Abstract
Perovskite Layer compounds with the general formula (CnH2n+1NH3)2MX4 (CnMX4 for short) or [NH3-(CH2)n-NH3] MX4 (Short notation 2CnMX4) where M is a divalent metal atom and X an halogen (M = Cu, Mn, Zn, Co, Cd…) (X = Cl, Br…) are lamellar type structures and typical “Sandwich” system because of the regular alternation of inorganic and hydrocarbon regions that consist of long chain alkylammonium groups ionically bonded to an inorganic support. Perovskite Layer compounds are Phase Change Material which have solid-solid transitions and thermal properties good for Thermal Energy Storage. UV-Visible absorption measurements was taken for six samples synthesized in our lab, from the spectrums we defined a charge transfer transitions and try to find the influence of the organic chain and the nature of metal on these transitions. Intra-atomic d-d transition was expected for cupric compounds.