Polarized charge transfer spectra of Cu2+doped perovskite layers (RNH3)2CdxMn1−xCl4(x = 0−1)

This work investigates the charge transfer spectra of CuCl6 4- complexes formed in the (RNH3)2CdxMn1-xCl4 crystal series. For x = 1, it is demonstrated that Cu complexes display an elongated D4h symmetry, forming an antiferrodistortive type structure which is similar to that found in the pure copper crystals. The presence of Mn induces an important enhancement of the charge transfer bands as well as significant redshifts. The results are interpreted in terms of distortions of the CuCl6 4- geometry which changes from D4h elongated (x = 1) to nearly D4h compressed (x = 0). The transition energy, polarization and assignment of the charge transfer bands are analysed.