Fe_3O_4的高压电学性质

Electrical Property of Fe_3O_4 at a High Pressure

基于金刚石对顶砧(DAC)上的原位电阻率测量技术,测量Fe3O4粉末在高压下的电阻率及磁阻率,得到了样品电阻率随压力的变化关系.当压力大于或小于6GPa时,电阻率随压力的增加均呈下降趋势,但减小的速率不同;当压力小于6GPa时,样品呈正的磁阻效应;当压力大于6GPa时,样品呈负的磁阻效应.结果表明Fe3O4的微观结构在6GPa发生变化.

The resistivity and magnetoresistance of FeaO4 were investigated at a high pressure by means of irvsitu electrical resistivity measurement with diamond anvil cell. We obtained the relation- ship of resistivity as a function of pressure. When p〉6 GPa or p〈6 GPa, the resistivity of Fe304 decreases with increasing pressure. Its dropdown speed at pressure p〈6 GPa is faster than that at pressure higher than 6 GPa. When p〈6 GPa, the sample shows a normal magnetic resistance effect. When p〉6 GPa, the sample shows a negative magnetic resistance effect. This phenomenon indicates that an electronic phase related to electron spin happens at 6 GPa.