Electrical conductivity as a defect property of γ-FeOOH
Abstract
The electrical conductivity of γ-FeOOH, pretreated under 10–3 Pa for 14 h at different temperatures (100–140°C), was determined over the temperature range from –170 to 140°C and at various frequencies (d.c., 200 Hz-10 MHz). The electrical conductivity increased remarkably as the pretreatment temperature was raised. The activation energy for conduction decreased with increases in the pretreatment temperature and with increasing frequency. The conductivity was also decreased considerably by exposing crystals to oxygen. The results are discussed in the framework of small polaron theory with respect to the formation of iron(II) caused by dehydration.