Electrical conductivity of K-feldspar at high temperature and high pressure |
| |
| Authors: | Haiying Hu Lidong Dai Heping Li Jianjun Jiang Keshi Hui |
| |
| Institution: | 1. Laboratory for High Temperature and High Pressure Study of the Earth’s Interior Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, Guizhou, 550002, China
2. University of Chinese Academy of Sciences, Beijing, 100039, China
|
| |
| Abstract: | Electrical conductivity measurements on dry polycrystalline K-feldspar were performed at 1.0 to 3.0 GPa and 873 to 1,173 K with a multi-anvil high-pressure apparatus and the Solartron-1260 Impedance/Gain Phase Analyzer in the frequency range of 10?1 to 106 Hz. At each temperature the complex impedance displays a perfect semi-circular arc that represents the grain-interior conduction. Under the experimental conditions, electrical conductivity exponentially increases with increasing temperature and slightly decreases with increasing pressure; however, the effect of pressure on the conductivity is less pronounced than that of temperature. The activation enthalpy decreases slightly from 0.99 to 1.02 eV with increasing pressure, and the activation energy and activation volume for K-feldspar are 0.98 eV and 1.46?±?0.17 cm3/mol, respectively. According to these Arrhenius parameters, ionic conduction is proposed to be the dominant conduction mechanism in K-feldspar at high temperatures and pressures, and potassium ions are the charge carriers transporting by an interstitial mechanism. The diffusion coefficient of potassium at high temperatures was calculated from our conductivity data on K-feldspar using Nernst–Einstein equation, and the results were compared with the previous experimental results. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
