Predicting and Screening Dielectric Transitions in a Series of Hybrid Organic-Inorganic Double Perovskites via an Extended Tolerance Factor Approach

Extended Goldschmidt tolerance factor t is applied to the hybrid double perovskites (MA)(2)[BB(CN)(6)] (MA=methylammonium cation) to predict and screen dielectric transitions in 121 compounds through the correlations among t, the radius of the B component r(B) and the transition temperature T-c, based on experimental results from model compounds. For (MA)(2)[BCo(CN)(6)], it is concluded that: i)when t>0.873, the cubic phase would be stable below 298K; ii)when 0.873>t>0.805, the cubic phase would be stable between 298 and 523K; iii)the larger the r(B), the higher the T-c of the perovskite (T(c)(1/2)r(B)); and iv)the T-c of the hybrid perovskites can be well tuned by doping the B components.