Impedance spectra of hot, dry silicate minerals and rock: Qualitative interpretation of spectra
Impedance spectra of hot, dry silicate minerals and rock: Qualitative interpretation of spectra
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DOI：
10.2138/am-1995-1-206
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发表时间：
1995-02
影响因子：
3.1
通讯作者：
J. Huebner;R. G. Dillenburg
中科院分区：
文献类型：
--
作者：
J. Huebner;R. G. Dillenburg
抽象的阻抗光谱有助于区分谷物内部和晶界对硅胶矿物和岩石的电阻，这也可以区分由于仪器电子的存在，从而区分了低频响应。天然和合成的斜盘测量。在300-850°C和10-20 kbar的情况下，有一些测量值当在复杂平面上构造时，内饰显示为半圆形阻抗，而热单晶和热岩石的样品 - 电极响应则以抑郁症的态度暴露测量不包含以1 kHz的源头来识别响应的来源；找到与样品接触良好的电子，并随时间稳定。界面，大概是在1个bar上的单频测量，可能会低估岩石在相似的温度下的电导率，但要在较高的压力上使用。或在干燥的岩石中，矿物质和岩石在潮湿的岩石中占主导地位在样品电极界面上，有证据表明，电子电荷载体存在于表面，大概是在内部的硅酮矿物质和岩石中。
Abstract Impedance spectroscopy helps distinguish the contributions that grain interiors and grain boundaries make to electrical resistance of silicate minerals and rocks. The technique also distinguishes the low-frequency response due to the presence of instrument electrodes. We measured olivine, orthopyroxene, clinopyroxenes, and both natural and synthetic clinopyroxenite. Measurements were made at 1 bar, from 750 to 1150 °C, and over a frequency range from 106 Hz; some measurements were also made at 300-850 °C and 10-20 kbar. The grain-interior response lies at highest frequency, the sample- electrode response at low frequencies, and the grain boundary response at mid-frequencies. Grain interiors show as semicircular impedance arcs when plotted on the complex plane, and sample-electrode responses of hot single crystals and of hot dry rocks are exhibited as depressed arcs. In comparison, monofrequency measurements contain no information to identify the source of the response; at 1 kHz they detect only the resistance sum of grain interiors and grain boundaries and at low frequency (≤ 1 Hz) are likely to sense all three components. The major experimental problem is to find electrodes that make good contact with the sample and that are stable with time. The effect of pressure (10 kbar, 300-800 °C) is to diminish the resistance associated with grain boundaries and the sample-electrode interface, in the laboratory and presumably in nature. Monofrequency measurements at 1 bar may underestimate the conductivity of rocks at similar temperature but higher pressure. A network of electrical elements is presented for use in interpreting impedance spectra and conductive paths in hot or cold, wet or dry, minerals and rocks at any pressure. In dry rocks, a series network path predominates; in wet rocks, aqueous pore fluid and crystals both conduct. Finite resistance across the sample-electrode interface is evidence that electronic charge carriers are present at the surface, and presumably within, the silicate minerals and rocks measured.