Figure 19.

(a) Temperature–composition phase diagram of the MAPb(I_1–xBr_x)₃ system. Symmetry notation: C - cubic, T - tetragonal, O - orthorhombic. Reprinted (adapted) with permission from ref (367). Copyright 2019 The Royal Society of Chemistry. Green square data point taken from refs (363, 368). (b) PXRD patterns of MAPbI₂Br at different temperatures. (c) Temperature dependence of the real part of the dielectric permittivity of the x = 0, 1/3, 2/3, and 1 compounds measured 1 MHz frequency. Reprinted (adapted) with permission from ref (365). Copyright 2022 Wiley-VCH. (d) Transient anisotropy dynamics of MA cations in the x = 0, 0.5, and 1 compounds. Solid curves show the fits using the wobbling-in-a-cone relaxation model (inset). Adapted with permission from ref (369). Copyright 2017 American Chemical Society.