pre-existing psychiatric conditions all influence the symptomatology that women will experience during this phase of their lives. The epidemiology, diagnosis, and evidence-based treatment guidelines for perimenopausal patients are discussed.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!