高温高压下钠长石的阻抗谱实验研究

Experimental Study on Impedance Spectra of Albite at High Temperatures and High Pressures

在压力为1.0、2.0GPa和温度为673～973K条件下,采用交流阻抗谱法在YJ-3000t紧装式六面顶高压设备上原位测量了钠长石的电导率。实验结果表明:在实验的温度和压力范围内,钠长石的电导率在10-3.0～10-5.5 S/m变化;钠长石复阻抗的模和相角对频率有很强的依赖性;随着温度T升高,钠长石的电阻率迅速减小,电导率σ增大,并且lgσ与T-1之间符合Arrhenius关系;在实验压力范围内,随着压力升高,钠长石的电导率降低。采用离子导电机制,对高温高压下钠长石的导电行为进行了合理解释。

The electrical conductivity of albite was in-situ measured at pressures of 1.0,2.0 GPa and temperatures of 673-973 K using a.c.impedance spectroscopy method in YJ-3000t multi-anvil press.The experimental results indicate that the electrical conductivity（σ） of albite ranges from 10-3.0 to 10-5.5 S/m.The modulus and phase angle of complex impedance strongly depend on frequency.The electrical conductivity of samples rapidly increases with increasing temperature（T）,and the relationship between lg σ and T-1 fits Arrhenius relation.In addition,the electrical conductivity of samples decreases with increasing pressure in the investigated temperature and pressure range.The dominating conduction mechanism for albite is suggested to be the migration of sodium cations within the channels in the aluminosilicate framework.