Mixed and carbon filled oxide materials as gamma radiation sensors

Throughout this work radiation-induced changes in the optical, electrical and structural properties of mixed and carbon filled metal oxides were studied. Oxides such as NiO, CeO2, TeO2, In2O3, SiO and MnO in the form of thin and thick films were used. The properties of the materials undergo changes by the influence of gamma-rays. The degree of these radiation-induced changes serves as a measure of received radiation dose. Deep understanding of physical properties of the materials under the influence of radiation is vital for the effective design of dosimeters. In this work all films were exposed to a disk-type Cs-137 source with an activity of 370kBq. Carbon filling and mixing oxides in various proportions was found to control the properties of semiconductor films in terms of their susceptibility to radiation exposure. For example, planar NiO thick film structures with Ag interdigitated electrodes showed an increase in the values of current with the increase in radiation dose up to 171 mu Sv. Doping of NiO thick films with 0.1 wt.% of carbon resulted in larger increments in the values of current and the increasing the working range to 2720 mu Sv. The possibility to fabricate a device that would satisfy the requirement of particular application, in this case the sensitivity to gamma-radiation exposure and working dose region, was experimentally demonstrated. (c) 2004 Elsevier B.V. All rights reserved.