Influence of the Annealing Temperature on the Structural and Electrical Properties of SiOx(Si)&FeyOz(Fe) Films

Abstract

Composite films containing Si and Fe inclusions into oxide matrices naturally combine dielectric and magnetic properties and, as a result, have prospects for a variety of applications. It is very important to investigate their structure and electrical properties depending on the deposition technology and following treatments. In this work, the results on structure, content, and electrical conductivity of the nanocomposite SiO_x(Si)&Fe_yO_z(Fe) films in dependence on the annealing temperature are presented. The films were deposited by an ion-plasma sputtering technique. After that, they were annealed in the temperature range of 400–1000 °C in an Ar atmosphere. The structure and content of the films were investigated by a variety of methods. The existence of Fe nanoinclusions into the oxide matrix of initial and annealed films was observed by the X-ray diffraction method. Based on the obtained results, the existence of the core (Fe)─shell (Fe_yO_z) structure embedded into the oxide SiO_x matrix was concluded. The dielectric–metal transition was revealed during the measurement of current–voltage characteristics. The transition voltage is dependent on the annealing temperature. The qualitative model for the explanation of obtained results has been proposed. It is based on the creation by Fe atoms of additional shallow donor states in the bandgap of the SiO_x matrix.