In recent years,it has been found that the flexibility of structure and diversity of the components endow quite an amount of the organic-inorganic hybrid perovskites with novel properties,i.e.,structural phase transit...In recent years,it has been found that the flexibility of structure and diversity of the components endow quite an amount of the organic-inorganic hybrid perovskites with novel properties,i.e.,structural phase transitions.Considering the natural advantage of the perovskite-type structure in generation of stimuliresponsive or smart materials,we synthesized an organic-inorganic hybrid rare-earth double perovskitetype compound,(DMP)_(2) LaRb(NO_(3))_(6)(DMP=N,N-dimethylpyrrolidinium cation,1).It shows reversible phase transition at 219/209 K(heating/cooling).Variable-temperature single-crystal structure analysis and dielectric constant measurements reveal that the thermal vibrations of the polar cation guests and the distortion of the anionic cage-like framework are the origin of the phase transition.Meanwhile,the movement of polar cation in crystal lattices arouses dielectric transition between the low-and highdielectric states,resulting in a switchable property of dielectric constant.The results reveal that the rare-earth double perovskite provides a promising platform for achieving switchable physical/chemical properties.展开更多
基金Project supported by the National Natural Science Foundation of China(21805119,21875093)Youth Science Foundation of Jiangxi Provincial Office of Science and Technology(20192ACBL21010)Natural Science Foundation of Jiangxi Province(20204BCJ22015,20202ACBL203001)。
文摘In recent years,it has been found that the flexibility of structure and diversity of the components endow quite an amount of the organic-inorganic hybrid perovskites with novel properties,i.e.,structural phase transitions.Considering the natural advantage of the perovskite-type structure in generation of stimuliresponsive or smart materials,we synthesized an organic-inorganic hybrid rare-earth double perovskitetype compound,(DMP)_(2) LaRb(NO_(3))_(6)(DMP=N,N-dimethylpyrrolidinium cation,1).It shows reversible phase transition at 219/209 K(heating/cooling).Variable-temperature single-crystal structure analysis and dielectric constant measurements reveal that the thermal vibrations of the polar cation guests and the distortion of the anionic cage-like framework are the origin of the phase transition.Meanwhile,the movement of polar cation in crystal lattices arouses dielectric transition between the low-and highdielectric states,resulting in a switchable property of dielectric constant.The results reveal that the rare-earth double perovskite provides a promising platform for achieving switchable physical/chemical properties.