The Magnetic Susceptibilities of Palladium-Uranium Alloys

Measurements are made of the paramagnetic susceptibilities of palladium-uranium alloys covering the range of solid solution, of an intermetallic compound Pd 3 U and of specimens of very pure palladium and uranium over the temperature range 77° to 293°K. Increasing amounts of uranium cause a rapid decrease of susceptibility up to a concentration of 9 atomic per cent. Further increase in the amount of uranium causes a rapid rise in susceptibility, alloys of concentrations greater than 12 atomic per cent obeying a Curie-Weiss law with an effective atomic moment of 3.14 Bohr magnetons. The results are discussed in relation to the properties of the palladium-silver system and close similarity is found for low concentrations assuming that uranium is six times more effective than silver. The temperature-dependent susceptibilities of the alloys of higher uranium content are explained by a change in the valency of uranium leaving two unpaired electrons localized on uranium atoms. An annealed alloy of concentration 17.6 atomic per cent uranium showed an unexplained time dependence of susceptibility.