Abstract
Since humanity has existed, natural materials have been used in our daily lives; they have been utilized as raw materials in manufacturing from the pin to the jet. Natural calcite and quartz are used as raw materials in various applications, including agriculture, cement, chemical and pharmaceutical, glass, ceramics, and optical fiber; however, the studies on the high-temperature dependence of their electrical and dielectric properties are still scarce and limited. Herein, the electrical and dielectric properties of the natural calcite and quartz have been investigated in the temperature range of 300-1000 K at different frequencies. The electrical conductivity results revealed that natural calcite and quartz appeared to be insulators with stable behavior up to 730 and 640 K, respectively; then, they behaved as semiconductors at higher temperatures. The results revealed the conduction mechanism in both samples seems to be by the charge carriers hopping at the lower temperatures then turning into polarons conduction at the higher temperatures. Both dielectric constant and dielectric loss of the natural calcite and quartz showed temperature-dependent behavior up to 700 K at the low frequencies. Then, they showed frequency-dependent behavior at high frequencies. The stable behavior of electrical and dielectric properties of natural calcite and quartz could make them candidate materials to be used as high-voltage power insulators up to a temperature of 700 K.