Synthesis of Cu 2Mo 6S 8 powders and thin films from intermediate oxides prepared by polymeric precursor method

Abstract

Powders and thin films of the copper molybdenum sulfide Cu 2Mo 6S 8 were synthesized from intermediate oxides prepared by polymeric precursor method based on Pechini process. In the case of the thin films, deposition was performed onto R-plane sapphire single crystal by spin coating. The influence of temperature and duration of the 3 step heat treatment cycle (calcination, sulfurization and reduction) were investigated to optimize the synthesis conditions. The first step of calcination under air atmosphere performed for 3 h at 450 °C and 400 °C is suitable to obtain the intermediate oxides powders and thin films, respectively. The sulfurization treatment at 600 °C for 2 h under H 2S/H 2 gas flow followed by reduction at 650 °C for 4 h under H 2 gas flow allowed to obtain Cu 2Mo 6S 8 in powder or thin film form. In the last case, a multilayer process led to dense and homogeneous films. Moreover, the insertion and superconducting behaviour of the final powders allowed to validate the Cu 2Mo 6S 8 synthesis by this moderate temperature process. © 2012 Elsevier Masson SAS. All rights reserved.