中国科学院地球化学研究所机构知识库

The electrical conductivity of gabbro was investigated at 623-1173 K, 0.5-2.0 GPa and oxygen fugacities controlled by three solid buffers (Cu + CuO, Ni + NiO and Mo + MoO2) using a YJ-3000t multianvil press and Solartron-1260 impedance spectroscopy analyzer within the frequency range 10(-1)-10(6) Hz. The measured electrical conductivity shows an Arrhenius increase with temperature and increases with increasing pressure. The activation energy and activation volume of charge carriers have been determined as 0.72 +/- 0.01 eV and -6.8 +/- 0.69 cm(3)/mol, respectively. The hydrogen-assisted electrical conductivity in gabbro decreases with increasing oxygen fugacity. Furthermore, it is inferred that some hydrogen-related defects with minor concentration (e.g., H'(M) or H-center dot) are the main charge carriers in the sample and provide reasonable explanations for the behavior of electrical conductivity of gabbro at high pressure.