Investigation of the Magnetic Behavior of Some Conducting Am Systems

Abstract

A number of Am compounds have been investigated by bulk magnetic and nuclear gamma resonance (NGR) measurements. For the latter type of investigations, the compounds were used as a source for the 59.6-keV resonance in 237Np. AmSb, Am3Se4, and Am3Te4 show no magnetic ordering down to 4.2 K, and the NGR isomer shifts show that the Am ions are present in the trivalent state. The susceptibility of AmSb is temperature independent. Similarly, no ordered magnetism is seen in Am2C3, although Np2C3 has a ferromagnetic transition at 109 K. These results show the tendency of conducting Am compounds to form a trivalent, nonmagnetic state. The results are discussed in terms of a crystal-field calculation which includes J mixing caused by the large crystal-field interaction present in actinide compounds.