Structural phase transition and dielectric switching in an organic-inorganic hybrid rare-earth double perovskite-type compound: (DMP)2LaRb(NO3)6 (DMP = N,N-dimethylpyrrolidinium cation)

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 stimuli-responsive or smart materials, we synthesized an organic-inorganic hybrid rare-earth double perovskite-type compound, (DMP)(2)LaRb(NO3)(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 high-dielectric 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. (c) 2021 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.

Automated summary

The synthesized organic-inorganic hybrid rare-earth double perovskite-type compound shows reversible phase transition and switchable dielectric constant properties, with the origin of phase transition attributed to the thermal vibrations of the polar cation guests and the distortion of the anionic cage-like framework. The rare-earth double perovskite provides a promising platform for achieving switchable physical/chemical properties.