H/F Substitution Induced Large Increase of <i>T</i><sub>c</sub> in a 3D Hybrid Rare‐Earth Double Perovskite Multifunctional Compound
Qi Xu, Le Ye, Rong‐Meng Liao, Zhen An, Chang‐Feng Wang, Le‐Ping Miao, Chao Shi, Heng‐Yun Ye, Yi Zhang
Abstract
Abstract Increasing attention has been devoted to studying perovskite‐type multifunctional stimuli‐responsive materials with multiple channel physical characteristics. However, it remains challenging to simultaneously achieve multifunction and regulate structural phase transition temperature in hybrid perovskites. Here, we report two three‐dimensional organic–inorganic hybrid rare‐earth double perovskite compounds, (HQ) 2 RbEu(NO 3 ) 6 ( 1 , HQ=quinuclidium) and (4FHQ) 2 RbEu(NO 3 ) 6 ( 2 , 4FHQ=4‐fluoro‐quinuclidium), which exhibit ferroelasticity, dielectric switch, and excellent photoluminescence response. The phase transition temperature of 2 increases 169 K compared with 1 through H/F substitution. This result is attributed to the H/F substitution inducing the generation of the Rb‐F coordination bond between cations and anions. Meanwhile, the photoluminescence emission intensity of 2 shows no quench with the increase of temperature, in particular, the emission spectrum achieves fine regulation at high temperatures. This work provides a new solution for the realization of multi‐functions and regulations of the properties based on hybrid perovskite materials with high critical temperatures.