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Two-step thermotropic phase transition and dielectric relaxation in 1D supramolecular lead iodide perovskite [NH4@18-crown ether]PbI3.
- Source :
-
Dalton Transactions: An International Journal of Inorganic Chemistry . 10/21/2022, Vol. 51 Issue 39, p15158-15165. 8p. - Publication Year :
- 2022
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Abstract
- The supramolecular lead iodide perovskite crystals, {[NH4(18-crown-6)]PbI3}∞ (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 PbI2, NH4I 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 PbI6 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 NH4+ ions relative to the ring of the 18-crown-6 molecule and {PbI3}∞ chain induced by an AC electrical field. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14779226
- Volume :
- 51
- Issue :
- 39
- Database :
- Academic Search Index
- Journal :
- Dalton Transactions: An International Journal of Inorganic Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 159604827
- Full Text :
- https://doi.org/10.1039/d2dt02621j