Etude par diffraction des rayons x et spectroscopie des photoelectrons de l'environnement et des degres d'oxydation du metal dans les oxydes: Pb 2PtO 4, PbPt 2O 4 ET Bi 1,6Pb 0,4PtO 4.

Abstract

A knowledge of the structure and oxidation state of the metal allows to predict the possible conductivity type of the metal oxides. The compounds Bi 1.6Pb 0.4PtO 4 and PbPt 2O 4 exhibit a semi-conductor and conductor character, respectively, resulting from the existence of the transition metal at different oxidation states within these oxides. The structural determinations show that, in all cases, platinum exists at two oxidation states (+2 in square-planar environment and +4 in octahedral environment) along the metallic chain. Pb 2PtO 4 is an insulator and platinum, in this case, has a unique oxidation state (+4) in an octahedral environment. A photoelectron spectroscopic study supported all the results obtained by X-ray diffraction.