Kinetic tendencies of thermal transformations in nanosized Ni–MoO3 systems

Abstract

The transformations in nanosized Ni–MoO3 systems were studied by optical spectroscopy, microscopy, and gravimetry depending on the thickness of the Ni (d = 1–40 nm) and MoO3 (d = 3–50 nm) films, temperature (473–773 K), and thermal treatment time. The contact potential difference was measured for Ni and MoO3 films; photovoltage, for Ni–MoO3 systems. An energy band diagram of the Ni–MoO3 systems was constructed. A model of the thermal transformation of MoO3 films in Ni–MoO3 systems was suggested, which involves a redistribution of equilibrium charge carriers at the contact, formation of a [(Vа)++е] center during the preparation of the MoO3 film, the transformation of this center into an [е(Vа)++е] center during the formation of Ni–MoO3 systems, and the thermal transition of an electron to the level of the [(Vа)++е] center to form an [е(Vа)++е] center.