Thermal, ferroelastic, and structural properties near phase transitions of organic–inorganic perovskite type [NH(3)(CH(2))(3)NH(3)]CdBr(4) crystals

Hybrid perovskites have potential applications in several electrochemical devices such as supercapacitors, batteries, and fuel cells. Therefore, we studied the thermal behavior and structural dynamics of organic–inorganic hybrid perovskite [(NH(3))(CH(2))(3)(NH(3))]CdBr(4) crystals near phase transition temperatures, T(C2) (=328 K) and T(C1) (=363 K), which are correlated to the structural dynamics of cations and anions. The structural geometry and molecular dynamics with emphasis on the role of the [(NH(3))(CH(2))(3)(NH(3))] cation and CdBr(6) anion were discussed in terms of MAS (1)H NMR, MAS (13)C NMR, (14)N NMR, and (113)Cd NMR as a function of the temperature. The environments surrounding (1)H, (13)C, (14)N, and (113)Cd are investigated near T(C1) and T(C2) using these results. Spin–lattice relaxation times T(1ρ) were discussed in terms of the change in temperature. The discontinuous changes of (1)H T(1ρ) and (13)C T(1ρ) near T(C1) are consistent with the change of the lattice constant. Shorter T(1ρ) values at high temperature indicate that (1)H and (13)C in the organic chains are more flexible at these temperatures. Based on these results, the physicochemical properties of the cation and anion during the III–II–I phase transitions were discussed. This study was conducted to improve the relatively weak thermal stability compared to the high efficiency for a variety of applications.