title: Thermally Induced Reversible Double Phase Transitions in an Organic-Inorganic Hybrid Iodoplumbate C4H12NPbI3 with Symmetry Breaking.
abstract: 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.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , Singapore 639798, Singapore.
authors.forename: Guangfeng
authors.initials: G
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou, Fujian 350002, China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Bruker Scientific Technology Co. Ltd , Beijing 100081, China.
authors.forename: Zhenyi
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , Singapore 639798, Singapore.
authors.forename: Lei
authors.initials: L
authors.lastname: Chang
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , Singapore 639798, Singapore.
authors.forename: Junling
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
authors.forename: Xutang
authors.initials: X
authors.lastname: Tao
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , Singapore 639798, Singapore.|Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371, Singapore.
authors.forename: Qichun
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D007455:Iodine; D007854:Lead; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D044367:Phase Transition; D013055:Spectrophotometry, Infrared; D013696:Temperature
chemical_list: D002412:Cations; D009942:Organometallic Compounds; D007854:Lead; D007455:Iodine