Reflectivity and Electronic Structures of Layered Ionic Crystals (C_<i>n</i>H_2<i>n</i>+1NH₃)₂CuCl₄:<i>n</i>=1, 2, 3

Abstract

The reflection spectra of (C n H 2 n +1 NH 3 ) 2 CuCl 4 ( n =1, 2, 3) were measured in the photon energy region of 2.6–25 eV at room temperature (RT) and liquid nitrogen temperature (LNT) by means of synchrotron radiation. The absorption peak at around 3.3 eV (LNT) has a doublet structure and the splitting energy is 0.08 eV, which is the same magnitude as the spin-orbit splitting of a chlorine atom. The band is assigned as an electronic transition from the chlorine 3 p valence band to the copper 4 s lowest conduction band.