Magnetic Susceptibilities and Ionic Moments in the Palladium and Platinum Groups

Susceptibility measurements have been made on Ru, Rh, Pd, Os, Ir, and Pt and some of their compounds over a range of temperatures by means of an improved Curie balance.Pd and Pt are found to follow approximately a Curie-Weiss law. Ru, Rh, Os, and Ir are found to have paramagnetic susceptibilities which increase with temperature.Ru${\mathrm{Cl}}_{3}$ and Ir${\mathrm{O}}_{2}$ are found to follow a Curie-Weiss law which gives for the ion ${\mathrm{Ru}}^{3}$ a moment of 9.8 Weiss magnetons per mole and for ${\mathrm{Ir}}^{4}$ 13.8. The spectroscopically predicted value for each ion is 29.4. The paramagnetic susceptibility of ${\mathrm{Rh}}_{2}$${\mathrm{O}}_{3}$ is found independent of temperature while that of Ru${\mathrm{O}}_{2}$ increases rapidly with temperature. Rh${\mathrm{Cl}}_{3}$ is found to have an unmeasureably small susceptibility over the temperature range investigated. Ir${\mathrm{Cl}}_{3}$ and Pt${\mathrm{Cl}}_{2}$ are diamagnetic with susceptibilities independent of temperature.