A High-Temperature Electrical Conduction Mechanism in the Lower Mantle Phase (Mg,Fe)1-xO |
| |
| Authors: | DP Dobson NC Richmond JP Brodholt |
| |
| Institution: | Department of Geological Sciences, University College London, London WC1E 6BT, UK. |
| |
| Abstract: | Measurements of electrical conductivity at high pressure and temperature were taken on the lower mantle phase magnesiowustite with varying Fe3+ content. Although previous measurements at atmospheric pressure suggest Fe2+-Fe3+ hopping (small polaron) as the dominant conductivity mechanism, the present experiments show a change in charge transport mechanism with temperature. The lower temperature measurements are consistent with small polaron conduction, but at higher temperatures, which are more applicable to the lower mantle, a large polaron mechanism is suggested. Because these mechanisms have different temperature and compositional dependencies, this transition has important implications for extrapolation to mantle conditions. |
| |
| Keywords: | |
| 本文献已被 PubMed 等数据库收录！ |
|
