Doping effects on growth and properties of oxygen deficient Ga oxide films

• Sn or In doped oxygen deficient Ga oxide films have been grown
• Nanocomposite films are formed via a phase separation
• Metallic clusters are embedded in a stoichiometric matrix
• Superconducting transitions in the Ga and In clusters are observed

The effects of Sn or In doping on the growth of oxygen deficient Ga oxide have been studied. Like in the case of pure oxygen deficient Ga oxide, nanocomposite films are formed with metallic (Ga and Sn or Ga and In) clusters embedded in a stoichiometric oxide matrix. The synthesis of such clusters is related to the difference in the free energy of formation of the various oxides which leads to the phase separation with formation of metallic clusters. The superconducting transition in the Ga and In clusters was observed as well as their melting and freezing transitions during thermal cycling. This chemically driven phase separation appears as a possible approach for the formation of nanocomposite films with particular transport properties (conductivity).