Electrical conductivity measurements were carried out on synthetic FeTi O3 ilmenite with a KAWAI-type multianvil high-pressure apparatus (USSA-5000). The temperature range was 300-600 K and the pressure range was 8-16 GPa. The activation energy and the activation volume were calculated to be 0.21 eV and -0.22 cm3 mol, respectively. The low value of the activation energy and the small negative activation volume are consistent with conduction by hopping of small polarons, suggested to be an intervalence charge transfer Fe2+ + Ti4+ → Fe3+ + Ti3+. In comparison with the electrical conductivity of (Mg0.93, Fe0.07) Si O3 ilmenite with a larger activation volume of -0.90 cm3 mol, we suggest that Fe2+ → Fe3+ hopping conduction is the dominant conduction mechanism in (Mg,Fe) Si O3 ilmenite and significant lattice disorder was involved at high temperature.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2006 Apr 12|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics