Silicon oxide (a-SiO) is one of the most used silicon-based materials in optoelectronic and microelectronic technology. Previously, we have reported that the a-SiO, (01) in conditions of variable frequency between 10(2) and 10(6) Hz. The variation of the impedance modulus with the frequency shows a capacitive behaviour: in Log vertical bar Z vertical bar=f(Log omega) plots, the slope of the linear variation is around -1. Studying the argument, the same results have been found [arg Z epsilon(-75; -90 degrees)]. The intensive parameters, the dielectric constant and electrical conductivity, have been calculated. The result this study revealed that a-SiO(x) sputtered thin films are characterised by dielectric relaxation and electrical conductivity (with a transport mechanism described by variable range hopping). (C) 2008 Elsevier B.V. All rights reserved.