Technical note dependence of the charge transfer spectra of (C_2H_5NH_3)_2CdCl_4:Cu~2+ with hydrostatic pressure: structural changes around Cu~2+

摘要

This paper investigates the variation of the charge transfer (CT) spectra of the Cu~2+ doped (EtNH_3)_2CdCl_4 (Et=C_2H5) layer perovskite under hydrostatic pressure. The aim is to explain the strong redshift (-4000 cm~1) undergone by the first CT band of the formed CuCl~4_6 complex on passing from (EtNH_3)_2CdCl_4: Cu~2+ to the isomorphous (EtNH_3)_2MnCl_4: Cu~2+ crystal, which is accompanied by a change of color from light Yellow to deep red.