超高压下氧化物电导率测量及下地幔电导率的讨论

MEASUREMENTS OF ELECTRICAL CONDUCTIVITIES OF SOME OXIDES AT ULTRAHIGH PRESSURE AND THEIR IMPLICATIONS FOR LOWER MANTLE CONDUCTIVITY

在金刚石对顶砧压机上,对一些氧化物进行了0—30 GPa 压力范围下的电导率测量,发现所测氧化物可按其电导性质为两类:过渡族元素氧化物和非过渡族元素氧化物前者平均电导率较高且有正压效应,后者平均电导率较低且压力效应不明显.过渡族元素氧化物的高导性质对讨论下地幔的电导事和化学模式具有重要意义.结合前人的研究成果,半定量地估计了700 km 处下地幔的电导率.

Using DAC we measured the electrical conductivities of some oxides at pressure up to 30 GPa andambient temperature.The oxides can be divided into two kinds according to their electrical conductivitycharacteristics.The first kind,the transition element oxides,has generally high conductivities and positivepressure effects.While the second,nontransition element oxides,has generally low conductivities and weakpressure effects.The high conductivity of transition element oxides are meaningful for explaining the elec-trical conductivity of lower mantle.Combining with previous results,we semiquantitatively discuassed theelectrical conductivity at 700 km deep mantle.