Thermally Induced Reversible Double Phase Transitions in an Organic–Inorganic Hybrid Iodoplumbate C4H12NPbI3 with Symmetry Breaking

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• 作者：Guangfeng Liu ; Jie Liu ; Zhihua Sun ; Zhenyi Zhang ; Lei Chang ; Junling Wang ; Xutang Tao ; Qichun Zhang
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：August 15, 2016
• 年：2016
• 卷：55
• 期：16
• 页码：8025-8030
• 全文大小：376K
• 年卷期：0
• ISSN：1520-510X

文摘

A one-dimensional (1D) organic–inorganic hybrid iodoplumbate crystal (1, C₄H₁₂NPbI₃, TMAPbI₃) can undergo two reversible phase transitions as the temperature decreases. Its dynamic phase-transition behaviors were carefully studied by dielectric measurements, thermal analysis, and variable-temperature crystallographic studies. These results indicate that the phase transitions possess a disorder–order feature with a noncentrosymmetrical intermediate phase structure. Due to the existence of the ordered motion and reorientation of the C₄H₁₂N⁺ cation, 1 undergoes two phase transitions: the first one from space group P6₃/m at room temperature to Pm at 163 K with symmetry breaking, and the second one from space group Pm at 163 K to P6₁ at 142 K with partial symmetry restoration. Our results indicate that there is an existence of a transitional structure with a low symmetry space group during the disorder–order-type phase transitions, which can provide us valuable information to deeply understand the disorder–order phase transition in organic–inorganic hybrids.