Magnetic Susceptibility of Mercuric Oxide at Various Temperatures

Abstract

Mercuric oxide exists in two forms, the red and the yellow oxides. Magnetic susceptibility determinations showed no appreciable difference between the two oxides; the red one has a mass susceptibility of (—0.221₇±0.0002)·10^—6 emu/g, while the yellow one has a slightly lower mass susceptibility of (—0.216₅±0.0002)·10^—6 emu/g at room temperature (25°C). The temperature variation of their mass susceptibility between room temperature (25°C) and about 300°C was also investigated. The general shape of the curve for the two oxides is essentially the same, namely, an increase in diamagnetism with rise in temperature followed by a mild drop and subsequently a sharp rise. The position of the peak occurs at about 50°C for the red oxide and at about 114°C for the yellow oxide. A tentative explanation of their behavior was given, based on impurity ionization.