Phase Transition, Dielectric Properties, and Ionic Transport in the [(CH3)2NH2]PbI3 Organic–Inorganic Hybrid with 2H-Hexagonal Perovskite Structure
| Autor: | María Antonia Señarís-Rodríguez, Juan Manuel Bermúdez-García, Ramón Artiaga, Wei Ren, Jorge López-Beceiro, Socorro Castro-García, Antonio L. Llamas-Saiz, Alessandro Stroppa, Manuel Sánchez-Andújar, Alberto García-Fernández, Shunbo Hu |
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| Rok vydání: | 2017 |
| Předmět: |
Phase transition
Chemistry Band gap Ionic bonding 02 engineering and technology Dielectric Conductivity 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Dielectric spectroscopy Inorganic Chemistry Crystallography Phase (matter) Mechanosynthesis Physical and Theoretical Chemistry 0210 nano-technology |
| Zdroj: | Inorganic Chemistry. 56:4918-4927 |
| ISSN: | 1520-510X 0020-1669 |
| Popis: | In this work, we focus on [(CH3)2NH2]PbI3, a member of the [AmineH]PbI3 series of hybrid organic–inorganic compounds, reporting a very easy mechanosynthesis route for its preparation at room temperature. We report that this [(CH3)2NH2]PbI3 compound with 2H-perovskite structure experiences a first-order transition at ≈250 K from hexagonal symmetry P63/mmc (HT phase) to monoclinic symmetry P21/c (LT phase), which involves two cooperative processes: an off-center shift of the Pb2+ cations and an order–disorder process of the N atoms of the DMA cations. Very interestingly, this compound shows a dielectric anomaly associated with the structural phase transition. Additionally, this compound displays very large values of the dielectric constant at room temperature because of the appearance of a certain conductivity and the activation of extrinsic contributions, as demonstrated by impedance spectroscopy. The large optical band gap displayed by this material (Eg = 2.59 eV) rules out the possibility that the observ... |
| Databáze: | OpenAIRE |
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