Measurement of electrical conductivity of magnesium oxide single crystal at high temperature using a solar furnace

Abstract

Several workers[1–6] have reported measurements of the electrical conductivity of magnesium oxide crystals at temperatures up to 1700°C. The results obtained are divergent, and the conclusions in some cases contradictory. The authors have attempted to measure this parameter in the temperature range 1300 to 2200°C. To this end we have used two types of furnaces—a solar furnace and a graphite resistance furnace. This paper reports mainly on the techniques developed and the results obtained using the Solar Furnace. The plot of the logarithm of conductivity vs reciprocal of absolute temperature shows a significant change in slope near temperatures of 1800°C, and a further change near temperatures of 2100°C.